"""initial migration

Revision ID: 001
Revises:
Create Date: 2024-02-11 00:00:00

"""
from alembic import op
import sqlalchemy as sa
from sqlalchemy.dialects import postgresql

# revision identifiers, used by Alembic.
revision = '001'
down_revision = None
branch_labels = None
depends_on = None


def upgrade():
    # Create users table
    op.create_table(
        'users',
        sa.Column('id', sa.Integer(), autoincrement=True, nullable=False),
        sa.Column('email', sa.String(length=255), nullable=False),
        sa.Column('hashed_password', sa.String(length=255), nullable=False),
        sa.Column('created_at', sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
        sa.Column('is_active', sa.Boolean(), server_default=sa.true(), nullable=False),
        sa.PrimaryKeyConstraint('id'),
        sa.UniqueConstraint('email', name='uq_users_email')
    )
    op.create_index('idx_users_email', 'users', ['email'], unique=True)
    
    # Create courses table
    op.create_table(
        'courses',
        sa.Column('id', sa.Integer(), autoincrement=True, nullable=False),
        sa.Column('title', sa.String(length=255), nullable=False),
        sa.Column('description', sa.Text(), nullable=False),
        sa.Column('level', sa.String(length=50), nullable=False),
        sa.Column('duration', sa.Integer(), server_default=sa.text('0'), nullable=False),
        sa.Column('author_id', sa.Integer(), nullable=False),
        sa.Column('is_published', sa.Boolean(), server_default=sa.false(), nullable=False),
        sa.Column('created_at', sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
        sa.Column('updated_at', sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
        sa.PrimaryKeyConstraint('id'),
        sa.ForeignKeyConstraint(['author_id'], ['users.id'], ondelete='CASCADE')
    )
    op.create_index('idx_courses_author_id', 'courses', ['author_id'])
    op.create_index('idx_courses_is_published', 'courses', ['is_published'])
    
    # Create course_modules table
    op.create_table(
        'course_modules',
        sa.Column('id', sa.Integer(), autoincrement=True, nullable=False),
        sa.Column('course_id', sa.Integer(), nullable=False),
        sa.Column('title', sa.String(length=255), nullable=False),
        sa.Column('description', sa.Text(), nullable=True),
        sa.Column('duration', sa.String(length=100), nullable=True),
        sa.Column('order_index', sa.Integer(), server_default=sa.text('0'), nullable=False),
        sa.Column('created_at', sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
        sa.Column('updated_at', sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
        sa.PrimaryKeyConstraint('id'),
        sa.ForeignKeyConstraint(['course_id'], ['courses.id'], ondelete='CASCADE')
    )
    op.create_index('idx_course_modules_course_id', 'course_modules', ['course_id'])
    
    # Create lessons table
    op.create_table(
        'lessons',
        sa.Column('id', sa.Integer(), autoincrement=True, nullable=False),
        sa.Column('module_id', sa.Integer(), nullable=False),
        sa.Column('title', sa.String(length=255), nullable=False),
        sa.Column('description', sa.Text(), nullable=True),
        sa.Column('order_index', sa.Integer(), server_default=sa.text('0'), nullable=False),
        sa.Column('created_at', sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
        sa.Column('updated_at', sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
        sa.PrimaryKeyConstraint('id'),
        sa.ForeignKeyConstraint(['module_id'], ['course_modules.id'], ondelete='CASCADE')
    )
    op.create_index('idx_lessons_module_id', 'lessons', ['module_id'])
    
    # Create lesson_steps table
    op.create_table(
        'lesson_steps',
        sa.Column('id', sa.Integer(), autoincrement=True, nullable=False),
        sa.Column('lesson_id', sa.Integer(), nullable=False),
        sa.Column('step_type', sa.String(length=50), nullable=False),
        sa.Column('title', sa.String(length=255), nullable=True),
        sa.Column('content', sa.Text(), nullable=True),
        sa.Column('order_index', sa.Integer(), server_default=sa.text('0'), nullable=False),
        sa.Column('created_at', sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
        sa.Column('updated_at', sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
        sa.PrimaryKeyConstraint('id'),
        sa.ForeignKeyConstraint(['lesson_id'], ['lessons.id'], ondelete='CASCADE')
    )
    op.create_index('idx_lesson_steps_lesson_id', 'lesson_steps', ['lesson_id'])
    
    # Create favorite_courses table
    op.create_table(
        'favorite_courses',
        sa.Column('user_id', sa.Integer(), nullable=False),
        sa.Column('course_id', sa.Integer(), nullable=False),
        sa.Column('added_at', sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
        sa.PrimaryKeyConstraint('user_id', 'course_id'),
        sa.ForeignKeyConstraint(['user_id'], ['users.id'], ondelete='CASCADE'),
        sa.ForeignKeyConstraint(['course_id'], ['courses.id'], ondelete='CASCADE')
    )
    
    # Create progress table
    op.create_table(
        'progress',
        sa.Column('user_id', sa.Integer(), nullable=False),
        sa.Column('course_id', sa.Integer(), nullable=False),
        sa.Column('completed_lessons', sa.Integer(), server_default=sa.text('0'), nullable=False),
        sa.Column('total_lessons', sa.Integer(), server_default=sa.text('0'), nullable=False),
        sa.Column('updated_at', sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
        sa.PrimaryKeyConstraint('user_id', 'course_id'),
        sa.ForeignKeyConstraint(['user_id'], ['users.id'], ondelete='CASCADE'),
        sa.ForeignKeyConstraint(['course_id'], ['courses.id'], ondelete='CASCADE')
    )
    
    # Insert seed data
    # Test user (password: Test1234)
    op.execute("""
        INSERT INTO users (email, hashed_password, is_active)
        VALUES ('test@example.com', '$2b$12$EixZaYVK1fsbw1ZfbX3OXePaWxn96p36WQoeG6Lruj3vjPGga31lW', true)
    """)
    
    # Sample courses
    op.execute("""
        INSERT INTO courses (title, description, level, duration, author_id, is_published)
        VALUES
        ('Python Fundamentals', 'Learn the basics of Python programming language including syntax, data types, and control structures.', 'beginner', 20,
            (SELECT id FROM users WHERE email = 'test@example.com'), true),
        ('Web Development with FastAPI', 'Build modern web applications using FastAPI framework with Python.', 'intermediate', 30,
            (SELECT id FROM users WHERE email = 'test@example.com'), true),
        ('Docker for Developers', 'Master containerization with Docker and Docker Compose for application deployment.', 'intermediate', 25,
            (SELECT id FROM users WHERE email = 'test@example.com'), true),
        ('Advanced Algorithms', 'Deep dive into complex algorithms and data structures for technical interviews.', 'advanced', 40,
            (SELECT id FROM users WHERE email = 'test@example.com'), true),
        ('JavaScript Essentials', 'Learn JavaScript from scratch including ES6+ features and DOM manipulation.', 'beginner', 25,
            (SELECT id FROM users WHERE email = 'test@example.com'), true),
        ('Database Design', 'Learn relational database design principles and SQL optimization techniques.', 'intermediate', 35,
            (SELECT id FROM users WHERE email = 'test@example.com'), true),
        ('Machine Learning Basics', 'Introduction to machine learning concepts and practical implementations.', 'advanced', 45,
            (SELECT id FROM users WHERE email = 'test@example.com'), true),
        ('DevOps Practices', 'Learn continuous integration, deployment, and infrastructure as code.', 'intermediate', 30,
            (SELECT id FROM users WHERE email = 'test@example.com'), true),
        ('React Frontend Development', 'Build modern user interfaces with React library and hooks.', 'intermediate', 35,
            (SELECT id FROM users WHERE email = 'test@example.com'), true),
        ('System Architecture', 'Design scalable and maintainable software system architectures.', 'advanced', 50,
            (SELECT id FROM users WHERE email = 'test@example.com'), true)
    """)


def downgrade():
    # Delete seed data first
    op.execute("DELETE FROM favorite_courses")
    op.execute("DELETE FROM progress")
    op.execute("DELETE FROM lesson_steps")
    op.execute("DELETE FROM lessons")
    op.execute("DELETE FROM course_modules")
    op.execute("DELETE FROM courses WHERE author_id = (SELECT id FROM users WHERE email = 'test@example.com')")
    op.execute("DELETE FROM users WHERE email = 'test@example.com'")
    
    # Drop tables
    op.drop_table('progress')
    op.drop_table('favorite_courses')
    op.drop_index('idx_lesson_steps_lesson_id', table_name='lesson_steps')
    op.drop_table('lesson_steps')
    op.drop_index('idx_lessons_module_id', table_name='lessons')
    op.drop_table('lessons')
    op.drop_index('idx_course_modules_course_id', table_name='course_modules')
    op.drop_table('course_modules')
    op.drop_index('idx_courses_is_published', table_name='courses')
    op.drop_index('idx_courses_author_id', table_name='courses')
    op.drop_table('courses')
    op.drop_index('idx_users_email', table_name='users')
    op.drop_table('users')