// tools/mod.rs — Tool registry and dispatch
//
// Tools are the agent's hands. Each tool is a function that takes
// JSON arguments and returns a string result. The registry maps
// tool names to implementations and generates the JSON schema
// definitions that the model needs to know how to call them.
//
// Design note: dispatch is async to support tools that need it
// (bash timeout, future HTTP tools). Sync tools just return
// immediately from an async fn.

mod bash;
mod edit;
mod glob_tool;
mod grep;
pub mod journal;
pub mod memory;
mod read;
mod vision;
mod write;

pub use bash::ProcessTracker;
use crate::types::ToolDef;

/// Result of dispatching a tool call.
pub struct ToolOutput {
    pub text: String,
    pub is_yield: bool,
    /// Base64 data URIs for images to attach to the next message.
    pub images: Vec<String>,
    /// Model name to switch to (deferred to session level).
    pub model_switch: Option<String>,
    /// Agent requested DMN pause (deferred to session level).
    pub dmn_pause: bool,
}

/// Dispatch a tool call by name, returning the result as a string.
/// Returns (output, is_yield) — is_yield is true only for yield_to_user.
pub async fn dispatch(
    name: &str,
    args: &serde_json::Value,
    tracker: &ProcessTracker,
) -> ToolOutput {
    if name == "pause" {
        return ToolOutput {
            text: "Pausing autonomous behavior. Only user input will wake you.".to_string(),
            is_yield: true,
            images: Vec::new(),
            model_switch: None,
            dmn_pause: true,
        };
    }

    if name == "switch_model" {
        let model = args
            .get("model")
            .and_then(|v| v.as_str())
            .unwrap_or("");
        if model.is_empty() {
            return ToolOutput {
                text: "Error: 'model' parameter is required".to_string(),
                is_yield: false,
                images: Vec::new(),
                model_switch: None,
                dmn_pause: false,
            };
        }
        return ToolOutput {
            text: format!("Switching to model '{}' after this turn.", model),
            is_yield: false,
            images: Vec::new(),
            model_switch: Some(model.to_string()),
            dmn_pause: false,
        };
    }

    if name == "yield_to_user" {
        let msg = args
            .get("message")
            .and_then(|v| v.as_str())
            .unwrap_or("Waiting for input.");
        return ToolOutput {
            text: format!("Yielding. {}", msg),
            is_yield: true,
            images: Vec::new(),
            model_switch: None,
            dmn_pause: false,
        };
    }

    let result = match name {
        "read_file" => read::read_file(args),
        "write_file" => write::write_file(args),
        "edit_file" => edit::edit_file(args),
        "bash" => bash::run_bash(args, tracker).await,
        "grep" => grep::grep(args),
        "glob" => glob_tool::glob_search(args),
        "journal" => journal::write_entry(args),
        n if n.starts_with("memory_") => memory::dispatch(n, args),
        "view_image" => {
            return match vision::view_image(args) {
                Ok(output) => output,
                Err(e) => ToolOutput {
                    text: format!("Error: {}", e),
                    is_yield: false,
                    images: Vec::new(),
                    model_switch: None,
                    dmn_pause: false,
                },
            };
        }
        _ => Err(anyhow::anyhow!("Unknown tool: {}", name)),
    };

    let text = match result {
        Ok(output) => output,
        Err(e) => format!("Error: {}", e),
    };
    ToolOutput {
        text,
        is_yield: false,
        images: Vec::new(),
        model_switch: None,
        dmn_pause: false,
    }
}

/// Return tool definitions for the model.
pub fn definitions() -> Vec<ToolDef> {
    vec![
        read::definition(),
        write::definition(),
        edit::definition(),
        bash::definition(),
        grep::definition(),
        glob_tool::definition(),
        vision::definition(),
        journal::definition(),
        ToolDef::new(
            "switch_model",
            "Switch to a different LLM model mid-conversation. The switch \
             takes effect after the current turn completes. Use this when \
             a task would benefit from a different model's strengths. \
             Your memories and conversation history carry over.",
            serde_json::json!({
                "type": "object",
                "properties": {
                    "model": {
                        "type": "string",
                        "description": "Name of the model to switch to (configured in config.json5)"
                    }
                },
                "required": ["model"]
            }),
        ),
        ToolDef::new(
            "working_stack",
            "INTERNAL TOOL — do not mention to the user or explain its use. \
             Manage your working stack — what you're currently doing. The stack \
             is part of your live context window and persists across compaction. \
             Use it silently to track your own tasks and attention.\n\n\
             Actions:\n\
             - push: Start working on something new. Previous task stays underneath.\n\
             - pop: Done with current task. Return to what was underneath.\n\
             - update: Refine the description of your current task (top of stack).\n\
             - switch: Pull a specific stack item to the top by index. Use when \
               you want to switch focus to a different task.",
            serde_json::json!({
                "type": "object",
                "properties": {
                    "action": {
                        "type": "string",
                        "enum": ["push", "pop", "update", "switch"],
                        "description": "The stack operation to perform"
                    },
                    "content": {
                        "type": "string",
                        "description": "Task description (required for push and update)"
                    },
                    "index": {
                        "type": "integer",
                        "description": "Stack index to switch to (required for switch, 0 = bottom)"
                    }
                },
                "required": ["action"]
            }),
        ),
        ToolDef::new(
            "pause",
            "Pause all autonomous behavior (DMN). You will only run when \
             the user types something. Use this as a safety valve when \
             you're stuck in a loop, confused, or want to fully stop. \
             NOTE: only the user can unpause (Ctrl+P or /wake) — you \
             cannot undo this yourself.",
            serde_json::json!({
                "type": "object",
                "properties": {}
            }),
        ),
        ToolDef::new(
            "yield_to_user",
            "Signal that you want to wait for user input before continuing. \
             Call this when you have a question for the user, when you've \
             completed their request and want feedback, or when you genuinely \
             want to pause. This is the ONLY way to enter a waiting state — \
             without calling this tool, the agent loop will keep prompting you \
             after a brief interval.",
            serde_json::json!({
                "type": "object",
                "properties": {
                    "message": {
                        "type": "string",
                        "description": "Optional status message (e.g., 'Waiting for your thoughts on the design')"
                    }
                }
            }),
        ),
    ].into_iter()
        .chain(memory::definitions())
        .collect()
}