//! `ironclaw routines` — manage scheduled routines from the CLI.
//!
//! Provides subcommands for listing, creating, editing, enabling/disabling,
//! deleting, and viewing run history of routines without starting the full agent.

use std::sync::Arc;

use chrono::{DateTime, Utc};
use clap::Subcommand;
use uuid::Uuid;

use crate::agent::routine::{
    NotifyConfig, Routine, RoutineAction, RoutineGuardrails, Trigger, next_cron_fire,
};
use crate::db::Database;

/// Routines subcommands.
#[derive(Subcommand, Debug, Clone)]
pub enum RoutinesCommand {
    /// List routines
    List {
        /// Filter by trigger type (e.g. "cron", "webhook", "event")
        #[arg(long)]
        trigger: Option<String>,

        /// Include disabled routines
        #[arg(long)]
        disabled: bool,

        /// Output as JSON (for scripting)
        #[arg(long)]
        json: bool,
    },

    /// Create a new cron routine
    #[command(alias = "add")]
    Create {
        /// Routine name (must be unique per user)
        #[arg(long)]
        name: String,

        /// Cron schedule (6-field: "sec min hour day month weekday")
        #[arg(long)]
        schedule: String,

        /// Prompt for the LLM
        #[arg(long)]
        prompt: String,

        /// Optional description
        #[arg(long, default_value = "")]
        description: String,

        /// IANA timezone (e.g. "America/New_York")
        #[arg(long)]
        timezone: Option<String>,

        /// Cooldown between fires in seconds
        #[arg(long, default_value = "300")]
        cooldown: u64,

        /// Notification channel
        #[arg(long)]
        notify_channel: Option<String>,
    },

    /// Edit an existing routine
    #[command(alias = "update")]
    Edit {
        /// Routine name
        #[arg(long)]
        name: String,

        /// New schedule
        #[arg(long)]
        schedule: Option<String>,

        /// New prompt
        #[arg(long)]
        prompt: Option<String>,

        /// New description
        #[arg(long)]
        description: Option<String>,

        /// New timezone
        #[arg(long)]
        timezone: Option<String>,

        /// New cooldown in seconds
        #[arg(long)]
        cooldown: Option<u64>,
    },

    /// Enable a routine
    Enable {
        /// Routine name
        name: String,
    },

    /// Disable a routine
    Disable {
        /// Routine name
        name: String,
    },

    /// Delete a routine
    #[command(alias = "rm")]
    Delete {
        /// Routine name
        name: String,

        /// Skip confirmation prompt
        #[arg(short, long)]
        yes: bool,
    },

    /// Show run history for a routine
    #[command(alias = "runs")]
    History {
        /// Routine name
        name: String,

        /// Maximum number of runs to show
        #[arg(short, long, default_value = "10")]
        limit: i64,

        /// Output as JSON (for scripting)
        #[arg(long)]
        json: bool,
    },
}

/// Run a routines CLI command against the database.
pub async fn run_routines_command(
    cmd: RoutinesCommand,
    db: Arc<dyn Database>,
    user_id: &str,
) -> anyhow::Result<()> {
    match cmd {
        RoutinesCommand::List {
            trigger,
            disabled,
            json,
        } => list(&db, user_id, trigger.as_deref(), disabled, json).await,
        RoutinesCommand::Create {
            name,
            schedule,
            prompt,
            description,
            timezone,
            cooldown,
            notify_channel,
        } => {
            create(
                &db,
                user_id,
                &name,
                &schedule,
                &prompt,
                &description,
                timezone.as_deref(),
                cooldown,
                notify_channel,
            )
            .await
        }
        RoutinesCommand::Edit {
            name,
            schedule,
            prompt,
            description,
            timezone,
            cooldown,
        } => {
            edit(
                &db,
                user_id,
                &name,
                schedule.as_deref(),
                prompt.as_deref(),
                description.as_deref(),
                timezone.as_deref(),
                cooldown,
            )
            .await
        }
        RoutinesCommand::Enable { name } => set_enabled(&db, user_id, &name, true).await,
        RoutinesCommand::Disable { name } => set_enabled(&db, user_id, &name, false).await,
        RoutinesCommand::Delete { name, yes } => delete(&db, user_id, &name, yes).await,
        RoutinesCommand::History { name, limit, json } => {
            history(&db, user_id, &name, limit, json).await
        }
    }
}

// ── List ────────────────────────────────────────────────────

async fn list(
    db: &Arc<dyn Database>,
    user_id: &str,
    trigger_filter: Option<&str>,
    show_disabled: bool,
    json: bool,
) -> anyhow::Result<()> {
    let routines = db.list_routines(user_id).await?;

    let filtered: Vec<&Routine> = routines
        .iter()
        .filter(|r| {
            trigger_filter
                .map(|t| r.trigger.type_tag() == t)
                .unwrap_or(true)
        })
        .filter(|r| show_disabled || r.enabled)
        .collect();

    if json {
        let items: Vec<serde_json::Value> = filtered
            .iter()
            .map(|r| {
                serde_json::json!({
                    "id": r.id.to_string(),
                    "name": r.name,
                    "trigger": r.trigger.type_tag(),
                    "enabled": r.enabled,
                    "next_fire_at": r.next_fire_at,
                    "last_run_at": r.last_run_at,
                    "run_count": r.run_count,
                    "consecutive_failures": r.consecutive_failures,
                })
            })
            .collect();
        println!("{}", serde_json::to_string_pretty(&items)?);
        return Ok(());
    }

    if filtered.is_empty() {
        if let Some(t) = trigger_filter {
            println!("No {t} routines found.");
        } else {
            println!("No routines found.");
        }
        return Ok(());
    }

    // Header
    println!(
        "{:<36}  {:<20}  {:<8}  {:<8}  {:<22}  {:<22}  {:>5}",
        "ID", "NAME", "TRIGGER", "STATUS", "NEXT FIRE", "LAST RUN", "RUNS"
    );
    println!("{}", "-".repeat(130));

    for r in &filtered {
        let status = if r.enabled {
            if r.consecutive_failures > 0 {
                format!("err({})", r.consecutive_failures)
            } else {
                "active".to_string()
            }
        } else {
            "disabled".to_string()
        };

        let next_fire = r
            .next_fire_at
            .map(format_relative)
            .unwrap_or_else(|| "-".to_string());

        let last_run = r
            .last_run_at
            .map(format_relative)
            .unwrap_or_else(|| "-".to_string());

        let name = truncate(&r.name, 20);

        println!(
            "{:<36}  {:<20}  {:<8}  {:<8}  {:<22}  {:<22}  {:>5}",
            r.id,
            name,
            r.trigger.type_tag(),
            status,
            next_fire,
            last_run,
            r.run_count,
        );
    }

    println!("\n{} routine(s)", filtered.len());
    Ok(())
}

// ── Create ──────────────────────────────────────────────────

#[allow(clippy::too_many_arguments)]
async fn create(
    db: &Arc<dyn Database>,
    user_id: &str,
    name: &str,
    schedule: &str,
    prompt: &str,
    description: &str,
    timezone: Option<&str>,
    cooldown_secs: u64,
    notify_channel: Option<String>,
) -> anyhow::Result<()> {
    validate_timezone_arg(timezone)?;

    // Validate the cron expression by computing next fire.
    let next_fire = next_cron_fire(schedule, timezone)
        .map_err(|e| anyhow::anyhow!("Invalid cron schedule: {e}"))?;

    // Check for name conflict.
    if db.get_routine_by_name(user_id, name).await?.is_some() {
        anyhow::bail!("Routine '{}' already exists", name);
    }

    let now = Utc::now();
    let routine = Routine {
        id: Uuid::new_v4(),
        name: name.to_string(),
        description: description.to_string(),
        user_id: user_id.to_string(),
        enabled: true,
        trigger: Trigger::Cron {
            schedule: schedule.to_string(),
            timezone: timezone.map(String::from),
        },
        action: RoutineAction::Lightweight {
            prompt: prompt.to_string(),
            context_paths: Vec::new(),
            max_tokens: 4096,
            use_tools: false,
            max_tool_rounds: 0,
        },
        guardrails: RoutineGuardrails {
            cooldown: std::time::Duration::from_secs(cooldown_secs),
            max_concurrent: 1,
            dedup_window: None,
        },
        notify: NotifyConfig {
            channel: notify_channel,
            user: user_id.to_string(),
            on_attention: true,
            on_failure: true,
            on_success: false,
        },
        last_run_at: None,
        next_fire_at: next_fire,
        run_count: 0,
        consecutive_failures: 0,
        state: serde_json::json!({}),
        created_at: now,
        updated_at: now,
    };

    db.create_routine(&routine).await?;

    println!("Created routine '{}'", name);
    println!("  ID:        {}", routine.id);
    println!("  Schedule:  {}", schedule);
    if let Some(tz) = timezone {
        println!("  Timezone:  {}", tz);
    }
    if let Some(nf) = next_fire {
        println!("  Next fire: {}", format_relative(nf));
    }
    Ok(())
}

// ── Edit ────────────────────────────────────────────────────

#[allow(clippy::too_many_arguments)]
async fn edit(
    db: &Arc<dyn Database>,
    user_id: &str,
    name: &str,
    schedule: Option<&str>,
    prompt: Option<&str>,
    description: Option<&str>,
    timezone: Option<&str>,
    cooldown: Option<u64>,
) -> anyhow::Result<()> {
    let mut routine = require_routine(db, user_id, name).await?;
    validate_timezone_arg(timezone)?;

    let mut changed = false;

    // Update schedule if provided (only valid for cron routines).
    if let Some(new_schedule) = schedule {
        let tz = timezone.or(match &routine.trigger {
            Trigger::Cron { timezone, .. } => timezone.as_deref(),
            _ => None,
        });
        let next_fire = next_cron_fire(new_schedule, tz)
            .map_err(|e| anyhow::anyhow!("Invalid cron schedule: {e}"))?;
        routine.trigger = Trigger::Cron {
            schedule: new_schedule.to_string(),
            timezone: tz.map(String::from),
        };
        routine.next_fire_at = next_fire;
        changed = true;
    } else if let Some(tz) = timezone {
        // Update only timezone, recompute next fire with existing schedule.
        if let Trigger::Cron { ref schedule, .. } = routine.trigger {
            let next_fire = next_cron_fire(schedule, Some(tz))
                .map_err(|e| anyhow::anyhow!("Invalid cron schedule: {e}"))?;
            routine.trigger = Trigger::Cron {
                schedule: schedule.clone(),
                timezone: Some(tz.to_string()),
            };
            routine.next_fire_at = next_fire;
            changed = true;
        } else {
            anyhow::bail!("Cannot set timezone on non-cron trigger");
        }
    }

    if let Some(new_prompt) = prompt {
        match &mut routine.action {
            RoutineAction::Lightweight { prompt: p, .. } => {
                *p = new_prompt.to_string();
                changed = true;
            }
            RoutineAction::FullJob { description: d, .. } => {
                *d = new_prompt.to_string();
                changed = true;
            }
        }
    }

    if let Some(new_desc) = description {
        routine.description = new_desc.to_string();
        changed = true;
    }

    if let Some(cd) = cooldown {
        routine.guardrails.cooldown = std::time::Duration::from_secs(cd);
        changed = true;
    }

    if !changed {
        println!("No changes specified.");
        return Ok(());
    }

    routine.updated_at = Utc::now();
    db.update_routine(&routine).await?;
    println!("Updated routine '{}'", name);
    Ok(())
}

// ── Enable / Disable ────────────────────────────────────────

async fn set_enabled(
    db: &Arc<dyn Database>,
    user_id: &str,
    name: &str,
    enabled: bool,
) -> anyhow::Result<()> {
    let mut routine = require_routine(db, user_id, name).await?;

    if routine.enabled == enabled {
        println!(
            "Routine '{}' is already {}",
            name,
            if enabled { "enabled" } else { "disabled" }
        );
        return Ok(());
    }

    routine.enabled = enabled;

    // Recompute next fire when enabling a cron routine.
    if enabled
        && let Trigger::Cron {
            ref schedule,
            ref timezone,
        } = routine.trigger
    {
        routine.next_fire_at = next_cron_fire(schedule, timezone.as_deref())
            .map_err(|e| anyhow::anyhow!("Failed to compute next fire for stored schedule: {e}"))?;
    }

    routine.updated_at = Utc::now();
    db.update_routine(&routine).await?;
    println!(
        "{} routine '{}'",
        if enabled { "Enabled" } else { "Disabled" },
        name
    );
    Ok(())
}

// ── Delete ──────────────────────────────────────────────────

async fn delete(
    db: &Arc<dyn Database>,
    user_id: &str,
    name: &str,
    skip_confirm: bool,
) -> anyhow::Result<()> {
    let routine = require_routine(db, user_id, name).await?;

    if !skip_confirm {
        println!("Routine: {}", routine.name);
        println!("      ID: {}", routine.id);
        println!(" Trigger: {}", routine.trigger.type_tag());
        if let Trigger::Cron { ref schedule, .. } = routine.trigger {
            println!("Schedule: {}", schedule);
        }
        println!("   Runs: {}", routine.run_count);
        print!("\nDelete this routine? [y/N] ");
        std::io::Write::flush(&mut std::io::stdout())?;

        let mut input = String::new();
        std::io::stdin().read_line(&mut input)?;
        if !matches!(input.trim().to_lowercase().as_str(), "y" | "yes") {
            println!("Cancelled.");
            return Ok(());
        }
    }

    let deleted = db.delete_routine(routine.id).await?;
    if deleted {
        println!("Deleted routine '{}'", name);
    } else {
        anyhow::bail!("Failed to delete routine '{}'", name);
    }
    Ok(())
}

// ── History ─────────────────────────────────────────────────

async fn history(
    db: &Arc<dyn Database>,
    user_id: &str,
    name: &str,
    limit: i64,
    json: bool,
) -> anyhow::Result<()> {
    let routine = require_routine(db, user_id, name).await?;

    let limit = limit.clamp(1, 50);
    let runs = db.list_routine_runs(routine.id, limit).await?;

    if json {
        let items: Vec<serde_json::Value> = runs
            .iter()
            .map(|run| {
                serde_json::json!({
                    "id": run.id.to_string(),
                    "status": run.status.to_string(),
                    "started_at": run.started_at,
                    "completed_at": run.completed_at,
                    "result_summary": run.result_summary,
                    "tokens_used": run.tokens_used,
                })
            })
            .collect();
        println!("{}", serde_json::to_string_pretty(&items)?);
        return Ok(());
    }

    if runs.is_empty() {
        println!("No runs found for routine '{}'", name);
        return Ok(());
    }

    println!("Run history for '{}' (last {}):\n", name, runs.len());

    println!(
        "{:<36}  {:<8}  {:<20}  {:<12}  SUMMARY",
        "RUN ID", "STATUS", "STARTED", "DURATION"
    );
    println!("{}", "-".repeat(100));

    for run in &runs {
        let duration = run
            .completed_at
            .map(|end| {
                let secs = (end - run.started_at).num_seconds();
                if secs < 60 {
                    format!("{}s", secs)
                } else {
                    format!("{}m{}s", secs / 60, secs % 60)
                }
            })
            .unwrap_or_else(|| "running".to_string());

        let summary = run
            .result_summary
            .as_deref()
            .map(|s| truncate(s, 40))
            .unwrap_or_else(|| "-".to_string());

        println!(
            "{:<36}  {:<8}  {:<20}  {:<12}  {}",
            run.id,
            run.status,
            run.started_at.format("%Y-%m-%d %H:%M:%S"),
            duration,
            summary,
        );
    }

    println!("\n{} run(s) shown", runs.len());
    Ok(())
}

// ── Shared lookup ────────────────────────────────────────────

/// Look up a routine by name.
async fn require_routine(
    db: &Arc<dyn Database>,
    user_id: &str,
    name: &str,
) -> anyhow::Result<Routine> {
    db.get_routine_by_name(user_id, name)
        .await?
        .ok_or_else(|| anyhow::anyhow!("Routine '{}' not found", name))
}

fn validate_timezone_arg(timezone: Option<&str>) -> anyhow::Result<()> {
    if let Some(tz) = timezone
        && crate::timezone::parse_timezone(tz).is_none()
    {
        anyhow::bail!("Invalid timezone: '{tz}' is not a valid IANA timezone");
    }
    Ok(())
}

// ── Helpers ─────────────────────────────────────────────────

/// Format a datetime relative to now (e.g. "in 2h", "3m ago").
fn format_relative(dt: DateTime<Utc>) -> String {
    let now = Utc::now();
    let diff = dt.signed_duration_since(now);
    let secs = diff.num_seconds();

    if secs.abs() < 60 {
        if secs >= 0 {
            "in <1m".to_string()
        } else {
            "<1m ago".to_string()
        }
    } else if secs.abs() < 3600 {
        let mins = secs.abs() / 60;
        if secs >= 0 {
            format!("in {}m", mins)
        } else {
            format!("{}m ago", mins)
        }
    } else if secs.abs() < 86400 {
        let hours = secs.abs() / 3600;
        if secs >= 0 {
            format!("in {}h", hours)
        } else {
            format!("{}h ago", hours)
        }
    } else {
        let days = secs.abs() / 86400;
        if secs >= 0 {
            format!("in {}d", days)
        } else {
            format!("{}d ago", days)
        }
    }
}

/// Truncate a string to a maximum character length.
fn truncate(s: &str, max_chars: usize) -> String {
    if s.chars().count() <= max_chars {
        s.to_string()
    } else {
        let truncated: String = s.chars().take(max_chars.saturating_sub(2)).collect();
        format!("{}..", truncated)
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn format_relative_future() {
        let future = Utc::now() + chrono::Duration::hours(2);
        let result = format_relative(future);
        assert!(
            result.starts_with("in "),
            "expected 'in ...' for future time, got: {result}"
        );
    }

    #[test]
    fn format_relative_past() {
        let past = Utc::now() - chrono::Duration::minutes(30);
        let result = format_relative(past);
        assert!(
            result.ends_with(" ago"),
            "expected '... ago' for past time, got: {result}"
        );
    }

    #[test]
    fn format_relative_days() {
        let far_future = Utc::now() + chrono::Duration::days(3);
        let result = format_relative(far_future);
        assert!(result.contains('d'), "expected days in: {result}");
    }

    #[test]
    fn truncate_short_string() {
        assert_eq!(truncate("hello", 10), "hello");
    }

    #[test]
    fn truncate_long_string() {
        let result = truncate("hello world", 7);
        assert_eq!(result, "hello..");
    }

    #[test]
    fn truncate_multibyte_safe() {
        // Ensure no panic on multi-byte characters.
        let cjk = "你好世界测试";
        let result = truncate(cjk, 4);
        assert!(result.ends_with(".."), "got: {result}");
        // Must be valid UTF-8 (would have panicked otherwise).
        assert!(result.is_char_boundary(result.len()));
    }
}
