-- ============================================================================
-- Production migration: apikey.alias (unique) + markdown/patch authorship
-- ============================================================================
-- Idempotent. Safe to run multiple times. Target: MySQL 8 (no native
-- ADD COLUMN IF NOT EXISTS, so columns are guarded via information_schema
-- + a prepared statement). Mirrors the app's db.run_migrations(); running
-- both is harmless.
--
-- Apply against the application schema, e.g.:
--   docker exec -i mysql sh -c 'mysql -uroot -p"$MYSQL_ROOT_PASSWORD" hangmanlab' \
--       < 2026-05-16_apikey_alias_authorship.sql
-- ============================================================================

SET @schema := DATABASE();

-- ---- helper macro is not available in plain SQL; repeat the guarded block --

-- apikey.alias --------------------------------------------------------------
SET @c := (SELECT COUNT(*) FROM information_schema.columns
           WHERE table_schema=@schema AND table_name='apikey' AND column_name='alias');
SET @ddl := IF(@c=0,
    'ALTER TABLE apikey ADD COLUMN alias VARCHAR(255) NULL',
    'DO 0');
PREPARE st FROM @ddl; EXECUTE st; DEALLOCATE PREPARE st;
-- backfill: existing keys get alias = their (unique) key string
UPDATE apikey SET alias = `key` WHERE alias IS NULL;

-- apikey unique constraint on alias -----------------------------------------
SET @i := (SELECT COUNT(*) FROM information_schema.statistics
           WHERE table_schema=@schema AND table_name='apikey' AND index_name='uq_apikey_alias');
SET @ddl := IF(@i=0,
    'ALTER TABLE apikey ADD CONSTRAINT uq_apikey_alias UNIQUE (alias)',
    'DO 0');
PREPARE st FROM @ddl; EXECUTE st; DEALLOCATE PREPARE st;

-- markdown.updated_at -------------------------------------------------------
SET @c := (SELECT COUNT(*) FROM information_schema.columns
           WHERE table_schema=@schema AND table_name='markdown' AND column_name='updated_at');
SET @ddl := IF(@c=0,
    'ALTER TABLE markdown ADD COLUMN updated_at DATETIME NULL',
    'DO 0');
PREPARE st FROM @ddl; EXECUTE st; DEALLOCATE PREPARE st;
UPDATE markdown SET updated_at = created_at WHERE updated_at IS NULL;

-- markdown.author -----------------------------------------------------------
SET @c := (SELECT COUNT(*) FROM information_schema.columns
           WHERE table_schema=@schema AND table_name='markdown' AND column_name='author');
SET @ddl := IF(@c=0,
    'ALTER TABLE markdown ADD COLUMN author VARCHAR(255) NULL',
    'DO 0');
PREPARE st FROM @ddl; EXECUTE st; DEALLOCATE PREPARE st;
UPDATE markdown SET author = 'admin' WHERE author IS NULL;

-- markdown.last_modified_by -------------------------------------------------
SET @c := (SELECT COUNT(*) FROM information_schema.columns
           WHERE table_schema=@schema AND table_name='markdown' AND column_name='last_modified_by');
SET @ddl := IF(@c=0,
    'ALTER TABLE markdown ADD COLUMN last_modified_by VARCHAR(255) NULL',
    'DO 0');
PREPARE st FROM @ddl; EXECUTE st; DEALLOCATE PREPARE st;
UPDATE markdown SET last_modified_by = 'admin' WHERE last_modified_by IS NULL;

-- markdown_patch.author -----------------------------------------------------
SET @c := (SELECT COUNT(*) FROM information_schema.columns
           WHERE table_schema=@schema AND table_name='markdown_patch' AND column_name='author');
SET @ddl := IF(@c=0,
    'ALTER TABLE markdown_patch ADD COLUMN author VARCHAR(255) NULL',
    'DO 0');
PREPARE st FROM @ddl; EXECUTE st; DEALLOCATE PREPARE st;
UPDATE markdown_patch SET author = 'admin' WHERE author IS NULL;

-- markdown_patch.last_modified_by -------------------------------------------
SET @c := (SELECT COUNT(*) FROM information_schema.columns
           WHERE table_schema=@schema AND table_name='markdown_patch' AND column_name='last_modified_by');
SET @ddl := IF(@c=0,
    'ALTER TABLE markdown_patch ADD COLUMN last_modified_by VARCHAR(255) NULL',
    'DO 0');
PREPARE st FROM @ddl; EXECUTE st; DEALLOCATE PREPARE st;
UPDATE markdown_patch SET last_modified_by = 'admin' WHERE last_modified_by IS NULL;