package pdf

import (
	"bytes"
	"fmt"
	"log"
	"os"
	"text/template"
	"time"

	"github.com/jung-kurt/gofpdf/v2"

	"github.com/rjNemo/rentease/assets"
	"github.com/rjNemo/rentease/internal/service/booking"
)

type HTMLPdfClient struct{}

const (
	invoiceMarginX      = 10.0
	invoiceContentWidth = 190.0
	invoiceHeaderHeight = 32.0
	invoiceTableRowH    = 9.0
	invoiceSummaryLineH = 9.0
	invoiceNotesPadding = 4.0
	invoiceColGap       = 6.0
	invoiceColWidth     = (invoiceContentWidth - invoiceColGap) / 2.0
)

type rgbColor struct {
	r int
	g int
	b int
}

var (
	invoiceTeal      = rgbColor{0, 123, 143}
	invoiceTealDark  = rgbColor{0, 98, 114}
	invoiceLightGray = rgbColor{248, 249, 250}
	invoiceMidGray   = rgbColor{222, 226, 230}
	invoiceTextGray  = rgbColor{73, 80, 87}
	invoiceTextMuted = rgbColor{108, 117, 125}
	invoiceNoteBg    = rgbColor{237, 247, 249}
	invoiceWhite     = rgbColor{255, 255, 255}
)

func NewPdfClient() (*HTMLPdfClient, error) {
	return &HTMLPdfClient{}, nil
}

func (pc *HTMLPdfClient) BuildInvoice(data booking.Invoice) (*booking.GeneratedFile, error) {
	pdf := gofpdf.New("P", "mm", "A4", "")
	pdf.SetMargins(invoiceMarginX, 10, invoiceMarginX)
	pdf.SetAutoPageBreak(true, 14)
	pdf.AddPage()

	tr := pdf.UnicodeTranslatorFromDescriptor("")
	drawInvoiceHeader(pdf, tr, data)
	drawInvoiceDetails(pdf, tr, data)
	drawInvoiceItemsTable(pdf, tr, data)
	drawInvoicePayments(pdf, tr, data)
	drawInvoiceSummary(pdf, tr, data)
	drawInvoiceNotes(pdf, tr, data)
	drawInvoiceFooter(pdf, tr, data)

	var buf bytes.Buffer
	if err := pdf.Output(&buf); err != nil {
		return nil, fmt.Errorf("error writing PDF file: %v", err)
	}

	return &booking.GeneratedFile{
		Name:        fmt.Sprintf("%s.pdf", data.ID),
		ContentType: "application/pdf",
		Data:        buf.Bytes(),
	}, nil
}

func (pc *HTMLPdfClient) BuildReport(report booking.ReportData, period string, month int, year int) (string, error) {
	tmpl, err := template.ParseFS(assets.Static, "assets/html/report.html")
	if err != nil {
		return "", fmt.Errorf("error parsing template: %v", err)
	}

	var buf bytes.Buffer
	if err := tmpl.Execute(&buf, report); err != nil {
		log.Printf("err: %+v\n", err)
		return "", fmt.Errorf("error executing template: %v", err)
	}

	outputPath := fmt.Sprintf("report-%s-%d-%d.html", period, month, year)
	if err := os.WriteFile(outputPath, buf.Bytes(), 0o644); err != nil {
		log.Printf("err: %+v\n", err)
		return "", fmt.Errorf("error writing HTML file: %v", err)
	}

	return outputPath, nil
}

func drawInvoiceHeader(pdf *gofpdf.Fpdf, tr func(string) string, data booking.Invoice) {
	topY := 10.0

	// Full-width teal banner
	pdf.SetFillColor(invoiceTeal.r, invoiceTeal.g, invoiceTeal.b)
	pdf.Rect(invoiceMarginX, topY, invoiceContentWidth, invoiceHeaderHeight, "F")

	// Subtle darker teal accent strip at very top
	pdf.SetFillColor(invoiceTealDark.r, invoiceTealDark.g, invoiceTealDark.b)
	pdf.Rect(invoiceMarginX, topY, invoiceContentWidth, 1.2, "F")

	// Logo in a white rounded rectangle
	if logo, err := assets.Static.ReadFile("assets/img/logo.png"); err == nil {
		info := pdf.RegisterImageOptionsReader(
			"invoice-logo",
			gofpdf.ImageOptions{ImageType: "PNG"},
			bytes.NewReader(logo),
		)
		if info != nil {
			logoX := invoiceMarginX + 5
			logoY := topY + 4
			logoSize := 24.0
			// white background circle behind logo
			pdf.SetFillColor(255, 255, 255)
			pdf.SetDrawColor(255, 255, 255)
			radius := logoSize/2 + 1.5
			pdf.Circle(logoX+logoSize/2, logoY+logoSize/2, radius, "F")
			pdf.ImageOptions("invoice-logo", logoX+1.5, logoY+1.5, logoSize-3, logoSize-3, false, gofpdf.ImageOptions{ImageType: "PNG"}, 0, "")
		}
	}

	// Host info on the right side of banner
	pdf.SetTextColor(255, 255, 255)
	rightBlockX := 100.0
	rightBlockW := invoiceMarginX + invoiceContentWidth - rightBlockX - 4

	pdf.SetXY(rightBlockX, topY+5)
	pdf.SetFont("Helvetica", "B", 13)
	pdf.CellFormat(rightBlockW, 5.5, tr(data.Host.Name), "", 1, "R", false, 0, "")

	pdf.SetFont("Helvetica", "", 8.5)
	hostLines := []string{
		data.Host.Address,
		fmt.Sprintf("%s %s", data.Host.ZipCode, data.Host.City),
		fmt.Sprintf("Tel : %s", data.Host.PhoneNumber),
		fmt.Sprintf("Mail : %s", data.Host.Email),
	}
	for _, line := range hostLines {
		pdf.SetX(rightBlockX)
		pdf.CellFormat(rightBlockW, 4.2, tr(line), "", 1, "R", false, 0, "")
	}

	// Invoice number badge below banner
	pdf.Ln(5)
	badgeY := pdf.GetY()
	pdf.SetFont("Helvetica", "", 9)
	pdf.SetTextColor(invoiceTextMuted.r, invoiceTextMuted.g, invoiceTextMuted.b)
	pdf.SetX(invoiceMarginX)
	pdf.CellFormat(80, 6, tr("FACTURE"), "", 0, "L", false, 0, "")

	pdf.SetFont("Helvetica", "B", 14)
	pdf.SetTextColor(invoiceTeal.r, invoiceTeal.g, invoiceTeal.b)
	pdf.CellFormat(invoiceContentWidth-80, 6, tr(data.ID), "", 1, "R", false, 0, "")

	pdf.SetDrawColor(invoiceTeal.r, invoiceTeal.g, invoiceTeal.b)
	pdf.SetLineWidth(0.4)
	pdf.Line(invoiceMarginX, badgeY+8, invoiceMarginX+invoiceContentWidth, badgeY+8)
	pdf.SetLineWidth(0.2)

	pdf.SetY(badgeY + 12)
}

func drawInvoiceDetails(pdf *gofpdf.Fpdf, tr func(string) string, data booking.Invoice) {
	startY := pdf.GetY()
	leftX := invoiceMarginX
	rightX := invoiceMarginX + invoiceColWidth + invoiceColGap
	cardPad := 5.0
	cardH := 36.0

	// Left card: Customer info - light gray background
	pdf.SetFillColor(invoiceLightGray.r, invoiceLightGray.g, invoiceLightGray.b)
	pdf.RoundedRect(leftX, startY, invoiceColWidth, cardH, 2, "1234", "F")

	// Section label
	pdf.SetXY(leftX+cardPad, startY+cardPad)
	pdf.SetFont("Helvetica", "", 7.5)
	pdf.SetTextColor(invoiceTextMuted.r, invoiceTextMuted.g, invoiceTextMuted.b)
	pdf.CellFormat(invoiceColWidth-cardPad*2, 4, tr("CLIENT"), "", 1, "L", false, 0, "")

	// Customer name
	pdf.SetX(leftX + cardPad)
	pdf.SetFont("Helvetica", "B", 12)
	pdf.SetTextColor(invoiceTextGray.r, invoiceTextGray.g, invoiceTextGray.b)
	pdf.CellFormat(invoiceColWidth-cardPad*2, 7, tr(data.Name), "", 1, "L", false, 0, "")

	// Customer details
	detailLineH := 5.5
	writeLeftDetail := func(label, value string) {
		pdf.SetX(leftX + cardPad)
		pdf.SetFont("Helvetica", "", 8.5)
		pdf.SetTextColor(invoiceTextMuted.r, invoiceTextMuted.g, invoiceTextMuted.b)
		pdf.CellFormat(28, detailLineH, tr(label), "", 0, "L", false, 0, "")
		pdf.SetFont("Helvetica", "", 9)
		pdf.SetTextColor(invoiceTextGray.r, invoiceTextGray.g, invoiceTextGray.b)
		pdf.CellFormat(invoiceColWidth-cardPad*2-28, detailLineH, tr(value), "", 1, "L", false, 0, "")
	}

	writeLeftDetail("Tel", emptyFallback(data.PhoneNumber))
	writeLeftDetail("Clients", fmt.Sprintf("%d", data.CustomersNumber))
	writeLeftDetail("Plateforme", data.Platform)

	// Right card: Booking info - light gray background
	pdf.SetFillColor(invoiceLightGray.r, invoiceLightGray.g, invoiceLightGray.b)
	pdf.RoundedRect(rightX, startY, invoiceColWidth, cardH, 2, "1234", "F")

	pdf.SetXY(rightX+cardPad, startY+cardPad)
	pdf.SetFont("Helvetica", "", 7.5)
	pdf.SetTextColor(invoiceTextMuted.r, invoiceTextMuted.g, invoiceTextMuted.b)
	pdf.CellFormat(invoiceColWidth-cardPad*2, 4, tr("SÉJOUR"), "", 1, "L", false, 0, "")

	writeRightDetail := func(label, value string, bold bool) {
		pdf.SetX(rightX + cardPad)
		pdf.SetFont("Helvetica", "", 8.5)
		pdf.SetTextColor(invoiceTextMuted.r, invoiceTextMuted.g, invoiceTextMuted.b)
		pdf.CellFormat(28, detailLineH, tr(label), "", 0, "L", false, 0, "")
		style := ""
		if bold {
			style = "B"
		}
		pdf.SetFont("Helvetica", style, 9.5)
		pdf.SetTextColor(invoiceTextGray.r, invoiceTextGray.g, invoiceTextGray.b)
		pdf.CellFormat(invoiceColWidth-cardPad*2-28, detailLineH, tr(value), "", 1, "L", false, 0, "")
	}

	// Date range as main heading
	pdf.SetX(rightX + cardPad)
	pdf.SetFont("Helvetica", "B", 12)
	pdf.SetTextColor(invoiceTextGray.r, invoiceTextGray.g, invoiceTextGray.b)
	pdf.CellFormat(invoiceColWidth-cardPad*2, 7, tr(fmt.Sprintf("%s  —  %s", data.From, data.To)), "", 1, "L", false, 0, "")

	writeRightDetail("Nuits", nightsCount(data.From, data.To), false)
	writeRightDetail("Montant", euroAmount(data.Total), true)

	pdf.SetY(startY + cardH + 8)
}

func drawInvoiceItemsTable(pdf *gofpdf.Fpdf, tr func(string) string, data booking.Invoice) {
	// Section title
	pdf.SetFont("Helvetica", "B", 11)
	pdf.SetTextColor(invoiceTeal.r, invoiceTeal.g, invoiceTeal.b)
	pdf.CellFormat(0, 7, tr("Prestations"), "", 1, "L", false, 0, "")
	pdf.Ln(1)

	widths := []float64{72, 30, 40, 48}
	headers := []string{"Objet", "Quantité", "Prix (€)", "Total (€)"}

	writeTableHeader(pdf, tr, widths, headers)

	pdf.SetFont("Helvetica", "", 10)
	for i, line := range data.Lines {
		fill := i%2 == 0
		if fill {
			pdf.SetFillColor(invoiceLightGray.r, invoiceLightGray.g, invoiceLightGray.b)
		}
		pdf.SetTextColor(invoiceTextGray.r, invoiceTextGray.g, invoiceTextGray.b)
		pdf.CellFormat(widths[0], invoiceTableRowH, "  "+tr(line.Name), "", 0, "", fill, 0, "")
		pdf.CellFormat(widths[1], invoiceTableRowH, fmt.Sprintf("%d", line.Quantity), "", 0, "C", fill, 0, "")
		pdf.CellFormat(widths[2], invoiceTableRowH, line.Price, "", 0, "R", fill, 0, "")
		pdf.SetTextColor(invoiceTextGray.r, invoiceTextGray.g, invoiceTextGray.b)
		pdf.SetFont("Helvetica", "B", 10)
		pdf.CellFormat(widths[3], invoiceTableRowH, line.Total+"  ", "", 1, "R", fill, 0, "")
		pdf.SetFont("Helvetica", "", 10)

		// Subtle separator line
		lineY := pdf.GetY()
		pdf.SetDrawColor(invoiceMidGray.r, invoiceMidGray.g, invoiceMidGray.b)
		pdf.Line(invoiceMarginX, lineY, invoiceMarginX+invoiceContentWidth, lineY)
	}

	pdf.Ln(8)
}

func drawInvoicePayments(pdf *gofpdf.Fpdf, tr func(string) string, data booking.Invoice) {
	pdf.SetFont("Helvetica", "B", 11)
	pdf.SetTextColor(invoiceTeal.r, invoiceTeal.g, invoiceTeal.b)
	pdf.CellFormat(0, 7, tr("Historique des Paiements"), "", 1, "L", false, 0, "")
	pdf.Ln(1)

	widths := []float64{54, 88, 48}
	headers := []string{"Date", "Mode de Paiement", "Montant (€)"}
	writeTableHeader(pdf, tr, widths, headers)

	pdf.SetFont("Helvetica", "", 10)
	if len(data.Payments) == 0 {
		pdf.SetFillColor(invoiceLightGray.r, invoiceLightGray.g, invoiceLightGray.b)
		pdf.SetTextColor(invoiceTextMuted.r, invoiceTextMuted.g, invoiceTextMuted.b)
		pdf.CellFormat(widths[0], invoiceTableRowH, "  "+tr("-"), "", 0, "", true, 0, "")
		pdf.CellFormat(widths[1], invoiceTableRowH, tr("Aucun paiement enregistré"), "", 0, "", true, 0, "")
		pdf.CellFormat(widths[2], invoiceTableRowH, tr("0.00")+"  ", "", 1, "R", true, 0, "")
	} else {
		for i, payment := range data.Payments {
			fill := i%2 == 0
			if fill {
				pdf.SetFillColor(invoiceLightGray.r, invoiceLightGray.g, invoiceLightGray.b)
			}
			pdf.SetTextColor(invoiceTextGray.r, invoiceTextGray.g, invoiceTextGray.b)
			pdf.CellFormat(widths[0], invoiceTableRowH, "  "+tr(payment.Date), "", 0, "", fill, 0, "")
			pdf.CellFormat(widths[1], invoiceTableRowH, tr(payment.Method), "", 0, "", fill, 0, "")
			pdf.SetFont("Helvetica", "B", 10)
			pdf.CellFormat(widths[2], invoiceTableRowH, payment.Amount+"  ", "", 1, "R", fill, 0, "")
			pdf.SetFont("Helvetica", "", 10)

			lineY := pdf.GetY()
			pdf.SetDrawColor(invoiceMidGray.r, invoiceMidGray.g, invoiceMidGray.b)
			pdf.Line(invoiceMarginX, lineY, invoiceMarginX+invoiceContentWidth, lineY)
		}
	}

	pdf.Ln(8)
}

func drawInvoiceSummary(pdf *gofpdf.Fpdf, tr func(string) string, data booking.Invoice) {
	// Right-aligned summary block
	summaryX := invoiceMarginX + invoiceContentWidth - 80
	summaryW := 80.0

	labels := []string{"Montant Total", "Montant Payé", "Solde Restant"}
	values := []string{euroAmount(data.Total), euroAmount(data.AmountPaid), euroAmount(data.BalanceDue)}

	for i := range labels {
		pdf.SetX(summaryX)
		pdf.SetFont("Helvetica", "", 9.5)
		pdf.SetTextColor(invoiceTextMuted.r, invoiceTextMuted.g, invoiceTextMuted.b)
		pdf.CellFormat(summaryW/2, invoiceSummaryLineH, tr(labels[i]), "", 0, "L", false, 0, "")
		pdf.SetFont("Helvetica", "B", 10)
		pdf.SetTextColor(invoiceTextGray.r, invoiceTextGray.g, invoiceTextGray.b)
		pdf.CellFormat(summaryW/2, invoiceSummaryLineH, tr(values[i]), "", 1, "R", false, 0, "")

		if i < len(labels)-1 {
			lineY := pdf.GetY()
			pdf.SetDrawColor(invoiceMidGray.r, invoiceMidGray.g, invoiceMidGray.b)
			pdf.Line(summaryX, lineY, summaryX+summaryW, lineY)
		}
	}

	// Highlight the balance due
	balanceY := pdf.GetY() - invoiceSummaryLineH
	pdf.SetFillColor(invoiceNoteBg.r, invoiceNoteBg.g, invoiceNoteBg.b)
	pdf.RoundedRect(summaryX-2, balanceY-0.5, summaryW+4, invoiceSummaryLineH+1, 1.5, "1234", "F")
	pdf.SetXY(summaryX, balanceY)
	pdf.SetFont("Helvetica", "B", 9.5)
	pdf.SetTextColor(invoiceTeal.r, invoiceTeal.g, invoiceTeal.b)
	pdf.CellFormat(summaryW/2, invoiceSummaryLineH, tr("Solde Restant"), "", 0, "L", false, 0, "")
	pdf.SetFont("Helvetica", "B", 11)
	pdf.CellFormat(summaryW/2, invoiceSummaryLineH, tr(euroAmount(data.BalanceDue)), "", 1, "R", false, 0, "")

	pdf.Ln(8)
}

func drawInvoiceNotes(pdf *gofpdf.Fpdf, tr func(string) string, _ booking.Invoice) {
	notes := "TVA non applicable, art. 293 B du CGI\nDispensé d'immatriculation au registre du commerce et des sociétés (RCS) et au répertoire des métiers.\nConditions de paiement : paiement à réception de facture. Aucun escompte consenti pour règlement anticipé ou désistement. Tout incident de paiement est passible d'intérêts de retard. Le montant des pénalités résulte de l'application aux sommes restant dues d'un taux d'intérêt légal en vigueur au moment de l'incident.\nIl sera demandé 15€ par jour par personne supplémentaire."

	pdf.SetFont("Helvetica", "", 7)
	lines := pdf.SplitLines([]byte(tr(notes)), invoiceContentWidth-(invoiceNotesPadding*2)-8)
	noteBoxHeight := float64(len(lines))*3.0 + invoiceNotesPadding*2 + 6

	if pdf.GetY()+noteBoxHeight+30 > 282 {
		pdf.AddPage()
	}

	y := pdf.GetY()
	pdf.SetFillColor(invoiceLightGray.r, invoiceLightGray.g, invoiceLightGray.b)
	pdf.RoundedRect(invoiceMarginX, y, invoiceContentWidth, noteBoxHeight, 2, "1234", "F")

	// Notes title
	pdf.SetXY(invoiceMarginX+invoiceNotesPadding, y+invoiceNotesPadding)
	pdf.SetFont("Helvetica", "B", 7.5)
	pdf.SetTextColor(invoiceTextMuted.r, invoiceTextMuted.g, invoiceTextMuted.b)
	pdf.CellFormat(invoiceContentWidth-(invoiceNotesPadding*2), 4, tr("MENTIONS LÉGALES"), "", 1, "L", false, 0, "")

	pdf.SetX(invoiceMarginX + invoiceNotesPadding)
	pdf.SetFont("Helvetica", "", 7)
	pdf.SetTextColor(invoiceTextMuted.r, invoiceTextMuted.g, invoiceTextMuted.b)
	pdf.MultiCell(invoiceContentWidth-(invoiceNotesPadding*2), 3.0, tr(notes), "", "L", false)

	pdf.SetY(y + noteBoxHeight + 6)
}

func drawInvoiceFooter(pdf *gofpdf.Fpdf, tr func(string) string, data booking.Invoice) {
	// Total banner at the bottom
	footerH := 14.0
	y := pdf.GetY()

	pdf.SetFillColor(invoiceTeal.r, invoiceTeal.g, invoiceTeal.b)
	pdf.RoundedRect(invoiceMarginX, y, invoiceContentWidth, footerH, 2, "1234", "F")

	pdf.SetXY(invoiceMarginX+6, y+2)
	pdf.SetFont("Helvetica", "", 9)
	pdf.SetTextColor(255, 255, 255)
	pdf.CellFormat(60, 10, tr("TOTAL À PAYER"), "", 0, "L", false, 0, "")

	pdf.SetFont("Helvetica", "B", 16)
	pdf.CellFormat(invoiceContentWidth-72, 10, tr(euroAmount(data.Total)), "", 0, "R", false, 0, "")
}

func writeTableHeader(pdf *gofpdf.Fpdf, tr func(string) string, widths []float64, headers []string) {
	pdf.SetFillColor(invoiceTeal.r, invoiceTeal.g, invoiceTeal.b)
	pdf.SetTextColor(255, 255, 255)
	pdf.SetFont("Helvetica", "B", 9)
	alignments := []string{"L", "C", "R", "R"}
	if len(widths) == 3 {
		alignments = []string{"L", "L", "R"}
	}
	for i, header := range headers {
		end := 0
		if i == len(headers)-1 {
			end = 1
		}
		pad := ""
		if i == 0 {
			pad = "  "
		}
		pdf.CellFormat(widths[i], 8, pad+tr(header), "", end, alignments[i], true, 0, "")
	}
}

func nightsCount(from, to string) string {
	f, err1 := time.Parse("02/01/2006", from)
	t, err2 := time.Parse("02/01/2006", to)
	if err1 != nil || err2 != nil {
		return "-"
	}
	days := int(t.Sub(f).Hours() / 24)
	if days < 0 {
		days = 0
	}
	return fmt.Sprintf("%d", days)
}

func euroAmount(value string) string {
	return fmt.Sprintf("%s €", value)
}

func emptyFallback(value string) string {
	if value == "" {
		return "-"
	}
	return value
}