"""
Script de migración para implementar sistema de roles
Crea tabla roles y migra usuarios existentes
"""
from sqlalchemy import create_engine, text
from app.core.config import settings

def migrate():
    engine = create_engine(settings.DATABASE_URL)
    
    with engine.connect() as conn:
        print("🔄 Iniciando migración de roles...")
        
        # 1. Crear tabla roles
        print("📋 Creando tabla roles...")
        conn.execute(text("""
            CREATE TABLE IF NOT EXISTS roles (
                id SERIAL PRIMARY KEY,
                name VARCHAR(50) UNIQUE NOT NULL,
                display_name VARCHAR(100) NOT NULL,
                description VARCHAR(255),
                can_manage_users BOOLEAN DEFAULT FALSE,
                can_manage_roles BOOLEAN DEFAULT FALSE,
                can_manage_checklists BOOLEAN DEFAULT FALSE,
                can_create_inspections BOOLEAN DEFAULT FALSE,
                can_view_all_inspections BOOLEAN DEFAULT FALSE,
                can_view_reports BOOLEAN DEFAULT FALSE,
                can_deactivate_inspections BOOLEAN DEFAULT FALSE,
                created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
            )
        """))
        conn.commit()
        
        # 2. Insertar roles predefinidos
        print("👥 Insertando roles predefinidos...")
        conn.execute(text("""
            INSERT INTO roles (name, display_name, description, 
                can_manage_users, can_manage_roles, can_manage_checklists,
                can_create_inspections, can_view_all_inspections, 
                can_view_reports, can_deactivate_inspections)
            VALUES 
                ('administrador', 'Administrador', 'Acceso completo al sistema',
                 TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE),
                ('asesor', 'Asesor', 'Acceso a reportes e informes',
                 FALSE, FALSE, FALSE, FALSE, TRUE, TRUE, FALSE),
                ('mecanico', 'Mecánico', 'Realizar inspecciones',
                 FALSE, FALSE, FALSE, TRUE, FALSE, FALSE, FALSE)
            ON CONFLICT (name) DO NOTHING
        """))
        conn.commit()
        
        # 3. Agregar columna role_id a users (temporal)
        print("🔧 Agregando columna role_id a usuarios...")
        conn.execute(text("""
            ALTER TABLE users ADD COLUMN IF NOT EXISTS role_id INTEGER
        """))
        conn.commit()
        
        # 4. Migrar datos: admin -> administrador (id=1)
        print("🔄 Migrando usuarios admin -> administrador...")
        conn.execute(text("""
            UPDATE users 
            SET role_id = (SELECT id FROM roles WHERE name = 'administrador')
            WHERE role = 'admin' AND role_id IS NULL
        """))
        conn.commit()
        
        # 5. Migrar datos: mechanic -> mecanico (id=3)
        print("🔄 Migrando usuarios mechanic -> mecanico...")
        conn.execute(text("""
            UPDATE users 
            SET role_id = (SELECT id FROM roles WHERE name = 'mecanico')
            WHERE role IN ('mechanic', 'mecanico') AND role_id IS NULL
        """))
        conn.commit()
        
        # 6. Verificar que todos tienen role_id
        result = conn.execute(text("SELECT COUNT(*) FROM users WHERE role_id IS NULL"))
        null_count = result.scalar()
        
        if null_count > 0:
            print(f"⚠️  Advertencia: {null_count} usuarios sin role_id asignado")
            print("   Asignando rol de mecánico por defecto...")
            conn.execute(text("""
                UPDATE users 
                SET role_id = (SELECT id FROM roles WHERE name = 'mecanico')
                WHERE role_id IS NULL
            """))
            conn.commit()
        
        # 7. Hacer role_id NOT NULL y crear foreign key
        print("🔒 Aplicando restricciones...")
        conn.execute(text("""
            ALTER TABLE users ALTER COLUMN role_id SET NOT NULL
        """))
        conn.execute(text("""
            ALTER TABLE users 
            ADD CONSTRAINT fk_users_role_id 
            FOREIGN KEY (role_id) REFERENCES roles(id)
        """))
        conn.commit()
        
        # 8. Eliminar columna role antigua
        print("🗑️  Eliminando columna role antigua...")
        conn.execute(text("""
            ALTER TABLE users DROP COLUMN IF EXISTS role
        """))
        conn.commit()
        
        # 9. Mostrar resumen
        print("\n✅ Migración completada!")
        print("\n📊 Resumen de roles:")
        
        result = conn.execute(text("""
            SELECT r.name, r.display_name, COUNT(u.id) as user_count
            FROM roles r
            LEFT JOIN users u ON u.role_id = r.id
            GROUP BY r.id, r.name, r.display_name
            ORDER BY r.id
        """))
        
        for row in result:
            print(f"   {row[1]}: {row[2]} usuario(s)")
        
        print("\n🎉 Sistema de roles implementado correctamente!")

if __name__ == "__main__":
    migrate()