-- Database Migration SQL Script
-- Run this with a database user that has CREATE privilege
-- Command: psql -U postgres -d church_songlyric -f migration.sql

-- OR connect as the database owner:
-- psql -U songlyric_user -d church_songlyric -f migration.sql

BEGIN;

-- Add indexes for performance (10-100x faster queries)
CREATE INDEX IF NOT EXISTS idx_profile_name ON profiles(name);
CREATE INDEX IF NOT EXISTS idx_song_title ON songs(title);
CREATE INDEX IF NOT EXISTS idx_song_artist ON songs(artist);
CREATE INDEX IF NOT EXISTS idx_song_band ON songs(band);
CREATE INDEX IF NOT EXISTS idx_plan_date ON plans(date);
CREATE INDEX IF NOT EXISTS idx_plan_profile ON plans(profile_id);
CREATE INDEX IF NOT EXISTS idx_plan_songs_plan ON plan_songs(plan_id);
CREATE INDEX IF NOT EXISTS idx_plan_songs_order ON plan_songs(plan_id, order_index);
CREATE INDEX IF NOT EXISTS idx_profile_songs_profile ON profile_songs(profile_id);
CREATE INDEX IF NOT EXISTS idx_profile_song_keys ON profile_song_keys(profile_id, song_id);

-- Add unique constraints to prevent duplicates
-- Note: These will fail if duplicate data exists - clean data first

-- Check for duplicates first:
-- SELECT plan_id, song_id, COUNT(*) FROM plan_songs GROUP BY plan_id, song_id HAVING COUNT(*) > 1;
-- SELECT profile_id, song_id, COUNT(*) FROM profile_songs GROUP BY profile_id, song_id HAVING COUNT(*) > 1;
-- SELECT profile_id, song_id, COUNT(*) FROM profile_song_keys GROUP BY profile_id, song_id HAVING COUNT(*) > 1;

DO $$ 
BEGIN
    IF NOT EXISTS (
        SELECT 1 FROM pg_constraint WHERE conname = 'uq_plan_song'
    ) THEN
        ALTER TABLE plan_songs ADD CONSTRAINT uq_plan_song UNIQUE (plan_id, song_id);
    END IF;
END $$;

DO $$ 
BEGIN
    IF NOT EXISTS (
        SELECT 1 FROM pg_constraint WHERE conname = 'uq_profile_song'
    ) THEN
        ALTER TABLE profile_songs ADD CONSTRAINT uq_profile_song UNIQUE (profile_id, song_id);
    END IF;
END $$;

DO $$ 
BEGIN
    IF NOT EXISTS (
        SELECT 1 FROM pg_constraint WHERE conname = 'uq_profile_song_key'
    ) THEN
        ALTER TABLE profile_song_keys ADD CONSTRAINT uq_profile_song_key UNIQUE (profile_id, song_id);
    END IF;
END $$;

COMMIT;

-- Verify indexes were created
SELECT schemaname, tablename, indexname 
FROM pg_indexes 
WHERE tablename IN ('profiles', 'songs', 'plans', 'plan_songs', 'profile_songs', 'profile_song_keys')
ORDER BY tablename, indexname;

-- Verify constraints were created
SELECT conname, contype, conrelid::regclass AS table_name
FROM pg_constraint
WHERE conname IN ('uq_plan_song', 'uq_profile_song', 'uq_profile_song_key');