package repository

import (
	"database/sql"
	"errors"
	"fmt"
	"strings"

	"github.com/go-sql-driver/mysql"

	"cmautobuy/admin/model"
)

var (
	// ErrCatalogImportRunExists 表示同一来源的批次号已经登记，由 service 判断是否重放。
	ErrCatalogImportRunExists   = errors.New("商品目录批次已经存在")
	ErrCatalogImportRunNotFound = errors.New("商品目录批次不存在")
)

// InsertCatalogImportRun 先登记 processing 批次；表的复合主键是并发幂等的最终防线。
func InsertCatalogImportRun(q Execer, run model.CatalogImportRun) error {
	_, err := q.Exec(`INSERT INTO catalog_import_runs (
		source,batch_id,request_hash,status,request_count,conflict_count,observed_at,
		last_request_at,created_at
	) VALUES (?,?,?,?,1,0,NULLIF(?,''),?,?)`, run.Source, run.BatchID, run.RequestHash,
		run.Status, run.ObservedAt, run.LastRequestAt, run.CreatedAt)
	if err == nil {
		return nil
	}
	var mysqlErr *mysql.MySQLError
	if errors.As(err, &mysqlErr) && mysqlErr.Number == 1062 {
		return ErrCatalogImportRunExists
	}
	if strings.Contains(strings.ToLower(err.Error()), "unique constraint failed") {
		return ErrCatalogImportRunExists
	}
	return fmt.Errorf("登记商品目录批次失败: %w", err)
}

// GetCatalogImportRun 查询一个批次的摘要，不读取原始请求体。
func GetCatalogImportRun(q Execer, source, batchID string) (model.CatalogImportRun, error) {
	var run model.CatalogImportRun
	var observedAt, lastConflictAt, errorSummary, responseBody, finishedAt sql.NullString
	err := q.QueryRow(`SELECT source,batch_id,request_hash,status,request_count,conflict_count,
		observed_at,last_request_at,last_conflict_at,shopee_created,shopee_updated,sku_created,
		sku_updated,pdd_created,pdd_updated,association_created,association_unchanged,failure_count,
		error_summary,response_body,created_at,finished_at
		FROM catalog_import_runs WHERE source=? AND batch_id=?`, source, batchID).Scan(
		&run.Source, &run.BatchID, &run.RequestHash, &run.Status, &run.RequestCount, &run.ConflictCount,
		&observedAt, &run.LastRequestAt, &lastConflictAt, &run.ShopeeCreated, &run.ShopeeUpdated,
		&run.SKUCreated, &run.SKUUpdated, &run.PddCreated, &run.PddUpdated, &run.AssociationCreated,
		&run.AssociationUnchanged, &run.FailureCount, &errorSummary, &responseBody, &run.CreatedAt, &finishedAt)
	if errors.Is(err, sql.ErrNoRows) {
		return model.CatalogImportRun{}, ErrCatalogImportRunNotFound
	}
	if err != nil {
		return model.CatalogImportRun{}, fmt.Errorf("查询商品目录批次失败: %w", err)
	}
	run.ObservedAt = observedAt.String
	run.LastConflictAt = lastConflictAt.String
	run.ErrorSummary = errorSummary.String
	run.ResponseBody = responseBody.String
	run.FinishedAt = finishedAt.String
	return run, nil
}

// RecordCatalogImportReplay 记录相同请求的重复提交，业务数据不会再次写入。
func RecordCatalogImportReplay(q Execer, source, batchID, requestedAt string) error {
	result, err := q.Exec(`UPDATE catalog_import_runs SET request_count=request_count+1,last_request_at=?
		WHERE source=? AND batch_id=?`, requestedAt, source, batchID)
	return catalogRunUpdateResult(result, err, "记录商品目录批次重放")
}

// RecordCatalogImportConflict 记录同一批次号携带不同内容的冲突。
func RecordCatalogImportConflict(q Execer, source, batchID, requestedAt string) error {
	result, err := q.Exec(`UPDATE catalog_import_runs SET request_count=request_count+1,
		conflict_count=conflict_count+1,last_request_at=?,last_conflict_at=?
		WHERE source=? AND batch_id=?`, requestedAt, requestedAt, source, batchID)
	return catalogRunUpdateResult(result, err, "记录商品目录批次冲突")
}

func catalogRunUpdateResult(result sql.Result, err error, action string) error {
	if err != nil {
		return fmt.Errorf("%s失败: %w", action, err)
	}
	affected, err := result.RowsAffected()
	if err != nil {
		return fmt.Errorf("读取%s结果失败: %w", action, err)
	}
	if affected == 0 {
		return ErrCatalogImportRunNotFound
	}
	return nil
}