//! Project-root discovery, subsystem initialisation (log, identity, DB, CRDT),
//! and CRDT-sync configuration.

use crate::config;
use crate::crdt_state;
use crate::crdt_sync;
use crate::db;
use crate::io::fs::find_story_kit_root;
use crate::log_buffer;
use crate::node_identity;
use crate::state::SessionState;
use crate::store::JsonFileStore;
use crate::worktree;
use std::path::{Path, PathBuf};
use std::sync::Arc;

/// Open (or scaffold) the project root according to the CLI flags and CWD.
///
/// Handles `--init`, an explicit path argument, and the default auto-detect
/// behaviour.  Modifies `app_state.project_root` as a side effect.
pub(crate) async fn open_project_root(
    is_init: bool,
    explicit_path: Option<PathBuf>,
    cwd: &Path,
    app_state: &Arc<SessionState>,
    store: &Arc<JsonFileStore>,
    port: u16,
) {
    if is_init {
        let init_root = explicit_path.unwrap_or_else(|| cwd.to_path_buf());
        if !init_root.exists() {
            std::fs::create_dir_all(&init_root).unwrap_or_else(|e| {
                eprintln!(
                    "error: cannot create directory {}: {e}",
                    init_root.display()
                );
                std::process::exit(1);
            });
        }
        match crate::io::fs::open_project(
            init_root.to_string_lossy().to_string(),
            app_state,
            store.as_ref(),
            port,
        )
        .await
        {
            Ok(_) => {
                if let Some(root) = app_state.project_root.lock().unwrap().as_ref() {
                    config::ProjectConfig::load(root)
                        .unwrap_or_else(|e| panic!("Invalid project.toml: {e}"));
                    crate::io::wizard::WizardState::init_if_missing(root);
                }
            }
            Err(e) => {
                eprintln!("error: {e}");
                std::process::exit(1);
            }
        }
    } else if let Some(explicit_root) = explicit_path {
        match crate::io::fs::open_project(
            explicit_root.to_string_lossy().to_string(),
            app_state,
            store.as_ref(),
            port,
        )
        .await
        {
            Ok(_) => {
                if let Some(root) = app_state.project_root.lock().unwrap().as_ref() {
                    config::ProjectConfig::load(root)
                        .unwrap_or_else(|e| panic!("Invalid project.toml: {e}"));
                }
            }
            Err(e) => {
                eprintln!("error: {e}");
                std::process::exit(1);
            }
        }
    } else if let Some(project_root) = find_story_kit_root(cwd) {
        crate::io::fs::open_project(
            project_root.to_string_lossy().to_string(),
            app_state,
            store.as_ref(),
            port,
        )
        .await
        .unwrap_or_else(|e| {
            crate::slog!("Warning: failed to auto-open project at {project_root:?}: {e}");
            project_root.to_string_lossy().to_string()
        });

        config::ProjectConfig::load(&project_root)
            .unwrap_or_else(|e| panic!("Invalid project.toml: {e}"));
    } else {
        crate::io::fs::open_project(
            cwd.to_string_lossy().to_string(),
            app_state,
            store.as_ref(),
            port,
        )
        .await
        .unwrap_or_else(|e| {
            crate::slog!("Warning: failed to scaffold project at {cwd:?}: {e}");
            cwd.to_string_lossy().to_string()
        });
    }
}

/// Set up the server log file, node identity keypair, pipeline DB, and CRDT state.
pub(crate) async fn init_subsystems(app_state: &Arc<SessionState>, cwd: &Path) {
    // Enable persistent server log file now that the project root is known.
    if let Some(ref root) = *app_state.project_root.lock().unwrap() {
        let log_dir = root.join(".huskies").join("logs");
        let _ = std::fs::create_dir_all(&log_dir);
        log_buffer::global().set_log_file(log_dir.join("server.log"));
    }

    // Initialise the node's Ed25519 identity keypair (file-based, mode 0600).
    // The key is stored at .huskies/node_identity.key and persisted across restarts.
    {
        let key_path = app_state
            .project_root
            .lock()
            .unwrap()
            .as_ref()
            .map(|root| root.join(".huskies").join("node_identity.key"))
            .unwrap_or_else(|| cwd.join(".huskies").join("node_identity.key"));
        if let Err(e) = node_identity::init_identity(&key_path) {
            crate::slog!("[identity] Failed to initialise node identity keypair: {e}");
        } else if let Some(id) = node_identity::get_identity() {
            crate::slog!("[identity] Node ID: {}", id.node_id);
        }
    }

    // Initialise the SQLite pipeline shadow-write database and CRDT state layer.
    // Clone the path out before the await so we don't hold the MutexGuard across
    // an await point.
    let pipeline_db_path = app_state
        .project_root
        .lock()
        .unwrap()
        .as_ref()
        .map(|root| root.join(".huskies").join("pipeline.db"));

    if let Some(ref db_path) = pipeline_db_path {
        if let Err(e) = db::init(db_path).await {
            crate::slog!("[db] Failed to initialise pipeline.db: {e}");
        }
        if let Err(e) = crdt_state::init(db_path).await {
            crate::slog!("[crdt] Failed to initialise CRDT state layer: {e}");
        } else {
            crdt_state::migrate_names_from_slugs();
            let id_migrations = crdt_state::migrate_story_ids_to_numeric();
            if !id_migrations.is_empty()
                && let Some(project_root) = db_path.parent().and_then(|p| p.parent())
            {
                worktree::migrate_slug_paths(project_root, &id_migrations);
            }
            // Story 865: one-shot strip of legacy YAML front-matter from
            // every stored body. Idempotent — bodies without `---` are
            // skipped on subsequent runs.
            db::yaml_migration::run();
        }
    }
}

/// Wire up CRDT sync: trusted keys, token auth, and the rendezvous client.
///
/// In agent mode the rendezvous URL comes from the CLI; otherwise it is read
/// from `project.toml`.
pub(crate) fn configure_crdt_sync(
    app_state: &Arc<SessionState>,
    is_agent: bool,
    agent_rendezvous: Option<String>,
    crdt_join_token: Option<String>,
) {
    let sync_config = if is_agent {
        agent_rendezvous
            .clone()
            .map(|url| (url, Vec::new(), false, Vec::new()))
    } else {
        app_state
            .project_root
            .lock()
            .unwrap()
            .as_ref()
            .and_then(|root| config::ProjectConfig::load(root).ok())
            .and_then(|cfg| {
                cfg.rendezvous.map(|url| {
                    (
                        url,
                        cfg.trusted_keys,
                        cfg.crdt_require_token,
                        cfg.crdt_tokens,
                    )
                })
            })
    };

    if let Some((rendezvous_url, trusted_keys, require_token, crdt_tokens)) = sync_config {
        crdt_sync::init_trusted_keys(trusted_keys);
        crdt_sync::init_token_auth(require_token, crdt_tokens);
        crdt_sync::spawn_rendezvous_client(rendezvous_url, crdt_join_token);
    } else {
        let (keys, require_token, crdt_tokens) = app_state
            .project_root
            .lock()
            .unwrap()
            .as_ref()
            .and_then(|root| config::ProjectConfig::load(root).ok())
            .map(|cfg| (cfg.trusted_keys, cfg.crdt_require_token, cfg.crdt_tokens))
            .unwrap_or_default();
        crdt_sync::init_trusted_keys(keys);
        crdt_sync::init_token_auth(require_token, crdt_tokens);
    }
}