package routes

import (
	"bssapp-backend/auth"
	"bssapp-backend/db"
	"database/sql"
	"encoding/json"
	"errors"
	"net/http"
	"strings"
	"time"

	"github.com/gorilla/mux"
)

type ProductionUpdateLine struct {
	OrderLineID string `json:"OrderLineID"`
	ItemTypeCode int16  `json:"ItemTypeCode"`
	ItemCode     string `json:"ItemCode"`
	ColorCode    string `json:"ColorCode"`
	ItemDim1Code string `json:"ItemDim1Code"`
	ItemDim2Code string `json:"ItemDim2Code"`
	ItemDim3Code string `json:"ItemDim3Code"`
	LineDescription string `json:"LineDescription"`
}

type ProductionUpdateRequest struct {
	Lines         []ProductionUpdateLine `json:"lines"`
	InsertMissing bool                   `json:"insertMissing"`
}

type MissingVariant struct {
	ItemTypeCode int16  `json:"ItemTypeCode"`
	ItemCode     string `json:"ItemCode"`
	ColorCode    string `json:"ColorCode"`
	ItemDim1Code string `json:"ItemDim1Code"`
	ItemDim2Code string `json:"ItemDim2Code"`
	ItemDim3Code string `json:"ItemDim3Code"`
}

// ======================================================
// 📌 OrderProductionUpdateRoute — U ürün satırlarını güncelle
// ======================================================
func OrderProductionUpdateRoute(mssql *sql.DB) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {

		w.Header().Set("Content-Type", "application/json; charset=utf-8")

		id := mux.Vars(r)["id"]
		if id == "" {
			http.Error(w, "OrderHeaderID bulunamadı", http.StatusBadRequest)
			return
		}

		var req ProductionUpdateRequest
		if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
			http.Error(w, "Geçersiz JSON", http.StatusBadRequest)
			return
		}

		if len(req.Lines) == 0 {
			http.Error(w, "Satır bulunamadı", http.StatusBadRequest)
			return
		}

		claims, _ := auth.GetClaimsFromContext(r.Context())
		username := ""
		if claims != nil {
			username = claims.Username
		}
		if username == "" {
			username = "system"
		}

		tx, err := db.MssqlDB.Begin()
		if err != nil {
			http.Error(w, "İşlem başlatılamadı", http.StatusInternalServerError)
			return
		}
		defer tx.Rollback()

		// 1) Eksik varyantları kontrol et
		missingMap := make(map[string]MissingVariant)
		checkStmt, err := tx.Prepare(`
SELECT TOP 1 1
FROM dbo.prItemVariant
WHERE ItemTypeCode = @p1
  AND ItemCode = @p2
  AND ColorCode = @p3
  AND ISNULL(ItemDim1Code,'') = ISNULL(@p4,'')
  AND ISNULL(ItemDim2Code,'') = ISNULL(@p5,'')
  AND ISNULL(ItemDim3Code,'') = ISNULL(@p6,'')
`)
		if err != nil {
			http.Error(w, "Varyant kontrolü hazırlanamadı", http.StatusInternalServerError)
			return
		}
		defer checkStmt.Close()

		for _, ln := range req.Lines {
			if strings.TrimSpace(ln.ItemCode) == "" {
				http.Error(w, "Yeni model kodu boş", http.StatusBadRequest)
				return
			}
			row := checkStmt.QueryRow(
				ln.ItemTypeCode,
				ln.ItemCode,
				ln.ColorCode,
				ln.ItemDim1Code,
				ln.ItemDim2Code,
				ln.ItemDim3Code,
			)
			var ok int
			if err := row.Scan(&ok); err != nil {
				if errors.Is(err, sql.ErrNoRows) {
					key := strings.Join([]string{
						ln.ItemCode, ln.ColorCode, ln.ItemDim1Code, ln.ItemDim2Code, ln.ItemDim3Code,
					}, "|")
					missingMap[key] = MissingVariant{
						ItemTypeCode: ln.ItemTypeCode,
						ItemCode:     ln.ItemCode,
						ColorCode:    ln.ColorCode,
						ItemDim1Code: ln.ItemDim1Code,
						ItemDim2Code: ln.ItemDim2Code,
						ItemDim3Code: ln.ItemDim3Code,
					}
					continue
				}
				http.Error(w, "Varyant kontrolü hatası", http.StatusInternalServerError)
				return
			}
		}

		if len(missingMap) > 0 && !req.InsertMissing {
			missing := make([]MissingVariant, 0, len(missingMap))
			for _, v := range missingMap {
				missing = append(missing, v)
			}
			w.WriteHeader(http.StatusConflict)
			_ = json.NewEncoder(w).Encode(map[string]any{
				"missing": missing,
			})
			return
		}

		// 2) Eksikleri ekle (gerekirse)
		if len(missingMap) > 0 {
			// PLU üretimi (max + row_number)
			var basePlu int64
			if err := tx.QueryRow(`SELECT ISNULL(MAX(PLU),0) FROM dbo.prItemVariant WITH (UPDLOCK, HOLDLOCK)`).Scan(&basePlu); err != nil {
				http.Error(w, "PLU alınamadı", http.StatusInternalServerError)
				return
			}

			now := time.Now()
			i := int64(0)
			for _, v := range missingMap {
				i++
				if _, err := tx.Exec(`
INSERT INTO dbo.prItemVariant
(
	ItemTypeCode, ItemCode, ColorCode, ItemDim1Code, ItemDim2Code, ItemDim3Code,
	PLU, CreatedUserName, CreatedDate, LastUpdatedUserName, LastUpdatedDate
)
VALUES
(@p1,@p2,@p3,@p4,@p5,@p6,@p7,@p8,@p9,@p8,@p9)
`,
					v.ItemTypeCode,
					v.ItemCode,
					v.ColorCode,
					v.ItemDim1Code,
					v.ItemDim2Code,
					v.ItemDim3Code,
					basePlu+i,
					username,
					now,
				); err != nil {
					http.Error(w, "Varyant insert hatası", http.StatusInternalServerError)
					return
				}
			}
		}

		// 3) trOrderLine güncelle
		updStmt, err := tx.Prepare(`
UPDATE dbo.trOrderLine
SET
	ItemCode = @p1,
	ColorCode = @p2,
	ItemDim2Code = @p3,
	LineDescription = @p4,
	LastUpdatedUserName = @p5,
	LastUpdatedDate = @p6
WHERE OrderHeaderID = @p7
  AND OrderLineID = @p8
`)
		if err != nil {
			http.Error(w, "Update hazırlığı başarısız", http.StatusInternalServerError)
			return
		}
		defer updStmt.Close()

		now := time.Now()
		for _, ln := range req.Lines {
			if _, err := updStmt.Exec(
				ln.ItemCode,
				ln.ColorCode,
				ln.ItemDim2Code,
				ln.LineDescription,
				username,
				now,
				id,
				ln.OrderLineID,
			); err != nil {
				http.Error(w, "Satır güncelleme hatası", http.StatusInternalServerError)
				return
			}
		}

		if err := tx.Commit(); err != nil {
			http.Error(w, "Commit hatası", http.StatusInternalServerError)
			return
		}

		_ = json.NewEncoder(w).Encode(map[string]any{
			"status":  "ok",
			"updated": len(req.Lines),
		})
	})
}