# /home/Autopartes/pos/services/tenant_manager.py
"""Create and manage tenant databases."""

import os
import psycopg2
from psycopg2 import sql
from psycopg2.extensions import ISOLATION_LEVEL_AUTOCOMMIT
from config import MASTER_DB_URL, TENANT_DB_URL_TEMPLATE, TENANT_TEMPLATE_DB
from tenant_db import get_master_conn, get_tenant_conn_by_dbname

MIGRATIONS_DIR = os.path.join(os.path.dirname(os.path.dirname(__file__)), 'migrations')
SEED_DIR = os.path.join(os.path.dirname(os.path.dirname(__file__)), 'seed')


def ensure_master_tables():
    """Create tenants/subscriptions/schema_version tables in nexus_master if missing."""
    conn = get_master_conn()
    cur = conn.cursor()
    cur.execute("""
        CREATE TABLE IF NOT EXISTS tenants (
            id SERIAL PRIMARY KEY,
            name VARCHAR(200) NOT NULL,
            db_name VARCHAR(100) UNIQUE NOT NULL,
            rfc VARCHAR(13),
            plan VARCHAR(50) DEFAULT 'basic',
            is_active BOOLEAN DEFAULT TRUE,
            created_at TIMESTAMPTZ DEFAULT NOW()
        )
    """)
    cur.execute("""
        CREATE TABLE IF NOT EXISTS subscriptions (
            id SERIAL PRIMARY KEY,
            tenant_id INTEGER REFERENCES tenants(id),
            plan VARCHAR(50) NOT NULL,
            status VARCHAR(20) DEFAULT 'active',
            started_at TIMESTAMPTZ DEFAULT NOW(),
            expires_at TIMESTAMPTZ,
            stripe_id VARCHAR(100)
        )
    """)
    cur.execute("""
        CREATE TABLE IF NOT EXISTS tenant_schema_version (
            tenant_id INTEGER PRIMARY KEY REFERENCES tenants(id),
            version VARCHAR(20) NOT NULL DEFAULT 'v1.0',
            updated_at TIMESTAMPTZ DEFAULT NOW()
        )
    """)
    conn.commit()
    cur.close()
    conn.close()


def create_template_db():
    """Create tenant_template DB with full schema if it doesn't exist."""
    conn = psycopg2.connect(MASTER_DB_URL)
    conn.set_isolation_level(ISOLATION_LEVEL_AUTOCOMMIT)
    cur = conn.cursor()

    # Check if template already exists (idempotent — safe to call from multiple tasks)
    cur.execute("SELECT 1 FROM pg_database WHERE datname = %s", (TENANT_TEMPLATE_DB,))
    if cur.fetchone():
        cur.close()
        conn.close()
        return False  # Already exists

    # Use psycopg2.sql.Identifier for safe dynamic DB name
    cur.execute(
        sql.SQL('CREATE DATABASE {}').format(sql.Identifier(TENANT_TEMPLATE_DB))
    )
    cur.close()
    conn.close()

    # Apply schema to template
    tpl_conn = get_tenant_conn_by_dbname(TENANT_TEMPLATE_DB)
    tpl_cur = tpl_conn.cursor()

    schema_path = os.path.join(MIGRATIONS_DIR, 'v1.0_initial.sql')
    with open(schema_path) as f:
        tpl_cur.execute(f.read())

    seed_path = os.path.join(SEED_DIR, 'sat_accounts.sql')
    with open(seed_path) as f:
        tpl_cur.execute(f.read())

    tpl_conn.commit()
    tpl_cur.close()
    tpl_conn.close()
    return True  # Created


def provision_tenant(name, rfc=None, owner_name="Admin", owner_email=None, owner_pin="0000"):
    """Create a new tenant: register in master, create DB from template, create owner employee."""
    import bcrypt

    ensure_master_tables()
    create_template_db()

    # Generate db_name
    conn = get_master_conn()
    cur = conn.cursor()

    # Insert tenant
    cur.execute("""
        INSERT INTO tenants (name, db_name, rfc)
        VALUES (%s, %s, %s)
        RETURNING id, db_name
    """, (name, f"tenant_{name.lower().replace(' ', '_')[:30]}", rfc))
    tenant_id, db_name = cur.fetchone()

    # Track schema version
    cur.execute("""
        INSERT INTO tenant_schema_version (tenant_id, version)
        VALUES (%s, 'v1.0')
    """, (tenant_id,))
    conn.commit()
    cur.close()
    conn.close()

    # Create DB from template — use psycopg2.sql.Identifier for safe dynamic names
    master_conn = psycopg2.connect(MASTER_DB_URL)
    master_conn.set_isolation_level(ISOLATION_LEVEL_AUTOCOMMIT)
    master_cur = master_conn.cursor()
    master_cur.execute(
        sql.SQL('CREATE DATABASE {} TEMPLATE {}').format(
            sql.Identifier(db_name),
            sql.Identifier(TENANT_TEMPLATE_DB)
        )
    )
    master_cur.close()
    master_conn.close()

    # Create default branch and owner employee
    tenant_conn = get_tenant_conn_by_dbname(db_name)
    tenant_cur = tenant_conn.cursor()

    tenant_cur.execute("""
        INSERT INTO branches (name) VALUES ('Principal') RETURNING id
    """)
    branch_id = tenant_cur.fetchone()[0]

    pin_hash = bcrypt.hashpw(owner_pin.encode(), bcrypt.gensalt()).decode()
    pwd_hash = bcrypt.hashpw(owner_pin.encode(), bcrypt.gensalt()).decode()

    tenant_cur.execute("""
        INSERT INTO employees (name, email, pin, password_hash, role, branch_id, max_discount_pct, is_active)
        VALUES (%s, %s, %s, %s, 'owner', %s, 100, true)
        RETURNING id
    """, (owner_name, owner_email, pin_hash, pwd_hash, branch_id))
    owner_id = tenant_cur.fetchone()[0]

    # Grant all permissions to owner
    permissions = [
        'pos.sell', 'pos.discount', 'pos.cancel', 'pos.view_cost',
        'inventory.view', 'inventory.create', 'inventory.edit', 'inventory.adjust', 'inventory.transfer',
        'catalog.view', 'catalog.edit',
        'customers.view', 'customers.create', 'customers.edit', 'customers.edit_credit', 'customers.delete',
        'accounting.view', 'accounting.create', 'accounting.close',
        'invoicing.view', 'invoicing.create', 'invoicing.cancel',
        'reports.view', 'reports.financial',
        'config.view', 'config.edit', 'config.edit_prices'
    ]
    for perm in permissions:
        tenant_cur.execute(
            "INSERT INTO employee_permissions (employee_id, permission) VALUES (%s, %s)",
            (owner_id, perm)
        )

    tenant_conn.commit()
    tenant_cur.close()
    tenant_conn.close()

    return {'tenant_id': tenant_id, 'db_name': db_name, 'owner_id': owner_id}


def list_tenants():
    """List all tenants."""
    conn = get_master_conn()
    cur = conn.cursor()
    cur.execute("SELECT id, name, db_name, rfc, plan, is_active, created_at FROM tenants ORDER BY id")
    tenants = []
    for row in cur.fetchall():
        tenants.append({
            'id': row[0], 'name': row[1], 'db_name': row[2],
            'rfc': row[3], 'plan': row[4], 'is_active': row[5],
            'created_at': str(row[6])
        })
    cur.close()
    conn.close()
    return tenants