package routes

import (
	"bssapp-backend/auth"
	"bssapp-backend/models"
	"bssapp-backend/queries"
	"database/sql"
	"fmt"
	"net/http"
	"strings"
	"time"

	"github.com/xuri/excelize/v2"
)

func ExportCustomerBalanceExcelHandler(_ *sql.DB) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		claims, ok := auth.GetClaimsFromContext(r.Context())
		if !ok || claims == nil {
			http.Error(w, "unauthorized", http.StatusUnauthorized)
			return
		}

		selectedDate := strings.TrimSpace(r.URL.Query().Get("selected_date"))
		if selectedDate == "" {
			selectedDate = time.Now().Format("2006-01-02")
		}

		params := models.CustomerBalanceListParams{
			SelectedDate: selectedDate,
			CariSearch:   strings.TrimSpace(r.URL.Query().Get("cari_search")),
			CariIlkGrup:  strings.TrimSpace(r.URL.Query().Get("cari_ilk_grup")),
			Piyasa:       strings.TrimSpace(r.URL.Query().Get("piyasa")),
			Temsilci:     strings.TrimSpace(r.URL.Query().Get("temsilci")),
			RiskDurumu:   strings.TrimSpace(r.URL.Query().Get("risk_durumu")),
			IslemTipi:    strings.TrimSpace(r.URL.Query().Get("islem_tipi")),
			Ulke:         strings.TrimSpace(r.URL.Query().Get("ulke")),
			Il:           strings.TrimSpace(r.URL.Query().Get("il")),
			Ilce:         strings.TrimSpace(r.URL.Query().Get("ilce")),
		}

		excludeZero12 := parseBoolQuery(r.URL.Query().Get("exclude_zero_12"))
		excludeZero13 := parseBoolQuery(r.URL.Query().Get("exclude_zero_13"))

		rows, err := queries.GetCustomerBalanceList(r.Context(), params)
		if err != nil {
			http.Error(w, "db error: "+err.Error(), http.StatusInternalServerError)
			return
		}

		rows = filterCustomerBalanceRowsForPDF(rows, excludeZero12, excludeZero13)
		summaries, _ := buildCustomerBalancePDFData(rows)

		f := excelize.NewFile()
		sheet := "CariBakiye"
		f.SetSheetName("Sheet1", sheet)

		headers := []string{
			"Ana Cari Kodu",
			"Ana Cari Detay",
			"Piyasa",
			"Temsilci",
			"Risk Durumu",
			"1_2 Bakiye Pr.Br",
			"1_3 Bakiye Pr.Br",
			"1_2 USD Bakiye",
			"1_2 TRY Bakiye",
			"1_3 USD Bakiye",
			"1_3 TRY Bakiye",
			"Vade Gun",
			"Belge Tarihi Gun",
		}

		for i, h := range headers {
			cell, _ := excelize.CoordinatesToCellName(i+1, 1)
			f.SetCellValue(sheet, cell, h)
		}

		var totalUSD12, totalTRY12, totalUSD13, totalTRY13 float64
		var totalVadeBase, totalVadeSum, totalVadeBelgeSum float64
		totalPrBr12 := map[string]float64{}
		totalPrBr13 := map[string]float64{}

		for _, s := range summaries {
			totalUSD12 += s.USDBakiye12
			totalTRY12 += s.TLBakiye12
			totalUSD13 += s.USDBakiye13
			totalTRY13 += s.TLBakiye13
			w := absFloatExcel(s.USDBakiye12) + absFloatExcel(s.TLBakiye12) + absFloatExcel(s.USDBakiye13) + absFloatExcel(s.TLBakiye13)
			if w > 0 {
				totalVadeBase += w
				totalVadeSum += s.VadeGun * w
				totalVadeBelgeSum += s.VadeBelge * w
			}
			for k, v := range s.Bakiye12Map {
				totalPrBr12[k] += v
			}
			for k, v := range s.Bakiye13Map {
				totalPrBr13[k] += v
			}
		}

		totalVade := 0.0
		totalVadeBelge := 0.0
		if totalVadeBase > 0 {
			totalVade = totalVadeSum / totalVadeBase
			totalVadeBelge = totalVadeBelgeSum / totalVadeBase
		}

		f.SetSheetRow(sheet, "A2", &[]any{
			"TOPLAM",
			"",
			"",
			"",
			"",
			formatCurrencyMapPDF(totalPrBr12),
			formatCurrencyMapPDF(totalPrBr13),
			totalUSD12,
			totalTRY12,
			totalUSD13,
			totalTRY13,
			totalVade,
			totalVadeBelge,
		})

		rowNo := 3
		for _, s := range summaries {
			f.SetSheetRow(sheet, fmt.Sprintf("A%d", rowNo), &[]any{
				s.AnaCariKodu,
				s.AnaCariAdi,
				s.Piyasa,
				s.Temsilci,
				s.RiskDurumu,
				formatCurrencyMapPDF(s.Bakiye12Map),
				formatCurrencyMapPDF(s.Bakiye13Map),
				s.USDBakiye12,
				s.TLBakiye12,
				s.USDBakiye13,
				s.TLBakiye13,
				s.VadeGun,
				s.VadeBelge,
			})
			rowNo++
		}

		_ = f.SetColWidth(sheet, "A", "A", 16)
		_ = f.SetColWidth(sheet, "B", "B", 34)
		_ = f.SetColWidth(sheet, "C", "E", 18)
		_ = f.SetColWidth(sheet, "F", "G", 34)
		_ = f.SetColWidth(sheet, "H", "M", 18)

		buf, err := f.WriteToBuffer()
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		filename := fmt.Sprintf("cari_bakiye_listesi_%s.xlsx", time.Now().Format("20060102_150405"))
		w.Header().Set("Content-Type", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet")
		w.Header().Set("Content-Disposition", "attachment; filename=\""+filename+"\"")
		w.Header().Set("Content-Length", fmt.Sprint(len(buf.Bytes())))
		w.WriteHeader(http.StatusOK)
		_, _ = w.Write(buf.Bytes())
	}
}

func absFloatExcel(v float64) float64 {
	if v < 0 {
		return -v
	}
	return v
}