package integration

import (
	"bytes"
	"database/sql"
	"encoding/json"
	"errors"
	"io"
	"net/http"

	"github.com/gin-gonic/gin"

	"cmautobuy/admin/config"
	"cmautobuy/admin/repository"
	"cmautobuy/admin/service"
)

const catalogMaxBody = 5 << 20

type Handler struct{ db *sql.DB }

// Register 只挂载第三方目录接口，不复用 Client 或网页登录中间件。
func Register(r *gin.Engine, db *sql.DB, cfg config.CatalogIntegrationConfig) {
	h := &Handler{db: db}
	g := r.Group("/api/v1/integrations/catalog", RequireCatalogToken(cfg))
	g.POST("/batches", h.CreateBatch)
	g.GET("/batches/:batch_id", h.GetBatch)
}

func (h *Handler) GetBatch(c *gin.Context) {
	run, err := repository.GetCatalogImportRun(h.db, integrationSource(c), c.Param("batch_id"))
	if errors.Is(err, repository.ErrCatalogImportRunNotFound) {
		integrationError(c, 404, "BATCH_NOT_FOUND", "批次不存在", false, nil)
		return
	}
	if err != nil {
		integrationError(c, 500, "INTERNAL_ERROR", "查询批次失败", true, nil)
		return
	}
	c.JSON(200, gin.H{"source": run.Source, "batch_id": run.BatchID, "update_policy": run.UpdatePolicy, "status": run.Status, "request_count": run.RequestCount, "conflict_count": run.ConflictCount, "observed_at": run.ObservedAt, "created_at": run.CreatedAt, "finished_at": run.FinishedAt, "counts": gin.H{"shopee_created": run.ShopeeCreated, "shopee_updated": run.ShopeeUpdated, "shopee_fields_filled": run.ShopeeFieldsFilled, "shopee_fields_same_source_updated": run.ShopeeFieldsSameSourceUpdated, "shopee_fields_manual_skipped": run.ShopeeFieldsManualSkipped, "shopee_fields_stale_skipped": run.ShopeeFieldsStaleSkipped, "sku_created": run.SKUCreated, "sku_updated": run.SKUUpdated, "sku_filled": run.SKUFilled, "sku_same_source_updated": run.SKUSameSourceUpdated, "sku_skipped": run.SKUSkipped, "sku_manual_skipped": run.SKUManualSkipped, "sku_stale_skipped": run.SKUStaleSkipped, "pdd_created": run.PddCreated, "pdd_updated": run.PddUpdated, "association_created": run.AssociationCreated, "association_unchanged": run.AssociationUnchanged}, "failure_count": run.FailureCount, "error_summary": run.ErrorSummary})
}

func (h *Handler) CreateBatch(c *gin.Context) {
	c.Request.Body = http.MaxBytesReader(c.Writer, c.Request.Body, catalogMaxBody)
	raw, err := io.ReadAll(c.Request.Body)
	if err != nil {
		if _, ok := err.(*http.MaxBytesError); ok {
			integrationError(c, 413, "PAYLOAD_TOO_LARGE", "请求体不能超过 5 MB", false, nil)
			return
		}
		integrationError(c, 400, "INVALID_BODY", "读取请求失败", false, nil)
		return
	}
	var req service.CatalogBatchRequest
	dec := json.NewDecoder(bytes.NewReader(raw))
	dec.DisallowUnknownFields()
	if err = dec.Decode(&req); err != nil {
		integrationError(c, 400, "INVALID_JSON", "请求体不是合法的商品目录 JSON", false, nil)
		return
	}
	if dec.Decode(&struct{}{}) != io.EOF {
		integrationError(c, 400, "INVALID_JSON", "请求体只能包含一个 JSON 对象", false, nil)
		return
	}
	resp, err := service.ImportCatalogBatch(h.db, integrationSource(c), req, raw)
	if err != nil {
		var catalogErr *service.CatalogError
		if errors.As(err, &catalogErr) {
			integrationError(c, catalogErr.Status, catalogErr.Code, catalogErr.Message, catalogErr.Retryable, catalogErr.Details)
			return
		}
		integrationError(c, 500, "INTERNAL_ERROR", "商品目录批次处理失败", true, nil)
		return
	}
	c.JSON(http.StatusOK, resp)
}