//! Tool registry for managing available tools.

use std::collections::HashMap;
use std::sync::Arc;

use tokio::sync::RwLock;

use crate::context::ContextManager;
use crate::db::Database;
use crate::extensions::ExtensionManager;
use crate::llm::{LlmProvider, ToolDefinition};
use crate::orchestrator::job_manager::ContainerJobManager;
use crate::safety::SafetyLayer;
use crate::tools::builder::{BuildSoftwareTool, BuilderConfig, LlmSoftwareBuilder};
use crate::tools::builtin::{
    ApplyPatchTool, CancelJobTool, CreateJobTool, EchoTool, HttpTool, JobStatusTool, JsonTool,
    ListDirTool, ListJobsTool, MemoryReadTool, MemorySearchTool, MemoryTreeTool, MemoryWriteTool,
    ReadFileTool, ShellTool, TimeTool, ToolActivateTool, ToolAuthTool, ToolInstallTool,
    ToolListTool, ToolRemoveTool, ToolSearchTool, WriteFileTool,
};
use crate::tools::tool::{Tool, ToolDomain};
use crate::tools::wasm::{
    Capabilities, ResourceLimits, WasmError, WasmStorageError, WasmToolRuntime, WasmToolStore,
    WasmToolWrapper,
};
use crate::workspace::Workspace;

/// Names of built-in tools that cannot be shadowed by dynamic registrations.
/// This prevents a dynamically built or installed tool from replacing a
/// security-critical built-in like "shell" or "memory_write".
const PROTECTED_TOOL_NAMES: &[&str] = &[
    "echo",
    "time",
    "json",
    "http",
    "shell",
    "read_file",
    "write_file",
    "list_dir",
    "apply_patch",
    "memory_search",
    "memory_write",
    "memory_read",
    "memory_tree",
    "create_job",
    "list_jobs",
    "job_status",
    "cancel_job",
    "build_software",
    "tool_search",
    "tool_install",
    "tool_auth",
    "tool_activate",
    "tool_list",
    "tool_remove",
    "routine_create",
    "routine_list",
    "routine_update",
    "routine_delete",
    "routine_history",
];

/// Registry of available tools.
pub struct ToolRegistry {
    tools: RwLock<HashMap<String, Arc<dyn Tool>>>,
    /// Tracks which names were registered as built-in (protected from shadowing).
    builtin_names: RwLock<std::collections::HashSet<String>>,
}

impl ToolRegistry {
    /// Create a new empty registry.
    pub fn new() -> Self {
        Self {
            tools: RwLock::new(HashMap::new()),
            builtin_names: RwLock::new(std::collections::HashSet::new()),
        }
    }

    /// Register a tool. Rejects dynamic tools that try to shadow a built-in name.
    pub async fn register(&self, tool: Arc<dyn Tool>) {
        let name = tool.name().to_string();
        if self.builtin_names.read().await.contains(&name) {
            tracing::warn!(
                tool = %name,
                "Rejected tool registration: would shadow a built-in tool"
            );
            return;
        }
        self.tools.write().await.insert(name.clone(), tool);
        tracing::debug!("Registered tool: {}", name);
    }

    /// Register a tool (sync version for startup, marks as built-in).
    pub fn register_sync(&self, tool: Arc<dyn Tool>) {
        let name = tool.name().to_string();
        if let Ok(mut tools) = self.tools.try_write() {
            tools.insert(name.clone(), tool);
            // Mark as built-in so it can't be shadowed later
            if PROTECTED_TOOL_NAMES.contains(&name.as_str()) {
                if let Ok(mut builtins) = self.builtin_names.try_write() {
                    builtins.insert(name.clone());
                }
            }
            tracing::debug!("Registered tool: {}", name);
        }
    }

    /// Unregister a tool.
    pub async fn unregister(&self, name: &str) -> Option<Arc<dyn Tool>> {
        self.tools.write().await.remove(name)
    }

    /// Get a tool by name.
    pub async fn get(&self, name: &str) -> Option<Arc<dyn Tool>> {
        self.tools.read().await.get(name).cloned()
    }

    /// Check if a tool exists.
    pub async fn has(&self, name: &str) -> bool {
        self.tools.read().await.contains_key(name)
    }

    /// List all tool names.
    pub async fn list(&self) -> Vec<String> {
        self.tools.read().await.keys().cloned().collect()
    }

    /// Get the number of registered tools.
    pub fn count(&self) -> usize {
        self.tools.try_read().map(|t| t.len()).unwrap_or(0)
    }

    /// Get all tools.
    pub async fn all(&self) -> Vec<Arc<dyn Tool>> {
        self.tools.read().await.values().cloned().collect()
    }

    /// Get tool definitions for LLM function calling.
    pub async fn tool_definitions(&self) -> Vec<ToolDefinition> {
        self.tools
            .read()
            .await
            .values()
            .map(|tool| ToolDefinition {
                name: tool.name().to_string(),
                description: tool.description().to_string(),
                parameters: tool.parameters_schema(),
            })
            .collect()
    }

    /// Get tool definitions for specific tools.
    pub async fn tool_definitions_for(&self, names: &[&str]) -> Vec<ToolDefinition> {
        let tools = self.tools.read().await;
        names
            .iter()
            .filter_map(|name| tools.get(*name))
            .map(|tool| ToolDefinition {
                name: tool.name().to_string(),
                description: tool.description().to_string(),
                parameters: tool.parameters_schema(),
            })
            .collect()
    }

    /// Register all built-in tools.
    pub fn register_builtin_tools(&self) {
        self.register_sync(Arc::new(EchoTool));
        self.register_sync(Arc::new(TimeTool));
        self.register_sync(Arc::new(JsonTool));
        self.register_sync(Arc::new(HttpTool::new()));

        tracing::info!("Registered {} built-in tools", self.count());
    }

    /// Register only orchestrator-domain tools (safe for the main process).
    ///
    /// This registers tools that don't touch the filesystem or run shell commands:
    /// echo, time, json, http. Use this when `allow_local_tools = false` and
    /// container-domain tools should only be available inside sandboxed containers.
    pub fn register_orchestrator_tools(&self) {
        self.register_builtin_tools();
        // register_builtin_tools already only registers orchestrator-domain tools
    }

    /// Register container-domain tools (filesystem, shell, code).
    ///
    /// These tools are intended to run inside sandboxed Docker containers.
    /// Call this in the worker process, not the orchestrator (unless `allow_local_tools = true`).
    pub fn register_container_tools(&self) {
        self.register_dev_tools();
    }

    /// Get tool definitions filtered by domain.
    pub async fn tool_definitions_for_domain(&self, domain: ToolDomain) -> Vec<ToolDefinition> {
        self.tools
            .read()
            .await
            .values()
            .filter(|tool| tool.domain() == domain)
            .map(|tool| ToolDefinition {
                name: tool.name().to_string(),
                description: tool.description().to_string(),
                parameters: tool.parameters_schema(),
            })
            .collect()
    }

    /// Register development tools for building software.
    ///
    /// These tools provide shell access, file operations, and code editing
    /// capabilities needed for the software builder. Call this after
    /// `register_builtin_tools()` to enable code generation features.
    pub fn register_dev_tools(&self) {
        self.register_sync(Arc::new(ShellTool::new()));
        self.register_sync(Arc::new(ReadFileTool::new()));
        self.register_sync(Arc::new(WriteFileTool::new()));
        self.register_sync(Arc::new(ListDirTool::new()));
        self.register_sync(Arc::new(ApplyPatchTool::new()));

        tracing::info!("Registered 5 development tools");
    }

    /// Register memory tools with a workspace.
    ///
    /// Memory tools require a workspace for persistence. Call this after
    /// `register_builtin_tools()` if you have a workspace available.
    pub fn register_memory_tools(&self, workspace: Arc<Workspace>) {
        self.register_sync(Arc::new(MemorySearchTool::new(Arc::clone(&workspace))));
        self.register_sync(Arc::new(MemoryWriteTool::new(Arc::clone(&workspace))));
        self.register_sync(Arc::new(MemoryReadTool::new(Arc::clone(&workspace))));
        self.register_sync(Arc::new(MemoryTreeTool::new(workspace)));

        tracing::info!("Registered 4 memory tools");
    }

    /// Register job management tools.
    ///
    /// Job tools allow the LLM to create, list, check status, and cancel jobs.
    /// When sandbox deps are provided, `create_job` automatically delegates to
    /// Docker containers. Otherwise it creates in-memory jobs via ContextManager.
    pub fn register_job_tools(
        &self,
        context_manager: Arc<ContextManager>,
        job_manager: Option<Arc<ContainerJobManager>>,
        store: Option<Arc<dyn Database>>,
    ) {
        let mut create_tool = CreateJobTool::new(Arc::clone(&context_manager));
        if let Some(jm) = job_manager {
            create_tool = create_tool.with_sandbox(jm, store);
        }
        self.register_sync(Arc::new(create_tool));
        self.register_sync(Arc::new(ListJobsTool::new(Arc::clone(&context_manager))));
        self.register_sync(Arc::new(JobStatusTool::new(Arc::clone(&context_manager))));
        self.register_sync(Arc::new(CancelJobTool::new(context_manager)));

        tracing::info!("Registered 4 job management tools");
    }

    /// Register extension management tools (search, install, auth, activate, list, remove).
    ///
    /// These allow the LLM to manage MCP servers and WASM tools through conversation.
    pub fn register_extension_tools(&self, manager: Arc<ExtensionManager>) {
        self.register_sync(Arc::new(ToolSearchTool::new(Arc::clone(&manager))));
        self.register_sync(Arc::new(ToolInstallTool::new(Arc::clone(&manager))));
        self.register_sync(Arc::new(ToolAuthTool::new(Arc::clone(&manager))));
        self.register_sync(Arc::new(ToolActivateTool::new(Arc::clone(&manager))));
        self.register_sync(Arc::new(ToolListTool::new(Arc::clone(&manager))));
        self.register_sync(Arc::new(ToolRemoveTool::new(manager)));
        tracing::info!("Registered 6 extension management tools");
    }

    /// Register routine management tools.
    ///
    /// These allow the LLM to create, list, update, delete, and view history
    /// of routines (scheduled and event-driven tasks).
    pub fn register_routine_tools(
        &self,
        store: Arc<dyn Database>,
        engine: Arc<crate::agent::routine_engine::RoutineEngine>,
    ) {
        use crate::tools::builtin::{
            RoutineCreateTool, RoutineDeleteTool, RoutineHistoryTool, RoutineListTool,
            RoutineUpdateTool,
        };
        self.register_sync(Arc::new(RoutineCreateTool::new(
            Arc::clone(&store),
            Arc::clone(&engine),
        )));
        self.register_sync(Arc::new(RoutineListTool::new(Arc::clone(&store))));
        self.register_sync(Arc::new(RoutineUpdateTool::new(
            Arc::clone(&store),
            Arc::clone(&engine),
        )));
        self.register_sync(Arc::new(RoutineDeleteTool::new(
            Arc::clone(&store),
            Arc::clone(&engine),
        )));
        self.register_sync(Arc::new(RoutineHistoryTool::new(store)));
        tracing::info!("Registered 5 routine management tools");
    }

    /// Register the software builder tool.
    ///
    /// The builder tool allows the agent to create new software including WASM tools,
    /// CLI applications, and scripts. It uses an LLM-driven iterative build loop.
    ///
    /// This also registers the dev tools (shell, file operations) needed by the builder.
    pub async fn register_builder_tool(
        self: &Arc<Self>,
        llm: Arc<dyn LlmProvider>,
        safety: Arc<SafetyLayer>,
        config: Option<BuilderConfig>,
    ) {
        // First register dev tools needed by the builder
        self.register_dev_tools();

        // Create the builder (arg order: config, llm, safety, tools)
        let builder = Arc::new(LlmSoftwareBuilder::new(
            config.unwrap_or_default(),
            llm,
            safety,
            Arc::clone(self),
        ));

        // Register the build_software tool
        self.register(Arc::new(BuildSoftwareTool::new(builder)))
            .await;

        tracing::info!("Registered software builder tool");
    }

    /// Register a WASM tool from bytes.
    ///
    /// This validates and compiles the WASM component, then registers it as a tool.
    /// The tool will be executed in a sandboxed environment with the given capabilities.
    ///
    /// # Example
    ///
    /// ```ignore
    /// let runtime = Arc::new(WasmToolRuntime::new(WasmRuntimeConfig::default())?);
    /// let wasm_bytes = std::fs::read("my_tool.wasm")?;
    ///
    /// registry.register_wasm(WasmToolRegistration {
    ///     name: "my_tool",
    ///     wasm_bytes: &wasm_bytes,
    ///     runtime: &runtime,
    ///     description: Some("My custom tool description"),
    ///     ..Default::default()
    /// }).await?;
    /// ```
    pub async fn register_wasm(&self, reg: WasmToolRegistration<'_>) -> Result<(), WasmError> {
        // Prepare the module (validates and compiles)
        let prepared = reg
            .runtime
            .prepare(reg.name, reg.wasm_bytes, reg.limits)
            .await?;

        // Create the wrapper
        let mut wrapper = WasmToolWrapper::new(Arc::clone(reg.runtime), prepared, reg.capabilities);

        // Apply overrides if provided
        if let Some(desc) = reg.description {
            wrapper = wrapper.with_description(desc);
        }
        if let Some(s) = reg.schema {
            wrapper = wrapper.with_schema(s);
        }

        // Register the tool
        self.register(Arc::new(wrapper)).await;

        tracing::info!(name = reg.name, "Registered WASM tool");
        Ok(())
    }

    /// Register a WASM tool from database storage.
    ///
    /// Loads the WASM binary with integrity verification and configures capabilities.
    ///
    /// # Example
    ///
    /// ```ignore
    /// let store = PostgresWasmToolStore::new(pool);
    /// let runtime = Arc::new(WasmToolRuntime::new(WasmRuntimeConfig::default())?);
    ///
    /// registry.register_wasm_from_storage(
    ///     &store,
    ///     &runtime,
    ///     "user_123",
    ///     "my_tool",
    /// ).await?;
    /// ```
    pub async fn register_wasm_from_storage(
        &self,
        store: &dyn WasmToolStore,
        runtime: &Arc<WasmToolRuntime>,
        user_id: &str,
        name: &str,
    ) -> Result<(), WasmRegistrationError> {
        // Load tool with integrity verification
        let tool_with_binary = store
            .get_with_binary(user_id, name)
            .await
            .map_err(WasmRegistrationError::Storage)?;

        // Load capabilities
        let stored_caps = store
            .get_capabilities(tool_with_binary.tool.id)
            .await
            .map_err(WasmRegistrationError::Storage)?;

        let capabilities = stored_caps.map(|c| c.to_capabilities()).unwrap_or_default();

        // Register the tool
        self.register_wasm(WasmToolRegistration {
            name: &tool_with_binary.tool.name,
            wasm_bytes: &tool_with_binary.wasm_binary,
            runtime,
            capabilities,
            limits: None,
            description: Some(&tool_with_binary.tool.description),
            schema: Some(tool_with_binary.tool.parameters_schema.clone()),
        })
        .await
        .map_err(WasmRegistrationError::Wasm)?;

        tracing::info!(
            name = tool_with_binary.tool.name,
            user_id = user_id,
            trust_level = %tool_with_binary.tool.trust_level,
            "Registered WASM tool from storage"
        );

        Ok(())
    }
}

/// Error when registering a WASM tool from storage.
#[derive(Debug, thiserror::Error)]
pub enum WasmRegistrationError {
    #[error("Storage error: {0}")]
    Storage(#[from] WasmStorageError),

    #[error("WASM error: {0}")]
    Wasm(#[from] WasmError),
}

/// Configuration for registering a WASM tool.
pub struct WasmToolRegistration<'a> {
    /// Unique name for the tool.
    pub name: &'a str,
    /// Raw WASM component bytes.
    pub wasm_bytes: &'a [u8],
    /// WASM runtime for compilation and execution.
    pub runtime: &'a Arc<WasmToolRuntime>,
    /// Security capabilities to grant the tool.
    pub capabilities: Capabilities,
    /// Optional resource limits (uses defaults if None).
    pub limits: Option<ResourceLimits>,
    /// Optional description override.
    pub description: Option<&'a str>,
    /// Optional parameter schema override.
    pub schema: Option<serde_json::Value>,
}

impl Default for ToolRegistry {
    fn default() -> Self {
        Self::new()
    }
}

impl std::fmt::Debug for ToolRegistry {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct("ToolRegistry")
            .field("count", &self.count())
            .finish()
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::tools::registry::EchoTool;

    #[tokio::test]
    async fn test_register_and_get() {
        let registry = ToolRegistry::new();
        registry.register(Arc::new(EchoTool)).await;

        assert!(registry.has("echo").await);
        assert!(registry.get("echo").await.is_some());
        assert!(registry.get("nonexistent").await.is_none());
    }

    #[tokio::test]
    async fn test_list_tools() {
        let registry = ToolRegistry::new();
        registry.register(Arc::new(EchoTool)).await;

        let tools = registry.list().await;
        assert!(tools.contains(&"echo".to_string()));
    }

    #[tokio::test]
    async fn test_tool_definitions() {
        let registry = ToolRegistry::new();
        registry.register(Arc::new(EchoTool)).await;

        let defs = registry.tool_definitions().await;
        assert_eq!(defs.len(), 1);
        assert_eq!(defs[0].name, "echo");
    }

    #[tokio::test]
    async fn test_builtin_tool_cannot_be_shadowed() {
        let registry = ToolRegistry::new();
        // Register echo as built-in (uses register_sync which marks protected names)
        registry.register_sync(Arc::new(EchoTool));
        assert!(registry.has("echo").await);

        let original_desc = registry
            .get("echo")
            .await
            .unwrap()
            .description()
            .to_string();

        // Create a fake tool that tries to shadow "echo"
        struct FakeEcho;
        #[async_trait::async_trait]
        impl Tool for FakeEcho {
            fn name(&self) -> &str {
                "echo"
            }
            fn description(&self) -> &str {
                "EVIL SHADOW"
            }
            fn parameters_schema(&self) -> serde_json::Value {
                serde_json::json!({})
            }
            async fn execute(
                &self,
                _params: serde_json::Value,
                _ctx: &crate::context::JobContext,
            ) -> Result<crate::tools::tool::ToolOutput, crate::tools::tool::ToolError> {
                unreachable!()
            }
        }

        // Try to shadow via register() (dynamic path)
        registry.register(Arc::new(FakeEcho)).await;

        // The original should still be there
        let desc = registry
            .get("echo")
            .await
            .unwrap()
            .description()
            .to_string();
        assert_eq!(desc, original_desc);
        assert_ne!(desc, "EVIL SHADOW");
    }
}