"""
models.py
=========
SQLite database layer for the Theme Song Booth.

This module defines the schema and all database operations. Flask's
application context (`g`) is used to manage one connection per request.

Schema overview (see SCHEMA constant):
- requests table stores customer data, generated prompts, file paths,
  approval state, email timestamps, payment reference, and player token.
- Indexes on status and player_token for fast queue/lookup.
"""

import sqlite3
import secrets
from datetime import datetime, timezone
from flask import current_app, g

# SQL executed by init_db() to create the requests table and indexes.
SCHEMA = """
CREATE TABLE IF NOT EXISTS requests (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    name TEXT NOT NULL,
    email TEXT NOT NULL,
    hobbies TEXT,
    notable_facts TEXT,
    style_genre TEXT,
    extra_requests TEXT,
    status TEXT DEFAULT 'pending',
    suno_title TEXT,
    suno_style TEXT,
    suno_lyrics TEXT,
    song_a_path TEXT,
    song_b_path TEXT,
    vocal_gender TEXT,
    customer_approved TEXT DEFAULT 'none',
    approval_notified_at TIMESTAMP,
    preview_sent_at TIMESTAMP,
    delivery_sent_at TIMESTAMP,
    square_payment_ref TEXT,
    admin_alert_email TEXT,
    player_token TEXT NOT NULL UNIQUE,
    revision_count INTEGER DEFAULT 0,
    revision_note TEXT
);

CREATE INDEX IF NOT EXISTS idx_requests_status ON requests(status);
CREATE INDEX IF NOT EXISTS idx_requests_token ON requests(player_token);
"""


def get_db():
    """Get or create a SQLite connection tied to the current Flask request context."""
    if 'db' not in g:
        g.db = sqlite3.connect(current_app.config['DATABASE'])
        g.db.row_factory = sqlite3.Row
    return g.db


def close_db(e=None):
    """Close the request-scoped SQLite connection. Registered as teardown handler."""
    db = g.pop('db', None)
    if db is not None:
        db.close()


def init_db():
    """Create the database file and tables. Safe to run multiple times."""
    db = sqlite3.connect(current_app.config['DATABASE'])
    db.executescript(SCHEMA)
    db.commit()
    db.close()


def new_token():
    """Generate a URL-safe random token used for private player links."""
    return secrets.token_urlsafe(32)


def now_utc():
    """Return current UTC time as ISO-8601 string for timestamp columns."""
    return datetime.now(timezone.utc).isoformat()


def create_request(name, email, hobbies, notable_facts, style_genre, extra_requests, vocal_gender=None):
    """
    Insert a new customer request.
    Returns the auto-generated request id.
    """
    db = get_db()
    cur = db.execute(
        """INSERT INTO requests
           (name, email, hobbies, notable_facts, style_genre, extra_requests, vocal_gender, player_token)
           VALUES (?, ?, ?, ?, ?, ?, ?, ?)""",
        (name, email, hobbies, notable_facts, style_genre, extra_requests, vocal_gender, new_token())
    )
    db.commit()
    return cur.lastrowid


def get_request_by_id(request_id):
    """Fetch one request by numeric id. Returns dict or None."""
    db = get_db()
    row = db.execute('SELECT * FROM requests WHERE id = ?', (request_id,)).fetchone()
    return dict(row) if row else None


def get_request_by_token(token):
    """Fetch one request by its private player token. Returns dict or None."""
    db = get_db()
    row = db.execute('SELECT * FROM requests WHERE player_token = ?', (token,)).fetchone()
    return dict(row) if row else None


def list_requests(status=None):
    """List all requests, optionally filtered by status, newest first."""
    db = get_db()
    if status:
        rows = db.execute('SELECT * FROM requests WHERE status = ? ORDER BY created_at DESC', (status,)).fetchall()
    else:
        rows = db.execute('SELECT * FROM requests ORDER BY created_at DESC').fetchall()
    return [dict(r) for r in rows]


def update_request(request_id, **fields):
    """
    Update arbitrary columns for a request.
    Example: update_request(1, status='prompt_ready', suno_style='...')
    """
    if not fields:
        return
    db = get_db()
    cols = ', '.join(f'{k} = ?' for k in fields)
    vals = list(fields.values()) + [request_id]
    db.execute(f'UPDATE requests SET {cols} WHERE id = ?', vals)
    db.commit()


def delete_request(request_id):
    """Delete a single request by id. Does NOT delete associated files."""
    db = get_db()
    db.execute('DELETE FROM requests WHERE id = ?', (request_id,))
    db.commit()


def reset_all_requests():
    """Delete every row in the requests table. Does NOT delete files."""
    db = get_db()
    db.execute('DELETE FROM requests')
    db.commit()