//! Channel setup flows.
//!
//! Each channel (HTTP, Signal, WASM, etc.) has its own setup function that:
//! 1. Displays setup instructions
//! 2. Collects configuration (tokens, ports, etc.)
//! 3. Validates the configuration
//! 4. Saves secrets to the database

use std::sync::Arc;

use base64::Engine;
use secrecy::{ExposeSecret, SecretString};
use url::Url;
use uuid::Uuid;

#[cfg(feature = "postgres")]
use crate::secrets::SecretsCrypto;
use crate::secrets::{CreateSecretParams, SecretsStore};
use crate::settings::{Settings, TunnelSettings};
use crate::setup::prompts::{
    confirm, input, optional_input, print_error, print_info, print_success, print_warning,
    secret_input, select_one,
};

/// Typed errors for channel setup flows.
#[derive(Debug, thiserror::Error)]
pub enum ChannelSetupError {
    #[error("I/O error: {0}")]
    Io(#[from] std::io::Error),

    #[error("{0}")]
    Network(String),

    #[error("{0}")]
    Secrets(String),

    #[error("{0}")]
    Validation(String),

    #[error("Setup cancelled by user")]
    Cancelled,
}

/// Context for saving secrets during setup.
pub struct SecretsContext {
    store: Arc<dyn SecretsStore>,
    user_id: String,
}

impl SecretsContext {
    /// Create a new secrets context from a trait-object store.
    pub fn from_store(store: Arc<dyn SecretsStore>, user_id: &str) -> Self {
        Self {
            store,
            user_id: user_id.to_string(),
        }
    }

    /// Create a new secrets context from a PostgreSQL pool and crypto.
    #[cfg(feature = "postgres")]
    pub fn new(pool: deadpool_postgres::Pool, crypto: Arc<SecretsCrypto>, user_id: &str) -> Self {
        Self {
            store: Arc::new(crate::secrets::PostgresSecretsStore::new(pool, crypto)),
            user_id: user_id.to_string(),
        }
    }

    /// Save a secret to the database.
    pub async fn save_secret(
        &self,
        name: &str,
        value: &SecretString,
    ) -> Result<(), ChannelSetupError> {
        let params = CreateSecretParams::new(name, value.expose_secret());

        self.store
            .create(&self.user_id, params)
            .await
            .map_err(|e| ChannelSetupError::Secrets(format!("Failed to save secret: {}", e)))?;

        Ok(())
    }

    /// Check if a secret exists.
    pub async fn secret_exists(&self, name: &str) -> bool {
        match self.store.exists(&self.user_id, name).await {
            Ok(exists) => exists,
            Err(e) => {
                tracing::warn!(secret = name, error = %e, "Failed to check if secret exists, assuming absent");
                false
            }
        }
    }

    /// Read a secret from the database (decrypted).
    pub async fn get_secret(&self, name: &str) -> Result<SecretString, ChannelSetupError> {
        let decrypted = self
            .store
            .get_decrypted(&self.user_id, name)
            .await
            .map_err(|e| ChannelSetupError::Secrets(format!("Failed to read secret: {}", e)))?;
        Ok(SecretString::from(decrypted.expose().to_string()))
    }
}

/// Set up a tunnel for exposing the agent to the internet.
///
/// This is shared across all channels that need webhook endpoints.
/// Returns a `TunnelSettings` with provider config (managed tunnel)
/// or a static URL.
pub async fn setup_tunnel(settings: &Settings) -> Result<TunnelSettings, ChannelSetupError> {
    // Show existing config
    let has_existing = settings.tunnel.public_url.is_some() || settings.tunnel.provider.is_some();
    if has_existing {
        println!();
        print_info("Current tunnel configuration:");
        let t = &settings.tunnel;
        match t.provider.as_deref() {
            Some("ngrok") => {
                print_info("  Provider:  ngrok");
                if let Some(ref domain) = t.ngrok_domain {
                    print_info(&format!("  Domain:    {}", domain));
                }
                if t.ngrok_token.is_some() {
                    print_info("  Auth:      token configured");
                }
            }
            Some("cloudflare") => {
                print_info("  Provider:  Cloudflare Tunnel");
                if t.cf_token.is_some() {
                    print_info("  Auth:      token configured");
                }
            }
            Some("tailscale") => {
                let mode = if t.ts_funnel {
                    "Funnel (public)"
                } else {
                    "Serve (tailnet-only)"
                };
                print_info(&format!("  Provider:  Tailscale {}", mode));
                if let Some(ref hostname) = t.ts_hostname {
                    print_info(&format!("  Hostname:  {}", hostname));
                }
            }
            Some("custom") => {
                print_info("  Provider:  Custom command");
                if let Some(ref cmd) = t.custom_command {
                    print_info(&format!("  Command:   {}", cmd));
                }
                if let Some(ref url) = t.custom_health_url {
                    print_info(&format!("  Health:    {}", url));
                }
            }
            Some(other) => {
                print_info(&format!("  Provider:  {}", other));
            }
            None => {}
        }
        if let Some(ref url) = t.public_url {
            print_info(&format!("  URL:       {}", url));
        }
        println!();
        if !confirm("Change tunnel configuration?", false)? {
            return Ok(settings.tunnel.clone());
        }
    }

    println!();
    print_info("Tunnel Configuration (for webhook endpoints):");
    print_info("A tunnel exposes your local agent to the internet, enabling:");
    print_info("  - Instant Telegram message delivery (instead of polling)");
    print_info("  - Slack, Discord, GitHub webhooks");
    println!();

    if !confirm("Configure a tunnel?", false)? {
        return Ok(TunnelSettings::default());
    }

    let options = &[
        "ngrok         - managed tunnel, starts automatically",
        "Cloudflare    - cloudflared tunnel, starts automatically",
        "Tailscale     - Tailscale Funnel/Serve, starts automatically",
        "Custom        - your own tunnel command",
        "Static URL    - you manage the tunnel yourself",
    ];

    let choice = select_one("Select tunnel provider:", options)?;

    match choice {
        0 => setup_tunnel_ngrok(),
        1 => setup_tunnel_cloudflare().await,
        2 => setup_tunnel_tailscale(),
        3 => setup_tunnel_custom(),
        4 => setup_tunnel_static(),
        _ => Ok(TunnelSettings::default()),
    }
}

fn setup_tunnel_ngrok() -> Result<TunnelSettings, ChannelSetupError> {
    print_info("Get your auth token from: https://dashboard.ngrok.com/get-started/your-authtoken");
    println!();

    let token = secret_input("ngrok auth token")?;
    let domain = optional_input("Custom domain", Some("leave empty for auto-assigned"))?;

    print_success("ngrok configured. Tunnel will start automatically at boot.");

    Ok(TunnelSettings {
        provider: Some("ngrok".to_string()),
        ngrok_token: Some(token.expose_secret().to_string()),
        ngrok_domain: domain,
        ..Default::default()
    })
}

async fn setup_tunnel_cloudflare() -> Result<TunnelSettings, ChannelSetupError> {
    // Check if cloudflared binary is on PATH
    let cloudflared_found = crate::skills::gating::binary_exists("cloudflared");

    if !cloudflared_found {
        print_error("cloudflared not found in PATH.");
        print_info("Install it:");
        print_info("  macOS:   brew install cloudflared");
        print_info("  Ubuntu:  https://pkg.cloudflare.com/");
        print_info(
            "  Other:   https://developers.cloudflare.com/cloudflare-one/connections/connect-networks/downloads/",
        );
        println!();
        if !confirm(
            "Continue anyway (you can install cloudflared later)?",
            false,
        )? {
            return Err(ChannelSetupError::Validation(
                "cloudflared binary not found. Install it and re-run setup.".to_string(),
            ));
        }
    }

    // Detect existing cloudflared services that may conflict
    if let Some(warning) = detect_existing_cloudflared() {
        print_warning(&warning);
        if !confirm("Continue anyway?", true)? {
            return Err(ChannelSetupError::Cancelled);
        }
        println!();
    }

    print_info("Get your tunnel token from the Cloudflare Zero Trust dashboard:");
    print_info("  https://one.dash.cloudflare.com/ > Networks > Tunnels");
    println!();

    let token = secret_input("Cloudflare tunnel token")?;

    let token_valid = validate_cloudflare_token_format(token.expose_secret());

    if !token_valid {
        print_error("Token does not appear to be a valid Cloudflare tunnel token.");
        print_info("Tokens are base64-encoded and contain account/tunnel identifiers.");
        print_info(
            "Copy the full token from: Zero Trust dashboard > Networks > Tunnels > your tunnel",
        );
        println!();
        if !confirm("Save this token anyway?", false)? {
            return Err(ChannelSetupError::Validation(
                "Invalid Cloudflare tunnel token format.".to_string(),
            ));
        }
    }

    // Live-validate the token by briefly spawning cloudflared (if available)
    if cloudflared_found && token_valid {
        print_info("Verifying token with cloudflared...");
        match validate_cloudflare_token_live(token.expose_secret()).await {
            Ok(()) => {
                print_success("Token verified -- cloudflared connected successfully.");
            }
            Err(stderr_output) => {
                print_error(&format!(
                    "cloudflared rejected the token: {}",
                    stderr_output
                ));
                println!();
                if !confirm("Save this token anyway?", false)? {
                    return Err(ChannelSetupError::Validation(
                        "Cloudflare tunnel token failed live validation.".to_string(),
                    ));
                }
            }
        }
    }

    print_success("Cloudflare tunnel token saved.");
    if cloudflared_found {
        print_info("Start the tunnel with: cloudflared tunnel --no-autoupdate run --token <token>");
        print_info("For auto-start, install cloudflared as a system service:");
        print_info("  sudo cloudflared service install <token>");
    } else {
        print_info("After installing cloudflared, start the tunnel with:");
        print_info("  cloudflared tunnel --no-autoupdate run --token <token>");
    }

    Ok(TunnelSettings {
        provider: Some("cloudflare".to_string()),
        cf_token: Some(token.expose_secret().to_string()),
        ..Default::default()
    })
}

/// Detect running cloudflared processes or managed services that could conflict
/// with IronClaw's tunnel management.
fn detect_existing_cloudflared() -> Option<String> {
    #[allow(unused_mut)]
    let mut conflicts: Vec<String> = Vec::new();

    // Check for running cloudflared processes (all platforms)
    #[cfg(unix)]
    {
        let output = std::process::Command::new("pgrep")
            .args(["-x", "cloudflared"])
            .stdout(std::process::Stdio::piped())
            .stderr(std::process::Stdio::null())
            .output();
        if let Ok(out) = output
            && out.status.success()
        {
            let pids = String::from_utf8_lossy(&out.stdout);
            let pids: Vec<&str> = pids.trim().lines().collect();
            if !pids.is_empty() {
                conflicts.push(format!(
                    "Running cloudflared process(es): PID {}",
                    pids.join(", ")
                ));
            }
        }
    }

    // macOS: check brew services
    #[cfg(target_os = "macos")]
    {
        let output = std::process::Command::new("brew")
            .args(["services", "list"])
            .stdout(std::process::Stdio::piped())
            .stderr(std::process::Stdio::null())
            .output();
        if let Ok(out) = output {
            let stdout = String::from_utf8_lossy(&out.stdout);
            for line in stdout.lines() {
                if line.contains("cloudflared") && line.contains("started") {
                    conflicts.push("Homebrew service: cloudflared (started)".to_string());
                    break;
                }
            }
        }

        let output = std::process::Command::new("launchctl")
            .args(["list"])
            .stdout(std::process::Stdio::piped())
            .stderr(std::process::Stdio::null())
            .output();
        if let Ok(out) = output {
            let stdout = String::from_utf8_lossy(&out.stdout);
            for line in stdout.lines() {
                if line.contains("cloudflared") {
                    conflicts.push("launchd service: cloudflared detected".to_string());
                    break;
                }
            }
        }
    }

    // Linux: check systemd
    #[cfg(target_os = "linux")]
    {
        let output = std::process::Command::new("systemctl")
            .args(["is-active", "cloudflared"])
            .stdout(std::process::Stdio::piped())
            .stderr(std::process::Stdio::null())
            .output();
        if let Ok(out) = output {
            let stdout = String::from_utf8_lossy(&out.stdout);
            if stdout.trim() == "active" {
                conflicts.push("systemd service: cloudflared (active)".to_string());
            }
        }
    }

    if conflicts.is_empty() {
        None
    } else {
        Some(format!(
            "Detected existing cloudflared service(s) that may conflict:\n  {}\n\
             Consider stopping them first (e.g., `brew services stop cloudflared` or \
             `sudo systemctl stop cloudflared`).",
            conflicts.join("\n  ")
        ))
    }
}

fn setup_tunnel_tailscale() -> Result<TunnelSettings, ChannelSetupError> {
    let funnel = confirm("Use Tailscale Funnel (public internet)?", true)?;
    let hostname = optional_input("Hostname override", Some("leave empty for auto-detect"))?;

    let mode = if funnel {
        "Funnel (public)"
    } else {
        "Serve (tailnet-only)"
    };
    print_success(&format!("Tailscale {} configured.", mode));

    Ok(TunnelSettings {
        provider: Some("tailscale".to_string()),
        ts_funnel: funnel,
        ts_hostname: hostname,
        ..Default::default()
    })
}

fn setup_tunnel_custom() -> Result<TunnelSettings, ChannelSetupError> {
    print_info("Enter a shell command to start your tunnel.");
    print_info("Use {port} and {host} as placeholders.");
    print_info("Example: bore local {port} --to bore.pub");
    println!();

    let command = input("Tunnel command")?;
    if command.is_empty() {
        return Err(ChannelSetupError::Validation(
            "Tunnel command cannot be empty".to_string(),
        ));
    }

    let health_url = optional_input("Health check URL", Some("optional"))?;
    let url_pattern = optional_input(
        "URL pattern (substring to match in stdout)",
        Some("optional"),
    )?;

    print_success("Custom tunnel configured.");

    Ok(TunnelSettings {
        provider: Some("custom".to_string()),
        custom_command: Some(command),
        custom_health_url: health_url,
        custom_url_pattern: url_pattern,
        ..Default::default()
    })
}

fn setup_tunnel_static() -> Result<TunnelSettings, ChannelSetupError> {
    print_info("Enter the public URL of your externally managed tunnel.");
    println!();

    let tunnel_url = input("Tunnel URL (e.g., https://abc123.ngrok.io)")?;

    if !tunnel_url.starts_with("https://") {
        print_error("URL must start with https:// (webhooks require HTTPS)");
        return Err(ChannelSetupError::Validation(
            "Invalid tunnel URL: must use HTTPS".to_string(),
        ));
    }

    let tunnel_url = tunnel_url.trim_end_matches('/').to_string();

    print_success(&format!("Static tunnel URL configured: {}", tunnel_url));
    print_info("Make sure your tunnel is running before starting the agent.");

    Ok(TunnelSettings {
        public_url: Some(tunnel_url),
        ..Default::default()
    })
}

/// Result of HTTP webhook setup.
#[derive(Debug, Clone)]
pub struct HttpSetupResult {
    pub enabled: bool,
    pub port: u16,
    pub host: String,
}

/// Result of Signal channel setup.
#[derive(Debug, Clone)]
pub struct SignalSetupResult {
    pub enabled: bool,
    pub http_url: String,
    pub account: String,
    pub allow_from: String,
    pub allow_from_groups: String,
    pub dm_policy: String,
    pub group_policy: String,
    pub group_allow_from: String,
}

/// Set up HTTP webhook channel.
pub async fn setup_http(secrets: &SecretsContext) -> Result<HttpSetupResult, ChannelSetupError> {
    println!("HTTP Webhook Setup:");
    println!();
    print_info("The HTTP webhook allows external services to send messages to the agent.");
    println!();

    let port_str = optional_input("Port", Some("default: 8080"))?;
    let port: u16 = port_str
        .as_deref()
        .unwrap_or("8080")
        .parse()
        .map_err(|e| ChannelSetupError::Validation(format!("Invalid port: {}", e)))?;

    if port < 1024 {
        print_info("Note: Ports below 1024 may require root privileges");
    }

    let host =
        optional_input("Host", Some("default: 0.0.0.0"))?.unwrap_or_else(|| "0.0.0.0".to_string());

    // Generate a webhook secret
    if confirm("Generate a webhook secret for authentication?", true)? {
        let secret = generate_webhook_secret();
        secrets
            .save_secret("http_webhook_secret", &SecretString::from(secret))
            .await?;
        print_success("Webhook secret generated and saved to database");
        print_info("Retrieve it later with: ironclaw secret get http_webhook_secret");
    }

    print_success(&format!("HTTP webhook will listen on {}:{}", host, port));

    Ok(HttpSetupResult {
        enabled: true,
        port,
        host,
    })
}

/// Generate a random webhook secret.
pub fn generate_webhook_secret() -> String {
    generate_secret_with_length(32)
}

fn validate_e164(account: &str) -> Result<(), String> {
    if !account.starts_with('+') {
        return Err("E.164 account must start with '+'".to_string());
    }
    let digits = &account[1..];
    if digits.is_empty() {
        return Err("E.164 account must have digits after '+'".to_string());
    }
    if !digits.chars().all(|c| c.is_ascii_digit()) {
        return Err("E.164 account must contain only digits after '+'".to_string());
    }
    if digits.len() < 7 || digits.len() > 15 {
        return Err("E.164 account must be 7-15 digits after '+'".to_string());
    }
    Ok(())
}

fn validate_allow_from_list(list: &str) -> Result<(), String> {
    if list.is_empty() {
        return Ok(());
    }
    for (i, item) in list.split(',').enumerate() {
        let trimmed = item.trim();
        if trimmed.is_empty() {
            continue;
        }
        if trimmed == "*" {
            continue;
        }
        if let Some(uuid_part) = trimmed.strip_prefix("uuid:") {
            if Uuid::parse_str(uuid_part).is_err() {
                return Err(format!(
                    "allow_from[{}]: '{}' is not a valid UUID (after 'uuid:' prefix)",
                    i, trimmed
                ));
            }
            continue;
        }
        if validate_e164(trimmed).is_ok() {
            continue;
        }
        if Uuid::parse_str(trimmed).is_ok() {
            continue;
        }
        return Err(format!(
            "allow_from[{}]: '{}' must be '*', E.164 phone number, UUID, or 'uuid:<id>'",
            i, trimmed
        ));
    }
    Ok(())
}

fn validate_allow_from_groups_list(list: &str) -> Result<(), String> {
    if list.is_empty() {
        return Ok(());
    }
    for (i, item) in list.split(',').enumerate() {
        let trimmed = item.trim();
        if trimmed.is_empty() {
            continue;
        }
        if trimmed == "*" {
            continue;
        }
        if trimmed.is_empty() {
            return Err(format!(
                "allow_from_groups[{}]: group ID cannot be empty",
                i
            ));
        }
    }
    Ok(())
}

/// Set up Signal channel.
/// `Settings` is reserved for future use
pub async fn setup_signal(_settings: &Settings) -> Result<SignalSetupResult, ChannelSetupError> {
    println!("Signal Channel Setup:");
    println!();
    print_info("Signal channel connects to a signal-cli daemon running in HTTP mode.");
    println!();

    let http_url = input("Signal-cli HTTP URL")?;
    match Url::parse(&http_url) {
        Ok(url) if url.scheme() == "http" || url.scheme() == "https" => {}
        Ok(_) => {
            print_error("URL must use http or https scheme");
            return Err(ChannelSetupError::Validation(
                "Invalid HTTP URL: must use http or https scheme".to_string(),
            ));
        }
        Err(e) => {
            print_error(&format!("Invalid URL: {}", e));
            return Err(ChannelSetupError::Validation(format!(
                "Invalid HTTP URL: {}",
                e
            )));
        }
    }

    let account = input("Signal account (E.164)")?;
    if let Err(e) = validate_e164(&account) {
        print_error(&e);
        return Err(ChannelSetupError::Validation(e));
    }

    let allow_from = optional_input(
        "Allow from (comma-separated: E.164 numbers, '*' for anyone, UUIDs or 'uuid:<id>'; empty for self-only)",
        Some(&format!("default: {} (self-only)", account)),
    )?
    .unwrap_or_else(|| account.clone());

    let dm_policy = optional_input(
        "DM policy (open, allowlist, pairing)",
        Some("default: pairing"),
    )?
    .unwrap_or_else(|| "pairing".to_string());

    let allow_from_groups = optional_input(
        "Allow from groups (comma-separated group IDs, '*' for any group; empty for none)",
        Some("default: (none)"),
    )?
    .unwrap_or_default();

    let group_policy = optional_input(
        "Group policy (allowlist, open, disabled)",
        Some("default: allowlist"),
    )?
    .unwrap_or_else(|| "allowlist".to_string());

    let group_allow_from = optional_input(
        "Group allow from (comma-separated member IDs; empty to inherit from allow_from)",
        Some("default: (inherit from allow_from)"),
    )?
    .unwrap_or_default();

    if let Err(e) = validate_allow_from_list(&allow_from) {
        print_error(&e);
        return Err(ChannelSetupError::Validation(e));
    }

    if let Err(e) = validate_allow_from_groups_list(&allow_from_groups) {
        print_error(&e);
        return Err(ChannelSetupError::Validation(e));
    }

    println!();
    print_success(&format!(
        "Signal channel configured for account: {}",
        account
    ));
    print_info(&format!("HTTP URL: {}", http_url));
    if allow_from == account {
        print_info("Allow from: self-only");
    } else {
        print_info(&format!("Allow from: {}", allow_from));
    }
    print_info(&format!("DM policy: {}", dm_policy));
    if allow_from_groups.is_empty() {
        print_info("Allow from groups: (none)");
    } else {
        print_info(&format!("Allow from groups: {}", allow_from_groups));
    }
    print_info(&format!("Group policy: {}", group_policy));
    if group_allow_from.is_empty() {
        print_info("Group allow from: (inherits from allow_from)");
    } else {
        print_info(&format!("Group allow from: {}", group_allow_from));
    }

    Ok(SignalSetupResult {
        enabled: true,
        http_url,
        account,
        allow_from,
        allow_from_groups,
        dm_policy,
        group_policy,
        group_allow_from,
    })
}

/// Result of WASM channel setup.
#[derive(Debug, Clone)]
pub struct WasmChannelSetupResult {
    pub enabled: bool,
    pub channel_name: String,
}

/// Set up a WASM channel using its capabilities file setup schema.
///
/// Reads setup requirements from the channel's capabilities file and
/// prompts the user for each required secret.
pub async fn setup_wasm_channel(
    secrets: &SecretsContext,
    channel_name: &str,
    setup: &crate::channels::wasm::SetupSchema,
) -> Result<WasmChannelSetupResult, ChannelSetupError> {
    println!("{} Setup:", channel_name);
    println!();

    for secret_config in &setup.required_secrets {
        // Check if this secret already exists
        if secrets.secret_exists(&secret_config.name).await {
            print_info(&format!(
                "Existing {} found in database.",
                secret_config.name
            ));
            if !confirm("Replace existing value?", false)? {
                continue;
            }
        }

        // Get the value from user or auto-generate
        let value = if secret_config.optional {
            let input_value =
                optional_input(&secret_config.prompt, Some("leave empty to auto-generate"))?;

            if let Some(v) = input_value {
                if !v.is_empty() {
                    SecretString::from(v)
                } else if let Some(ref auto_gen) = secret_config.auto_generate {
                    let generated = generate_secret_with_length(auto_gen.length);
                    print_info(&format!(
                        "Auto-generated {} ({} bytes)",
                        secret_config.name, auto_gen.length
                    ));
                    SecretString::from(generated)
                } else {
                    continue; // Skip optional secret with no auto-generate
                }
            } else if let Some(ref auto_gen) = secret_config.auto_generate {
                let generated = generate_secret_with_length(auto_gen.length);
                print_info(&format!(
                    "Auto-generated {} ({} bytes)",
                    secret_config.name, auto_gen.length
                ));
                SecretString::from(generated)
            } else {
                continue; // Skip optional secret with no auto-generate
            }
        } else {
            // Required secret
            let input_value = secret_input(&secret_config.prompt)?;

            // Validate if pattern is provided
            if let Some(ref pattern) = secret_config.validation {
                let re = regex::Regex::new(pattern).map_err(|e| {
                    ChannelSetupError::Validation(format!("Invalid validation pattern: {}", e))
                })?;
                if !re.is_match(input_value.expose_secret()) {
                    print_error(&format!(
                        "Value does not match expected format: {}",
                        pattern
                    ));
                    return Err(ChannelSetupError::Validation(
                        "Validation failed".to_string(),
                    ));
                }
            }

            input_value
        };

        // Save the secret
        secrets.save_secret(&secret_config.name, &value).await?;
        print_success(&format!("{} saved to database", secret_config.name));
    }

    if let Some(ref validation_endpoint) = setup.validation_endpoint {
        print_info("Validating configured credentials...");
        match validate_channel_credentials(secrets, validation_endpoint).await {
            Ok(()) => print_success("Credentials validated successfully"),
            Err(e) => print_warning(&format!(
                "Credential validation failed: {}. Setup will continue, but the channel may fail to start until the credentials are fixed.",
                e
            )),
        }
    }

    print_success(&format!("{} channel configured", channel_name));

    Ok(WasmChannelSetupResult {
        enabled: true,
        channel_name: channel_name.to_string(),
    })
}

async fn validate_channel_credentials(
    secrets: &SecretsContext,
    validation_endpoint: &str,
) -> Result<(), ChannelSetupError> {
    let validation_url = substitute_validation_placeholders(secrets, validation_endpoint).await?;
    let (parsed, resolved_addrs) = validate_public_https_url(&validation_url).await?;
    let target = validation_target_display(&parsed);
    let mut client_builder = reqwest::Client::builder()
        .timeout(std::time::Duration::from_secs(5))
        .redirect(reqwest::redirect::Policy::none());

    if matches!(parsed.host(), Some(url::Host::Domain(_)))
        && let Some(host) = parsed.host_str()
    {
        client_builder = client_builder.resolve_to_addrs(host, &resolved_addrs);
    }

    let client = client_builder
        .build()
        .map_err(|e| ChannelSetupError::Network(format!("Failed to build HTTP client: {}", e)))?;

    let response = client.get(parsed.clone()).send().await.map_err(|e| {
        ChannelSetupError::Network(format!(
            "Validation request to {} failed: {}",
            target,
            describe_validation_request_error(&e)
        ))
    })?;

    if response.status().is_success() {
        Ok(())
    } else {
        Err(ChannelSetupError::Validation(format!(
            "Validation endpoint returned HTTP {} from {}",
            response.status(),
            target
        )))
    }
}

async fn substitute_validation_placeholders(
    secrets: &SecretsContext,
    validation_endpoint: &str,
) -> Result<String, ChannelSetupError> {
    let mut resolved = validation_endpoint.to_string();
    let placeholder_names: std::collections::BTreeSet<String> = validation_placeholder_regex()
        .captures_iter(validation_endpoint)
        .filter_map(|caps| caps.get(1).map(|m| m.as_str().to_string()))
        .collect();

    for secret_name in placeholder_names {
        let secret_value = secrets.get_secret(&secret_name).await?;
        let placeholder = format!("{{{}}}", secret_name);
        let encoded_value = urlencoding::encode(secret_value.expose_secret());
        resolved = resolved.replace(&placeholder, encoded_value.as_ref());
    }

    Ok(resolved)
}

async fn validate_public_https_url(
    url: &str,
) -> Result<(Url, Vec<std::net::SocketAddr>), ChannelSetupError> {
    use std::net::{IpAddr, SocketAddr};

    let parsed = Url::parse(url)
        .map_err(|e| ChannelSetupError::Validation(format!("Invalid URL: {}", e)))?;

    if parsed.scheme() != "https" {
        return Err(ChannelSetupError::Validation(
            "Validation endpoint must use https".to_string(),
        ));
    }

    if !parsed.username().is_empty() || parsed.password().is_some() {
        return Err(ChannelSetupError::Validation(
            "Validation endpoint cannot contain userinfo".to_string(),
        ));
    }

    let host = parsed
        .host_str()
        .ok_or_else(|| ChannelSetupError::Validation("Validation URL missing host".to_string()))?;
    let normalized_host = normalize_validation_domain(host);
    let host_lower = normalized_host.to_ascii_lowercase();

    if host_lower == "localhost" || host_lower.ends_with(".localhost") {
        return Err(ChannelSetupError::Validation(
            "Validation endpoint cannot target localhost".to_string(),
        ));
    }

    let port = parsed.port_or_known_default().unwrap_or(443);

    match parsed
        .host()
        .ok_or_else(|| ChannelSetupError::Validation("Validation URL missing host".to_string()))?
    {
        url::Host::Ipv4(v4) => {
            let ip = IpAddr::V4(v4);
            if is_disallowed_ip(&ip) {
                return Err(ChannelSetupError::Validation(format!(
                    "Validation endpoint cannot target private or local IP {}",
                    ip
                )));
            }

            Ok((parsed, vec![SocketAddr::new(ip, port)]))
        }
        url::Host::Ipv6(v6) => {
            let ip = normalize_ip(IpAddr::V6(v6));
            if is_disallowed_ip(&ip) {
                return Err(ChannelSetupError::Validation(format!(
                    "Validation endpoint cannot target private or local IP {}",
                    ip
                )));
            }

            Ok((parsed, vec![SocketAddr::new(ip, port)]))
        }
        url::Host::Domain(domain) => {
            let addrs: Vec<SocketAddr> = tokio::net::lookup_host((normalized_host, port))
                .await
                .map_err(|e| {
                    ChannelSetupError::Validation(format!(
                        "DNS resolution failed for {}: {}",
                        normalized_host, e
                    ))
                })?
                .map(|addr| SocketAddr::new(normalize_ip(addr.ip()), addr.port()))
                .collect();

            if addrs.is_empty() {
                return Err(ChannelSetupError::Validation(format!(
                    "Validation hostname '{}' did not resolve to any IP addresses",
                    domain
                )));
            }

            for addr in &addrs {
                if is_disallowed_ip(&addr.ip()) {
                    return Err(ChannelSetupError::Validation(format!(
                        "Validation hostname '{}' resolves to disallowed IP {}",
                        domain,
                        addr.ip()
                    )));
                }
            }

            Ok((parsed, addrs))
        }
    }
}

fn is_disallowed_ip(ip: &std::net::IpAddr) -> bool {
    match normalize_ip(*ip) {
        std::net::IpAddr::V4(v4) => {
            v4.is_private()
                || v4.is_loopback()
                || v4.is_link_local()
                || v4.is_multicast()
                || v4.is_unspecified()
                || v4 == std::net::Ipv4Addr::new(169, 254, 169, 254)
                || (v4.octets()[0] == 100 && (v4.octets()[1] & 0xC0) == 64)
        }
        std::net::IpAddr::V6(v6) => {
            v6.is_loopback()
                || v6.is_unique_local()
                || v6.is_unicast_link_local()
                || v6.is_multicast()
                || v6.is_unspecified()
        }
    }
}

fn normalize_ip(ip: std::net::IpAddr) -> std::net::IpAddr {
    match ip {
        std::net::IpAddr::V6(v6) => v6
            .to_ipv4_mapped()
            .map(std::net::IpAddr::V4)
            .unwrap_or(std::net::IpAddr::V6(v6)),
        other => other,
    }
}

fn normalize_validation_domain(host: &str) -> &str {
    host.trim_end_matches('.')
}

fn validation_placeholder_regex() -> &'static regex::Regex {
    static PLACEHOLDER_RE: std::sync::OnceLock<regex::Regex> = std::sync::OnceLock::new();
    PLACEHOLDER_RE.get_or_init(|| {
        regex::Regex::new(r"\{([A-Za-z0-9_]+)\}")
            .expect("validation placeholder regex must compile") // safety: hardcoded literal
    })
}

fn validation_target_display(parsed: &Url) -> String {
    let host = parsed.host_str().unwrap_or("unknown host");
    match parsed.port() {
        Some(port) => format!("{}:{}", host, port),
        None => host.to_string(),
    }
}

fn describe_validation_request_error(error: &reqwest::Error) -> &'static str {
    if error.is_timeout() {
        "request timed out"
    } else if error.is_redirect() {
        "redirects are not allowed"
    } else if error.is_connect() {
        "connection failed"
    } else if error.is_request() {
        "request could not be sent"
    } else {
        "request failed"
    }
}

/// Validate a Cloudflare tunnel token by briefly running `cloudflared`.
///
/// Spawns `cloudflared tunnel run` with a dummy local URL and watches stderr
/// for up to 10 seconds. If a connection URL appears, the token is valid.
/// If error indicators appear first, returns the error message.
async fn validate_cloudflare_token_live(token: &str) -> Result<(), String> {
    use tokio::io::AsyncBufReadExt;
    use tokio::process::Command;

    let mut child = Command::new("cloudflared")
        .args([
            "tunnel",
            "--no-autoupdate",
            "run",
            "--token",
            token,
            "--url",
            "http://localhost:1",
        ])
        .stdout(std::process::Stdio::null())
        .stderr(std::process::Stdio::piped())
        .kill_on_drop(true)
        .spawn()
        .map_err(|e| format!("Failed to spawn cloudflared: {}", e))?;

    let stderr = child
        .stderr
        .take()
        .ok_or_else(|| "Failed to capture cloudflared stderr".to_string())?;
    let mut reader = tokio::io::BufReader::new(stderr).lines();

    let result = tokio::time::timeout(std::time::Duration::from_secs(10), async {
        while let Ok(Some(line)) = reader.next_line().await {
            // A successful connection logs a URL like "https://xxx.cfargotunnel.com"
            if line.contains("https://")
                && (line.contains("cfargotunnel.com") || line.contains("trycloudflare.com"))
            {
                return Ok(());
            }
            // Error indicators that appear before a URL mean the token is bad
            let lower = line.to_lowercase();
            if lower.starts_with("err")
                || lower.contains("failed to unmarshal")
                || lower.contains("unauthorized")
            {
                return Err(line);
            }
        }
        // Process exited without clear signal -- check exit status
        Err("cloudflared exited without establishing a connection".to_string())
    })
    .await;

    // Ensure the process is killed regardless of outcome
    let _ = child.kill().await;

    match result {
        Ok(inner) => inner,
        Err(_elapsed) => {
            // Timed out without error or success -- benefit of the doubt
            Ok(())
        }
    }
}

/// Validate that a Cloudflare tunnel token has the expected format.
///
/// Cloudflare tunnel tokens are base64-encoded JSON objects containing
/// at least `"a"` (account tag) and `"t"` (tunnel ID) fields.
fn validate_cloudflare_token_format(token: &str) -> bool {
    base64::engine::general_purpose::STANDARD
        .decode(token)
        .or_else(|_| base64::engine::general_purpose::URL_SAFE.decode(token))
        .ok()
        .and_then(|bytes| serde_json::from_slice::<serde_json::Value>(&bytes).ok())
        .is_some_and(|json| json.get("a").is_some() && json.get("t").is_some())
}

/// Generate a random secret of specified length (in bytes).
fn generate_secret_with_length(length: usize) -> String {
    use rand::RngCore;
    use rand::rngs::OsRng;
    let mut bytes = vec![0u8; length];
    OsRng.fill_bytes(&mut bytes);
    bytes.iter().map(|b| format!("{:02x}", b)).collect()
}

#[cfg(test)]
mod tests {
    use base64::Engine;
    use std::sync::Arc;

    use crate::secrets::{InMemorySecretsStore, SecretsCrypto, SecretsStore};
    use crate::setup::channels::{
        SecretsContext, generate_webhook_secret, substitute_validation_placeholders,
        validate_cloudflare_token_format, validate_public_https_url,
    };

    fn test_secrets_context() -> SecretsContext {
        use secrecy::SecretString;

        let crypto = Arc::new(
            SecretsCrypto::new(SecretString::from(
                "0123456789abcdef0123456789abcdef".to_string(),
            ))
            .unwrap(),
        );
        let store: Arc<dyn SecretsStore> = Arc::new(InMemorySecretsStore::new(crypto));
        SecretsContext::from_store(store, "test-user")
    }

    #[test]
    fn test_generate_webhook_secret() {
        let secret = generate_webhook_secret();
        assert_eq!(secret.len(), 64); // 32 bytes = 64 hex chars
    }

    #[test]
    fn test_generate_secret_with_length() {
        use super::generate_secret_with_length;

        let s = generate_secret_with_length(16);
        assert_eq!(s.len(), 32); // 16 bytes = 32 hex chars
        assert!(s.chars().all(|c| c.is_ascii_hexdigit()));

        let s2 = generate_secret_with_length(1);
        assert_eq!(s2.len(), 2);
    }

    #[test]
    fn test_validate_cloudflare_token_valid() {
        // Simulate a valid Cloudflare tunnel token: base64-encoded JSON with "a" and "t" fields
        let payload = serde_json::json!({"a": "account-tag", "t": "tunnel-id", "s": "secret"});
        let token =
            base64::engine::general_purpose::STANDARD.encode(payload.to_string().as_bytes());
        assert!(validate_cloudflare_token_format(&token));
    }

    #[test]
    fn test_validate_cloudflare_token_missing_fields() {
        // JSON but missing required "a" and "t" fields
        let payload = serde_json::json!({"foo": "bar"});
        let token =
            base64::engine::general_purpose::STANDARD.encode(payload.to_string().as_bytes());
        assert!(!validate_cloudflare_token_format(&token));
    }

    #[test]
    fn test_validate_cloudflare_token_not_base64() {
        assert!(!validate_cloudflare_token_format("not-base64!!!"));
    }

    #[test]
    fn test_validate_cloudflare_token_not_json() {
        let token = base64::engine::general_purpose::STANDARD.encode(b"not json at all");
        assert!(!validate_cloudflare_token_format(&token));
    }

    #[test]
    fn test_validate_cloudflare_token_empty() {
        assert!(!validate_cloudflare_token_format(""));
    }

    #[tokio::test]
    async fn test_substitute_validation_placeholders() {
        let secrets = test_secrets_context();
        secrets
            .save_secret(
                "telegram_bot_token",
                &secrecy::SecretString::from("abc123".to_string()),
            )
            .await
            .unwrap();
        secrets
            .save_secret(
                "workspace_id",
                &secrecy::SecretString::from("ws_456".to_string()),
            )
            .await
            .unwrap();

        let resolved = substitute_validation_placeholders(
            &secrets,
            "https://api.example.com/{workspace_id}/verify?token={telegram_bot_token}",
        )
        .await
        .unwrap();

        assert_eq!(
            resolved,
            "https://api.example.com/ws_456/verify?token=abc123"
        );
    }

    #[tokio::test]
    async fn test_substitute_validation_placeholders_url_encodes_secrets() {
        let secrets = test_secrets_context();
        secrets
            .save_secret(
                "telegram_bot_token",
                &secrecy::SecretString::from("abc123?foo=1&bar=#baz/slash".to_string()),
            )
            .await
            .unwrap();

        let resolved = substitute_validation_placeholders(
            &secrets,
            "https://api.example.com/verify?token={telegram_bot_token}",
        )
        .await
        .unwrap();

        assert_eq!(
            resolved,
            "https://api.example.com/verify?token=abc123%3Ffoo%3D1%26bar%3D%23baz%2Fslash"
        );
    }

    #[tokio::test]
    async fn test_substitute_validation_placeholders_missing_secret() {
        let secrets = test_secrets_context();
        let err = substitute_validation_placeholders(
            &secrets,
            "https://api.example.com/verify?token={missing_secret}",
        )
        .await
        .unwrap_err()
        .to_string();

        assert!(err.contains("Failed to read secret"));
    }

    #[tokio::test]
    async fn test_validate_public_https_url_rejects_localhost() {
        let err = validate_public_https_url("https://localhost/api")
            .await
            .unwrap_err()
            .to_string();
        assert!(err.contains("localhost"));
    }

    #[tokio::test]
    async fn test_validate_public_https_url_rejects_localhost_with_trailing_dot() {
        let err = validate_public_https_url("https://localhost./api")
            .await
            .unwrap_err()
            .to_string();
        assert!(err.contains("localhost"));
    }

    #[tokio::test]
    async fn test_validate_public_https_url_rejects_private_ip() {
        let err = validate_public_https_url("https://192.168.1.10/api")
            .await
            .unwrap_err()
            .to_string();
        assert!(err.contains("private or local IP"));
    }

    #[tokio::test]
    async fn test_validate_public_https_url_rejects_ipv4_mapped_ipv6() {
        let err = validate_public_https_url("https://[::ffff:127.0.0.1]/api")
            .await
            .unwrap_err()
            .to_string();
        assert!(err.contains("private or local IP"));
    }

    #[tokio::test]
    async fn test_validate_public_https_url_rejects_http() {
        let err = validate_public_https_url("http://example.com/api")
            .await
            .unwrap_err()
            .to_string();
        assert!(err.contains("must use https"));
    }

    #[tokio::test]
    async fn test_validate_public_https_url_accepts_public_https_literal_ip() {
        let (parsed, addrs) = validate_public_https_url("https://8.8.8.8/api")
            .await
            .unwrap();
        assert_eq!(parsed.as_str(), "https://8.8.8.8/api");
        assert_eq!(addrs.len(), 1);
        assert_eq!(addrs[0].ip().to_string(), "8.8.8.8");
    }

    #[tokio::test]
    async fn test_validate_public_https_url_fails_closed_on_dns_error() {
        let err = validate_public_https_url("https://should-not-resolve.invalid/api")
            .await
            .unwrap_err()
            .to_string();
        assert!(err.contains("DNS resolution failed"));
    }
}