mod agents;
mod config;
mod http;
mod io;
mod llm;
mod state;
mod store;
mod workflow;
mod worktree;

use crate::agents::AgentPool;
use crate::http::build_routes;
use crate::http::context::AppContext;
use crate::state::SessionState;
use crate::store::JsonFileStore;
use crate::workflow::WorkflowState;
use poem::Server;
use poem::listener::TcpListener;
use std::path::{Path, PathBuf};
use std::sync::Arc;
use tokio::sync::broadcast;

const DEFAULT_PORT: u16 = 3001;

fn parse_port(value: Option<String>) -> u16 {
    value
        .and_then(|v| v.parse::<u16>().ok())
        .unwrap_or(DEFAULT_PORT)
}

fn resolve_port() -> u16 {
    parse_port(std::env::var("STORYKIT_PORT").ok())
}

fn write_port_file(dir: &Path, port: u16) -> Option<PathBuf> {
    let path = dir.join(".story_kit_port");
    std::fs::write(&path, port.to_string()).ok()?;
    Some(path)
}

fn remove_port_file(path: &Path) {
    let _ = std::fs::remove_file(path);
}

/// Walk from `start` up through parent directories, returning the first
/// directory that contains a `.story_kit/` subdirectory, or `None`.
fn find_story_kit_root(start: &Path) -> Option<PathBuf> {
    let mut current = start.to_path_buf();
    loop {
        if current.join(".story_kit").is_dir() {
            return Some(current);
        }
        if !current.pop() {
            return None;
        }
    }
}

#[tokio::main]
async fn main() -> Result<(), std::io::Error> {
    let app_state = Arc::new(SessionState::default());
    let cwd = std::env::current_dir().unwrap_or_else(|_| PathBuf::from("."));
    let store = Arc::new(
        JsonFileStore::from_path(PathBuf::from("store.json")).map_err(std::io::Error::other)?,
    );

    // Auto-detect a .story_kit/ project in cwd or parent directories.
    if let Some(project_root) = find_story_kit_root(&cwd) {
        io::fs::open_project(
            project_root.to_string_lossy().to_string(),
            &app_state,
            store.as_ref(),
        )
        .await
        .unwrap_or_else(|e| {
            eprintln!("Warning: failed to auto-open project at {project_root:?}: {e}");
            project_root.to_string_lossy().to_string()
        });

        // Validate agent config for the detected project root.
        config::ProjectConfig::load(&project_root)
            .unwrap_or_else(|e| panic!("Invalid project.toml: {e}"));
    } else {
        // No .story_kit/ found — fall back to cwd so existing behaviour is preserved.
        *app_state.project_root.lock().unwrap() = Some(cwd.clone());
    }

    let workflow = Arc::new(std::sync::Mutex::new(WorkflowState::default()));
    let port = resolve_port();
    let agents = Arc::new(AgentPool::new(port));

    // Filesystem watcher: broadcast channel for work/ pipeline changes.
    let (watcher_tx, _) = broadcast::channel::<io::watcher::WatcherEvent>(1024);
    if let Some(ref root) = *app_state.project_root.lock().unwrap() {
        let work_dir = root.join(".story_kit").join("work");
        if work_dir.is_dir() {
            io::watcher::start_watcher(work_dir, root.clone(), watcher_tx.clone());
        }
    }

    let ctx = AppContext {
        state: app_state,
        store,
        workflow,
        agents,
        watcher_tx,
    };

    let app = build_routes(ctx);
    let addr = format!("127.0.0.1:{port}");

    println!(
        "\x1b[95;1m  ____  _             _    ___ _   \n / ___|| |_ ___  _ __| | _|_ _| |_ \n \\___ \\| __/ _ \\| '__| |/ /| || __|\n  ___) | || (_) | |  |   < | || |_ \n |____/ \\__\\___/|_|  |_|\\_\\___|\\__|\n\x1b[0m"
    );
    println!("STORYKIT_PORT={port}");
    println!("\x1b[96;1mFrontend:\x1b[0m \x1b[94mhttp://{addr}\x1b[0m");
    println!("\x1b[92;1mOpenAPI Docs:\x1b[0m \x1b[94mhttp://{addr}/docs\x1b[0m");

    let port_file = write_port_file(&cwd, port);

    let result = Server::new(TcpListener::bind(&addr)).run(app).await;

    if let Some(ref path) = port_file {
        remove_port_file(path);
    }

    result
}

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

    #[test]
    fn parse_port_defaults_to_3001() {
        assert_eq!(parse_port(None), 3001);
    }

    #[test]
    fn parse_port_reads_valid_value() {
        assert_eq!(parse_port(Some("4200".to_string())), 4200);
    }

    #[test]
    fn parse_port_ignores_invalid_value() {
        assert_eq!(parse_port(Some("not_a_number".to_string())), 3001);
    }

    #[test]
    #[should_panic(expected = "Invalid project.toml: Duplicate agent name")]
    fn panics_on_duplicate_agent_names() {
        let tmp = tempfile::tempdir().unwrap();
        let sk = tmp.path().join(".story_kit");
        std::fs::create_dir_all(&sk).unwrap();
        std::fs::write(
            sk.join("project.toml"),
            r#"
[[agent]]
name = "coder"

[[agent]]
name = "coder"
"#,
        )
        .unwrap();

        config::ProjectConfig::load(tmp.path())
            .unwrap_or_else(|e| panic!("Invalid project.toml: {e}"));
    }

    #[test]
    fn write_and_remove_port_file() {
        let tmp = tempfile::tempdir().unwrap();

        let path = write_port_file(tmp.path(), 4567).expect("should write port file");
        assert_eq!(std::fs::read_to_string(&path).unwrap(), "4567");

        remove_port_file(&path);
        assert!(!path.exists());
    }

    #[test]
    fn find_story_kit_root_returns_cwd_when_story_kit_in_cwd() {
        let tmp = tempfile::tempdir().unwrap();
        std::fs::create_dir_all(tmp.path().join(".story_kit")).unwrap();

        let result = find_story_kit_root(tmp.path());
        assert_eq!(result, Some(tmp.path().to_path_buf()));
    }

    #[test]
    fn find_story_kit_root_returns_parent_when_story_kit_in_parent() {
        let tmp = tempfile::tempdir().unwrap();
        std::fs::create_dir_all(tmp.path().join(".story_kit")).unwrap();
        let child = tmp.path().join("subdir").join("nested");
        std::fs::create_dir_all(&child).unwrap();

        let result = find_story_kit_root(&child);
        assert_eq!(result, Some(tmp.path().to_path_buf()));
    }

    #[test]
    fn find_story_kit_root_returns_none_when_no_story_kit() {
        let tmp = tempfile::tempdir().unwrap();
        // No .story_kit/ created

        let result = find_story_kit_root(tmp.path());
        assert_eq!(result, None);
    }

    #[test]
    fn find_story_kit_root_prefers_nearest_ancestor() {
        // If both cwd and a parent have .story_kit/, return cwd (nearest).
        let tmp = tempfile::tempdir().unwrap();
        std::fs::create_dir_all(tmp.path().join(".story_kit")).unwrap();
        let child = tmp.path().join("inner");
        std::fs::create_dir_all(child.join(".story_kit")).unwrap();

        let result = find_story_kit_root(&child);
        assert_eq!(result, Some(child));
    }
}