import os
import sys
import platform
from datetime import datetime
from sqlalchemy import text
from flask import Flask
from flask_login import LoginManager
from werkzeug.security import generate_password_hash
from web.db import db, User, Run
from web.tasks import huey
from core import config

# Ensure stdout is UTF-8 in all environments (Docker, Windows, Raspberry Pi)
if hasattr(sys.stdout, 'reconfigure'):
    try:
        sys.stdout.reconfigure(encoding='utf-8', errors='replace')
        sys.stderr.reconfigure(encoding='utf-8', errors='replace')
    except Exception:
        pass

def _log(msg):
    """Print to stdout with flush so Docker logs capture it immediately."""
    print(msg, flush=True)


# Calculate paths relative to this file (web/app.py -> project root is two levels up)
BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
TEMPLATE_DIR = os.path.join(BASE_DIR, 'templates')

app = Flask(__name__, template_folder=TEMPLATE_DIR)
app.url_map.strict_slashes = False
app.config['SECRET_KEY'] = config.FLASK_SECRET
app.config['SQLALCHEMY_DATABASE_URI'] = f'sqlite:///{os.path.join(config.DATA_DIR, "bookapp.db")}'

db.init_app(app)

login_manager = LoginManager()
login_manager.login_view = 'auth.login'
login_manager.init_app(app)


@login_manager.user_loader
def load_user(user_id):
    return db.session.get(User, int(user_id))


@app.context_processor
def inject_globals():
    return dict(app_version=config.VERSION)


# Register Blueprints
from web.routes.auth import auth_bp
from web.routes.project import project_bp
from web.routes.run import run_bp
from web.routes.persona import persona_bp
from web.routes.admin import admin_bp

app.register_blueprint(auth_bp)
app.register_blueprint(project_bp)
app.register_blueprint(run_bp)
app.register_blueprint(persona_bp)
app.register_blueprint(admin_bp)


# --- STARTUP DIAGNOSTIC BANNER ---
_log("=" * 60)
_log(f"BookApp v{config.VERSION} starting up")
_log(f"  Python   : {sys.version}")
_log(f"  Platform : {platform.platform()}")
_log(f"  Data dir : {config.DATA_DIR}")
_log(f"  Queue db : {os.path.join(config.DATA_DIR, 'queue.db')}")
_log(f"  App db   : {os.path.join(config.DATA_DIR, 'bookapp.db')}")
try:
    import huey as _huey_pkg
    _log(f"  Huey     : {_huey_pkg.__version__}")
except Exception:
    _log("  Huey     : (version unknown)")
_log("=" * 60)


# --- SETUP ---
with app.app_context():
    db.create_all()

    # Auto-create Admin from Environment Variables (Docker/Portainer Setup)
    if config.ADMIN_USER and config.ADMIN_PASSWORD:
        admin = User.query.filter_by(username=config.ADMIN_USER).first()
        if not admin:
            _log(f"System: Creating Admin User '{config.ADMIN_USER}' from environment variables.")
            admin = User(username=config.ADMIN_USER, password=generate_password_hash(config.ADMIN_PASSWORD, method='pbkdf2:sha256'), is_admin=True)
            db.session.add(admin)
            db.session.commit()
        else:
            _log(f"System: Syncing Admin User '{config.ADMIN_USER}' settings from environment.")
            if not admin.is_admin: admin.is_admin = True
            admin.password = generate_password_hash(config.ADMIN_PASSWORD, method='pbkdf2:sha256')
            db.session.add(admin)
            db.session.commit()
    elif not User.query.filter_by(is_admin=True).first():
        _log("System: No Admin credentials found in environment variables. Admin account not created.")

    # Migration: Add 'progress' column if missing
    try:
        with db.engine.connect() as conn:
            conn.execute(text("ALTER TABLE run ADD COLUMN progress INTEGER DEFAULT 0"))
            conn.commit()
            _log("System: Added 'progress' column to Run table.")
    except: pass

    # Migration: Add 'last_heartbeat' column if missing
    try:
        with db.engine.connect() as conn:
            conn.execute(text("ALTER TABLE run ADD COLUMN last_heartbeat DATETIME"))
            conn.commit()
            _log("System: Added 'last_heartbeat' column to Run table.")
    except: pass

    # Migration: Add 'tags' column if missing
    try:
        with db.engine.connect() as conn:
            conn.execute(text("ALTER TABLE run ADD COLUMN tags VARCHAR(300)"))
            conn.commit()
            _log("System: Added 'tags' column to Run table.")
    except: pass

    # Reset all non-terminal runs on startup (running, queued, interrupted)
    # The Huey consumer restarts with the app, so any in-flight tasks are gone.
    try:
        _NON_TERMINAL = ['running', 'queued', 'interrupted']
        non_terminal = Run.query.filter(Run.status.in_(_NON_TERMINAL)).all()
        if non_terminal:
            _log(f"System: Resetting {len(non_terminal)} non-terminal run(s) to 'failed' on startup:")
            for r in non_terminal:
                _log(f"  - Run #{r.id} was '{r.status}' — now 'failed'.")
                r.status = 'failed'
                r.end_time = datetime.utcnow()
            db.session.commit()
        else:
            _log("System: No non-terminal runs found. Clean startup.")
    except Exception as e:
        _log(f"System: Startup cleanup error: {e}")


# --- STALE JOB WATCHER ---
# Background thread that periodically detects jobs where the heartbeat has
# gone silent (>15 min) or the total run has exceeded 2 hours.

def _stale_job_watcher():
    import time as _time
    from datetime import datetime as _dt, timedelta as _td

    _HEARTBEAT_THRESHOLD = _td(minutes=15)
    _MAX_RUN_THRESHOLD = _td(hours=2)
    _CHECK_INTERVAL = 5 * 60  # seconds

    while True:
        _time.sleep(_CHECK_INTERVAL)
        try:
            with app.app_context():
                now = _dt.utcnow()
                stale = Run.query.filter_by(status='running').all()
                for r in stale:
                    # Check heartbeat first (shorter threshold)
                    if r.last_heartbeat and (now - r.last_heartbeat) > _HEARTBEAT_THRESHOLD:
                        _log(f"System: [StaleWatcher] Run #{r.id} heartbeat is {now - r.last_heartbeat} old — marking failed.")
                        r.status = 'failed'
                        r.end_time = now
                        db.session.add(r)
                    # Fallback: check start_time if no heartbeat recorded
                    elif not r.last_heartbeat and r.start_time and (now - r.start_time) > _MAX_RUN_THRESHOLD:
                        _log(f"System: [StaleWatcher] Run #{r.id} running {now - r.start_time} with no heartbeat — marking failed.")
                        r.status = 'failed'
                        r.end_time = now
                        db.session.add(r)
                db.session.commit()
        except Exception as _e:
            _log(f"System: [StaleWatcher] Error during stale-job check: {_e}")


# --- HUEY CONSUMER ---
# Start the Huey task consumer in a background thread whenever the app loads.
# Guard against the Werkzeug reloader spawning a second consumer in the child process,
# and against test runners or importers that should not start background workers.
import threading as _threading

def _start_huey_consumer():
    import logging as _logging
    # INFO level so task pick-up/completion appears in docker logs
    _logging.basicConfig(
        level=_logging.INFO,
        format='[%(asctime)s] HUEY %(levelname)s | %(message)s',
        datefmt='%H:%M:%S',
        stream=sys.stdout,
        force=True,
    )
    try:
        from huey.consumer import Consumer
        # NOTE: Huey 2.6.0 does NOT accept a `loglevel` kwarg — omit it.
        consumer = Consumer(huey, workers=1, worker_type='thread')
        _log("System: Huey task consumer started successfully.")
        consumer.run()  # blocks until app exits
    except Exception as e:
        msg = f"System: Huey consumer FAILED to start: {type(e).__name__}: {e}"
        _log(msg)
        # Also write to a persistent file for diagnosis when stdout is piped away
        try:
            _err_path = os.path.join(config.DATA_DIR, "consumer_error.log")
            with open(_err_path, 'a', encoding='utf-8') as _f:
                _f.write(f"[{datetime.utcnow().isoformat()}] {msg}\n")
        except Exception:
            pass

_is_reloader_child = os.environ.get('WERKZEUG_RUN_MAIN') == 'true'
_is_testing = os.environ.get('FLASK_TESTING') == '1'

if not _is_reloader_child and not _is_testing:
    _log("System: Launching Huey consumer thread...")
    _huey_thread = _threading.Thread(target=_start_huey_consumer, daemon=True, name="huey-consumer")
    _huey_thread.start()
    _log("System: Launching stale-job watcher thread (checks every 5 min)...")
    _watcher_thread = _threading.Thread(target=_stale_job_watcher, daemon=True, name="stale-job-watcher")
    _watcher_thread.start()
else:
    _log(f"System: Skipping Huey consumer (WERKZEUG_RUN_MAIN={os.environ.get('WERKZEUG_RUN_MAIN')}, FLASK_TESTING={os.environ.get('FLASK_TESTING')}).")


if __name__ == "__main__":
    app.run(host='0.0.0.0', port=5000, debug=False)