"""add_full_text_search

Revision ID: 116b2f287eab
Revises: 0bc0f3ff0111
Create Date: 2025-08-07 11:27:38.473517

"""
from typing import Sequence, Union

from alembic import op
import sqlalchemy as sa


revision: str = '116b2f287eab'
down_revision: Union[str, None] = '0bc0f3ff0111'
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    conn = op.get_bind()
    if conn.dialect.name != 'postgresql':
        return
    
    op.execute("""
        ALTER TABLE transcript ADD COLUMN search_vector_en tsvector 
        GENERATED ALWAYS AS (
            setweight(to_tsvector('english', coalesce(title, '')), 'A') ||
            setweight(to_tsvector('english', coalesce(webvtt, '')), 'B')
        ) STORED
    """)
    
    op.create_index(
        'idx_transcript_search_vector_en',
        'transcript',
        ['search_vector_en'],
        postgresql_using='gin'
    )


def downgrade() -> None:
    conn = op.get_bind()
    if conn.dialect.name != 'postgresql':
        return
    
    op.drop_index('idx_transcript_search_vector_en', table_name='transcript')
    op.drop_column('transcript', 'search_vector_en')