package handlers

import (
	"context"

	"github.com/jackc/pgx/v5/pgxpool"
)

// EnsureResourceI18nColumns adds per-locale text columns and backfills from legacy fields.
func EnsureResourceI18nColumns(ctx context.Context, pool *pgxpool.Pool) error {
	_, err := pool.Exec(ctx, `
		ALTER TABLE resources ADD COLUMN IF NOT EXISTS title_zh_tw TEXT;
		ALTER TABLE resources ADD COLUMN IF NOT EXISTS title_zh_cn TEXT;
		ALTER TABLE resources ADD COLUMN IF NOT EXISTS title_en TEXT;
		ALTER TABLE resources ADD COLUMN IF NOT EXISTS description_zh_tw TEXT;
		ALTER TABLE resources ADD COLUMN IF NOT EXISTS description_zh_cn TEXT;
		ALTER TABLE resources ADD COLUMN IF NOT EXISTS description_en TEXT;
		ALTER TABLE resources ADD COLUMN IF NOT EXISTS body_text_zh_tw TEXT;
		ALTER TABLE resources ADD COLUMN IF NOT EXISTS body_text_zh_cn TEXT;
		ALTER TABLE resources ADD COLUMN IF NOT EXISTS body_text_en TEXT`)
	if err != nil {
		return err
	}
	_, err = pool.Exec(ctx, `
		UPDATE resources SET title_zh_tw = title WHERE COALESCE(title_zh_tw, '') = '' AND COALESCE(title, '') <> '';
		UPDATE resources SET description_zh_tw = description WHERE description_zh_tw IS NULL AND description IS NOT NULL;
		UPDATE resources SET body_text_zh_tw = body_text WHERE body_text_zh_tw IS NULL AND body_text IS NOT NULL;
		UPDATE resources SET title_zh_cn = title WHERE language = 'zh-CN' AND COALESCE(title_zh_cn, '') = '';
		UPDATE resources SET description_zh_cn = description WHERE language = 'zh-CN' AND description_zh_cn IS NULL;
		UPDATE resources SET body_text_zh_cn = body_text WHERE language = 'zh-CN' AND body_text_zh_cn IS NULL;
		UPDATE resources SET title_en = title WHERE language = 'en' AND COALESCE(title_en, '') = '';
		UPDATE resources SET description_en = description WHERE language = 'en' AND description_en IS NULL;
		UPDATE resources SET body_text_en = body_text WHERE language = 'en' AND body_text_en IS NULL;
		UPDATE resources SET title = COALESCE(NULLIF(title_zh_tw, ''), title);
		UPDATE resources SET description = description_zh_tw;
		UPDATE resources SET body_text = body_text_zh_tw`)
	return err
}