package database

import (
	"fmt"
	"slices"

	"gorm.io/gorm"
)

type mysqlIndexColumn struct {
	KeyName    string `gorm:"column:Key_name"`
	SeqInIndex int    `gorm:"column:Seq_in_index"`
	ColumnName string `gorm:"column:Column_name"`
}

func repairSmokeAINextSmokeIndexes(db *gorm.DB) error {
	if db == nil {
		return nil
	}

	const (
		tableName = "fa_smoke_ai_next_smoke"
		indexName = "uniq_smoke_ai_next_node"
	)

	var rows []mysqlIndexColumn
	if err := db.Raw(fmt.Sprintf("SHOW INDEX FROM `%s` WHERE Key_name = ?", tableName), indexName).Scan(&rows).Error; err != nil {
		return fmt.Errorf("inspect %s: %w", indexName, err)
	}

	expected := []string{"ai_advice_id", "node_type", "node_at"}
	actual := make([]string, 0, len(rows))
	for _, row := range rows {
		actual = append(actual, row.ColumnName)
	}

	if slices.Equal(actual, expected) {
		return nil
	}

	if len(rows) > 0 {
		if err := db.Exec(fmt.Sprintf("ALTER TABLE `%s` DROP INDEX `%s`", tableName, indexName)).Error; err != nil {
			return fmt.Errorf("drop %s: %w", indexName, err)
		}
	}

	if err := db.Exec(
		fmt.Sprintf(
			"ALTER TABLE `%s` ADD UNIQUE KEY `%s` (`ai_advice_id`,`node_type`,`node_at`)",
			tableName,
			indexName,
		),
	).Error; err != nil {
		return fmt.Errorf("create %s: %w", indexName, err)
	}

	return nil
}

func repairSmokeAIAdviceIndexes(db *gorm.DB) error {
	if db == nil {
		return nil
	}

	const (
		tableName = "fa_smoke_ai_advice"
		indexName = "uniq_smoke_ai_advice"
	)

	var rows []mysqlIndexColumn
	if err := db.Raw(fmt.Sprintf("SHOW INDEX FROM `%s` WHERE Key_name = ?", tableName), indexName).Scan(&rows).Error; err != nil {
		return fmt.Errorf("inspect %s: %w", indexName, err)
	}

	expected := []string{"uid", "type", "advice_date", "prompt_version"}
	actual := make([]string, 0, len(rows))
	for _, row := range rows {
		actual = append(actual, row.ColumnName)
	}

	if slices.Equal(actual, expected) {
		return nil
	}

	if len(rows) > 0 {
		if err := db.Exec(fmt.Sprintf("ALTER TABLE `%s` DROP INDEX `%s`", tableName, indexName)).Error; err != nil {
			return fmt.Errorf("drop %s: %w", indexName, err)
		}
	}

	if err := db.Exec(
		fmt.Sprintf(
			"ALTER TABLE `%s` ADD UNIQUE KEY `%s` (`uid`,`type`,`advice_date`,`prompt_version`)",
			tableName,
			indexName,
		),
	).Error; err != nil {
		return fmt.Errorf("create %s: %w", indexName, err)
	}

	return nil
}