package services

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"net/url"
	"strings"
	"time"

	"service-warungpos-go/config"
)

const FonnteAPIURL = "https://api.fonnte.com/send"

func formatPhone(phone string) string {
	phone = strings.TrimSpace(phone)
	phone = strings.ReplaceAll(phone, " ", "")
	phone = strings.ReplaceAll(phone, "-", "")

	if strings.HasPrefix(phone, "0") {
		phone = "62" + phone[1:]
	} else if strings.HasPrefix(phone, "+") {
		phone = phone[1:]
	}
	return phone
}

func fmtRupiah(amount int) string {
	// Format ribuan dengan titik (contoh: 15000 menjadi Rp 15.000)
	str := fmt.Sprintf("%d", amount)
	var result []string
	length := len(str)
	for i := length; i > 0; i -= 3 {
		start := i - 3
		if start < 0 {
			start = 0
		}
		result = append([]string{str[start:i]}, result...)
	}
	return "Rp " + strings.Join(result, ".")
}

func divider(char string, length int) string {
	return strings.Repeat(char, length)
}

type WAItem struct {
	Name     string `json:"name"`
	Quantity int    `json:"quantity"`
	Price    int    `json:"price"`
}

func SendPaymentNotification(
	phone string,
	orderNumber string,
	totalAmount int,
	paymentMethod string,
	customerName string,
	items []WAItem,
	changeAmount int,
	storeName string,
	branchName string,
	branchAddress string,
	subTotal int,
	discountAmount int,
	servedBy string,
	pointsEarned int,
) bool {
	if config.GlobalConfig.FonnteToken == "" {
		log.Println("[WHATSAPP] Token Fonnte tidak dikonfigurasi, lewati kirim WhatsApp")
		return false
	}

	if phone == "" {
		log.Println("[WHATSAPP] Nomor telepon customer kosong, lewati kirim WhatsApp")
		return false
	}

	formattedPhone := formatPhone(phone)
	baseStore := storeName
	if baseStore == "" {
		baseStore = config.GlobalConfig.StoreName
	}
	if baseStore == "" {
		baseStore = "XOGM Go"
	}

	displayName := baseStore
	if branchName != "" {
		displayName = baseStore + " - " + branchName
	}

	methodLabel := "Nontunai"
	if paymentMethod == "cash" {
		methodLabel = "Tunai (Cash)"
	}

	// Buat isi pesan
	var lines []string
	lines = append(lines, "Berikut adalah e-receipt untuk transaksi Anda")
	lines = append(lines, orderNumber)
	lines = append(lines, "")
	
	now := time.Now()
	// Gunakan WIB atau UTC
	lines = append(lines, fmt.Sprintf("Pembayaran anda telah kami terima pada %s", now.Format("2006-01-02 15:04:05")))
	lines = append(lines, "")
	lines = append(lines, fmt.Sprintf("KWITANSI %s", strings.ToUpper(baseStore)))
	lines = append(lines, "")
	lines = append(lines, fmt.Sprintf("Outlet : %s", displayName))
	
	if branchAddress != "" {
		lines = append(lines, fmt.Sprintf("Alamat : %s", branchAddress))
	}
	lines = append(lines, divider("-", 30))

	lines = append(lines, fmt.Sprintf("No. Kwitansi : %s", orderNumber))
	if customerName != "" {
		lines = append(lines, fmt.Sprintf("Pelanggan    : %s", customerName))
	} else {
		lines = append(lines, "Pelanggan    : Umum")
	}
	
	if servedBy != "" {
		lines = append(lines, fmt.Sprintf("Kasir        : %s", servedBy))
	}
	
	lines = append(lines, fmt.Sprintf("Tanggal      : %s", now.Format("2006-01-02 15:04:05")))
	lines = append(lines, fmt.Sprintf("Pembayaran   : %s", methodLabel))
	lines = append(lines, divider("-", 30))

	if len(items) > 0 {
		lines = append(lines, "Layanan / Pesanan")
		for _, item := range items {
			subtotal := item.Price * item.Quantity
			lines = append(lines, fmt.Sprintf("- %s x%d — %s", item.Name, item.Quantity, fmtRupiah(subtotal)))
		}
		lines = append(lines, "")
	}

	lines = append(lines, "Ringkasan Pembayaran")
	if discountAmount > 0 {
		lines = append(lines, "- Voucher            : Ya")
	} else {
		lines = append(lines, "- Voucher            : Tidak")
	}
	
	if subTotal > 0 {
		lines = append(lines, fmt.Sprintf("- Sub Total          : %s", fmtRupiah(subTotal)))
	} else {
		// Fallback
		lines = append(lines, fmt.Sprintf("- Sub Total          : %s", fmtRupiah(totalAmount+discountAmount)))
	}

	lines = append(lines, fmt.Sprintf("- Potongan Voucher   : %s", fmtRupiah(discountAmount)))
	lines = append(lines, fmt.Sprintf("- Total Bayar        : %s", fmtRupiah(totalAmount)))
	
	if paymentMethod == "cash" {
		lines = append(lines, fmt.Sprintf("- Kembalian          : %s", fmtRupiah(changeAmount)))
	}
	
	if pointsEarned > 0 {
		lines = append(lines, fmt.Sprintf("- Poin Didapat       : %d Poin", pointsEarned))
	}

	lines = append(lines, divider("-", 30))
	lines = append(lines, "Terima kasih telah menggunakan jasa kami.")
	lines = append(lines, "")
	lines = append(lines, "Hormat kami,")
	lines = append(lines, "")
	lines = append(lines, displayName)
	lines = append(lines, "Jika Anda tidak merasa melakukan transaksi ini, segera hubungi kami.")

	message := strings.Join(lines, "\n")

	return postFonnte(formattedPhone, message)
}

func SendOtpWa(phone string, otpCode string) bool {
	if config.GlobalConfig.FonnteToken == "" {
		return false
	}

	formattedPhone := formatPhone(phone)
	storeName := config.GlobalConfig.StoreName
	if storeName == "" {
		storeName = "XOGM Go"
	}

	message := fmt.Sprintf("*%s*\n\nKode OTP Registrasi Anda adalah:\n*%s*\n\nKode ini berlaku selama 5 menit. Jangan berikan kode ini kepada siapa pun.", storeName, otpCode)

	return postFonnte(formattedPhone, message)
}

func SendResetPasswordOtpWa(phone string, otpCode string) bool {
	if config.GlobalConfig.FonnteToken == "" {
		return false
	}

	formattedPhone := formatPhone(phone)
	storeName := config.GlobalConfig.StoreName
	if storeName == "" {
		storeName = "XOGM Go"
	}

	message := fmt.Sprintf("*%s*\n\nKode OTP Reset Password Anda adalah:\n*%s*\n\nKode ini berlaku selama 10 menit. Jangan berikan kode ini kepada siapa pun.", storeName, otpCode)

	return postFonnte(formattedPhone, message)
}

func SendApprovalWa(phone string, storeName string, email string) bool {
	if config.GlobalConfig.FonnteToken == "" || phone == "" {
		return false
	}

	formattedPhone := formatPhone(phone)
	message := fmt.Sprintf("✅ *SELAMAT! AKUN ANDA TELAH DISETUJUI*\n\nPerusahaan/Toko *%s* sudah diaktifkan!\nAnda dapat mencoba login ke Dashboard Kasir sekarang menggunakan email:\n_%s_\n\n*PENTING*: Agar dapat mulai menerima transaksi, pastikan Anda melakukan pengisian saldo (Top Up) Wallet/Dompet terlebih dahulu melalui menu Top Up di aplikasi.\n\nSukses Selalu,\nTim Pengelola XOGM Go.", storeName, email)

	return postFonnte(formattedPhone, message)
}

func SendNewRegistrationAdminWa(adminPhone string, storeName string, ownerName string, email string, phone string) bool {
	if config.GlobalConfig.FonnteToken == "" || adminPhone == "" {
		return false
	}

	formattedPhone := formatPhone(adminPhone)
	message := fmt.Sprintf("🚨 *PENDAFTARAN BARU XOGM GO* 🚨\n\nAda pendaftar baru yang menunggu persetujuan (approval) Anda:\n\n*Nama Toko / PT*: %s\n*Nama Owner*: %s\n*Email*: %s\n*No HP*: %s\n\nSilakan cek Dashboard Super Admin untuk menyetujui akun ini.", storeName, ownerName, email, phone)

	return postFonnte(formattedPhone, message)
}

func postFonnte(target string, message string) bool {
	// Gunakan http client bawaan Go dengan timeout 15 detik
	client := &http.Client{Timeout: 15 * time.Second}

	// Payload dikirim sebagai form url encoded
	data := url.Values{}
	data.Set("target", target)
	data.Set("message", message)
	data.Set("countryCode", "62")

	req, err := http.NewRequest("POST", FonnteAPIURL, bytes.NewBufferString(data.Encode()))
	if err != nil {
		log.Printf("[WHATSAPP] Gagal membuat request Fonnte: %v", err)
		return false
	}

	req.Header.Set("Authorization", config.GlobalConfig.FonnteToken)
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")

	resp, err := client.Do(req)
	if err != nil {
		log.Printf("[WHATSAPP] Error kirim Fonnte: %v", err)
		return false
	}
	defer resp.Body.Close()

	bodyBytes, err := io.ReadAll(resp.Body)
	if err != nil {
		log.Printf("[WHATSAPP] Gagal membaca response Fonnte: %v", err)
		return false
	}

	var responseData map[string]interface{}
	if err := json.Unmarshal(bodyBytes, &responseData); err != nil {
		log.Printf("[WHATSAPP] Gagal parse JSON Fonnte: %v", err)
		return false
	}

	status, ok := responseData["status"].(bool)
	if ok && status {
		log.Printf("[WHATSAPP] Notification terkirim ke target %s", maskPhone(target))
		return true
	}

	reason := responseData["reason"]
	log.Printf("[WHATSAPP] Fonnte gagal mengirim: %v", reason)
	return false
}

func maskPhone(phone string) string {
	if len(phone) <= 6 {
		return phone
	}
	return phone[:4] + "****" + phone[len(phone)-2:]
}