//go:build windows

package main

import (
	"encoding/csv"
	"encoding/json"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"syscall"
	"time"
	"unsafe"
)

var (
	kernel32                = syscall.NewLazyDLL("kernel32.dll")
	procMultiByteToWideChar = kernel32.NewProc("MultiByteToWideChar")
)

// ansiToUtf8 converts ANSI (CP_ACP) bytes to UTF-8 string
func ansiToUtf8(b []byte) (string, error) {
	if len(b) == 0 {
		return "", nil
	}

	// CP_ACP = 0
	// 1. Get required length
	ret, _, _ := procMultiByteToWideChar.Call(
		0, // CP_ACP
		0,
		uintptr(unsafe.Pointer(&b[0])),
		uintptr(len(b)),
		0,
		0,
	)
	if ret == 0 {
		return "", fmt.Errorf("MultiByteToWideChar failed")
	}

	// 2. Allocate buffer
	utf16buf := make([]uint16, ret)

	// 3. Convert
	ret, _, _ = procMultiByteToWideChar.Call(
		0,
		0,
		uintptr(unsafe.Pointer(&b[0])),
		uintptr(len(b)),
		uintptr(unsafe.Pointer(&utf16buf[0])),
		ret,
	)
	if ret == 0 {
		return "", fmt.Errorf("MultiByteToWideChar failed")
	}

	return syscall.UTF16ToString(utf16buf), nil
}

// decodeCmdOutput handles WMIC encoding quirks (UTF-16LE BOM or ANSI)
func decodeCmdOutput(output []byte) (string, error) {
	if len(output) >= 2 && output[0] == 0xFF && output[1] == 0xFE {
		// UTF-16LE BOM detected
		// Skip BOM
		raw16 := output[2:]
		// Make sure even number of bytes
		if len(raw16)%2 != 0 {
			raw16 = append(raw16, 0)
		}
		u16s := make([]uint16, len(raw16)/2)
		for i := 0; i < len(u16s); i++ {
			u16s[i] = uint16(raw16[i*2]) | uint16(raw16[i*2+1])<<8
		}
		return syscall.UTF16ToString(u16s), nil
	}

	// Assume ANSI (e.g. GBK on Chinese Windows)
	return ansiToUtf8(output)
}

func (b *Bridge) getPrintersPlatform() ([]PrinterInfo, error) {
	// Use WMIC to get printer names and default flags in CSV format
	cmd := exec.Command("wmic", "printer", "get", "name,default", "/format:csv")
	cmd.SysProcAttr = &syscall.SysProcAttr{HideWindow: true}

	output, err := cmd.Output()
	if err != nil {
		return getPrintersViaPowerShell()
	}

	decodedStr, err := decodeCmdOutput(output)
	if err != nil {
		// Fallback
		decodedStr = string(output)
	}

	reader := csv.NewReader(strings.NewReader(decodedStr))
	reader.FieldsPerRecord = -1
	reader.LazyQuotes = true
	records, err := reader.ReadAll()
	if err != nil {
		return getPrintersViaPowerShell()
	}

	var printers []PrinterInfo
	for _, record := range records {
		if len(record) < 3 {
			continue
		}
		if strings.EqualFold(record[1], "Default") && strings.EqualFold(record[2], "Name") {
			continue
		}
		name := strings.TrimSpace(record[len(record)-1])
		if name == "" {
			continue
		}
		if strings.EqualFold(name, "Name") {
			continue
		}
		isDefault := strings.EqualFold(strings.TrimSpace(record[1]), "TRUE")
		printers = append(printers, PrinterInfo{Name: name, IsDefault: isDefault})
	}
	if len(printers) == 0 {
		return getPrintersViaPowerShell()
	}
	return printers, nil
}

func getPrintersViaPowerShell() ([]PrinterInfo, error) {
	ps := `Get-Printer | Select-Object Name,Default | ConvertTo-Json -Depth 3`
	cmd := exec.Command("powershell", "-NoProfile", "-NonInteractive", "-Command", ps)
	cmd.SysProcAttr = &syscall.SysProcAttr{HideWindow: true}
	output, err := cmd.Output()
	if err != nil {
		return nil, err
	}

	decoded, err := decodeCmdOutput(output)
	if err != nil {
		decoded = string(output)
	}

	var list []struct {
		Name    string `json:"Name"`
		Default bool   `json:"Default"`
	}
	if err := json.Unmarshal([]byte(decoded), &list); err == nil {
		printers := make([]PrinterInfo, 0, len(list))
		for _, item := range list {
			name := strings.TrimSpace(item.Name)
			if name == "" {
				continue
			}
			printers = append(printers, PrinterInfo{Name: name, IsDefault: item.Default})
		}
		return printers, nil
	}

	var single struct {
		Name    string `json:"Name"`
		Default bool   `json:"Default"`
	}
	if err := json.Unmarshal([]byte(decoded), &single); err != nil {
		return nil, err
	}
	name := strings.TrimSpace(single.Name)
	if name == "" {
		return nil, fmt.Errorf("no printers found")
	}
	return []PrinterInfo{{Name: name, IsDefault: single.Default}}, nil
}

func (b *Bridge) getPrinterCapabilitiesPlatform(printerName string) (map[string]interface{}, error) {
	printerName = strings.TrimSpace(printerName)
	if printerName == "" {
		return nil, fmt.Errorf("printer name is empty")
	}

	escaped := strings.ReplaceAll(printerName, "'", "''")
	ps := fmt.Sprintf(`$p = Get-CimInstance Win32_Printer -Filter "Name='%s'"; `+
		`$c = Get-CimInstance Win32_PrinterConfiguration -Filter "Name='%s'"; `+
		`if ($null -eq $p) { throw "Printer not found" }; `+
		`[pscustomobject]@{ `+
		`name = $p.Name; `+
		`defaultPaperSize = $p.DefaultPaperSize; `+
		`printerPaperNames = $p.PrinterPaperNames; `+
		`paperSizes = $p.PaperSizes; `+
		`colorSupported = $p.ColorSupported; `+
		`duplexSupported = $p.DuplexSupported; `+
		`driverName = $p.DriverName; `+
		`portName = $p.PortName; `+
		`printProcessor = $p.PrintProcessor; `+
		`deviceId = $p.DeviceID; `+
		`config = @{ `+
		`paperSize = $c.PaperSize; `+
		`orientation = $c.Orientation; `+
		`color = $c.Color; `+
		`duplex = $c.Duplex; `+
		`copies = $c.Copies `+
		`} `+
		`} | ConvertTo-Json -Depth 4`, escaped, escaped)

	cmd := exec.Command("powershell", "-NoProfile", "-NonInteractive", "-Command", ps)
	cmd.SysProcAttr = &syscall.SysProcAttr{HideWindow: true}
	output, err := cmd.Output()
	if err != nil {
		return nil, fmt.Errorf("get printer capabilities failed: %v", err)
	}

	decoded, err := decodeCmdOutput(output)
	if err != nil {
		decoded = string(output)
	}

	var caps map[string]interface{}
	if err := json.Unmarshal([]byte(decoded), &caps); err != nil {
		return nil, fmt.Errorf("parse printer capabilities failed: %v", err)
	}

	return caps, nil
}

func (b *Bridge) printPDFPlatform(printerName, filePath string, options PrintOptions) error {
	sumatraPath, err := findSumatraPDF()
	if err != nil {
		return err
	}

	settings := buildSumatraPrintSettings(options)

	args := []string{"-print-to", printerName}
	if settings != "" {
		args = append(args, "-print-settings", settings)
	}
	args = append(args, filePath)

	cmd := exec.Command(sumatraPath, args...)
	cmd.SysProcAttr = &syscall.SysProcAttr{HideWindow: true}

	queueSnapshot, _ := getPrintJobIDs(printerName)
	if err := cmd.Start(); err != nil {
		return fmt.Errorf("sumatra print failed to start: %v", err)
	}

	cmdDone := make(chan error, 1)
	go func() {
		cmdDone <- cmd.Wait()
	}()

	if err := waitForWindowsPrintCompletion(printerName, queueSnapshot, cmdDone); err != nil {
		return err
	}

	return nil
}

type windowsPrintJob struct {
	Id           int         `json:"Id"`
	JobStatus    interface{} `json:"JobStatus"`
	DocumentName string      `json:"DocumentName"`
}

const (
	printQueuePollInterval    = 500 * time.Millisecond
	printQueueAppearTimeout   = 120 * time.Second
	printQueueCompleteTimeout = 5 * time.Minute
)

func getPrintJobs(printerName string) ([]windowsPrintJob, error) {
	printerName = strings.TrimSpace(printerName)
	if printerName == "" {
		return nil, fmt.Errorf("printer name is empty")
	}

	escaped := strings.ReplaceAll(printerName, "'", "''")
	ps := fmt.Sprintf(`Get-PrintJob -PrinterName '%s' | Select-Object Id,JobStatus,DocumentName | ConvertTo-Json -Depth 3`, escaped)
	cmd := exec.Command("powershell", "-NoProfile", "-NonInteractive", "-Command", ps)
	cmd.SysProcAttr = &syscall.SysProcAttr{HideWindow: true}
	output, err := cmd.Output()
	if err != nil {
		return nil, err
	}

	decoded, err := decodeCmdOutput(output)
	if err != nil {
		decoded = string(output)
	}
	decoded = strings.TrimSpace(decoded)
	if decoded == "" || decoded == "null" {
		return nil, nil
	}

	var list []windowsPrintJob
	if err := json.Unmarshal([]byte(decoded), &list); err == nil {
		return list, nil
	}

	var single windowsPrintJob
	if err := json.Unmarshal([]byte(decoded), &single); err != nil {
		return nil, err
	}
	return []windowsPrintJob{single}, nil
}

func getPrintJobIDs(printerName string) (map[int]bool, error) {
	jobs, err := getPrintJobs(printerName)
	if err != nil {
		return nil, err
	}
	ids := make(map[int]bool, len(jobs))
	for _, job := range jobs {
		if job.Id > 0 {
			ids[job.Id] = true
		}
	}
	return ids, nil
}

func waitForWindowsPrintCompletion(printerName string, existingIDs map[int]bool, cmdDone <-chan error) error {
	appearDeadline := time.Now().Add(printQueueAppearTimeout)
	completeDeadline := time.Now().Add(printQueueCompleteTimeout)

	queued := false
	jobID := 0
	sumatraDone := false

	for {
		select {
		case err := <-cmdDone:
			sumatraDone = true
			if err != nil && !queued {
				return fmt.Errorf("sumatra print failed: %v", err)
			}
			// Sumatra 已正常退出且 spooler 未出现新任务：部分驱动/打印机直接出纸，不经过队列
			if err == nil && !queued {
				return nil
			}
		default:
		}

		now := time.Now()
		if !queued && sumatraDone {
			return nil
		}
		if !queued && now.After(appearDeadline) {
			return fmt.Errorf("print job not queued within %s", printQueueAppearTimeout)
		}
		if queued && now.After(completeDeadline) {
			return fmt.Errorf("print job not completed within %s", printQueueCompleteTimeout)
		}

		jobs, err := getPrintJobs(printerName)
		if err == nil {
			if !queued {
				for _, job := range jobs {
					if !existingIDs[job.Id] {
						jobID = job.Id
						queued = true
						break
					}
				}
			} else {
				found := false
				var statusList []string
				for _, job := range jobs {
					if job.Id == jobID {
						found = true
						statusList = normalizeJobStatus(job.JobStatus)
						break
					}
				}
				if !found {
					return nil
				}
				if isWindowsJobFailed(statusList) {
					return fmt.Errorf("print job failed: %s", strings.Join(statusList, ", "))
				}
			}
		}

		time.Sleep(printQueuePollInterval)
	}
}

func normalizeJobStatus(status interface{}) []string {
	switch v := status.(type) {
	case string:
		if strings.TrimSpace(v) == "" {
			return nil
		}
		return []string{strings.TrimSpace(v)}
	case []interface{}:
		out := make([]string, 0, len(v))
		for _, item := range v {
			if s, ok := item.(string); ok {
				if strings.TrimSpace(s) != "" {
					out = append(out, strings.TrimSpace(s))
				}
			}
		}
		return out
	default:
		return nil
	}
}

func isWindowsJobFailed(statuses []string) bool {
	for _, status := range statuses {
		value := strings.ToLower(status)
		if strings.Contains(value, "error") || strings.Contains(value, "offline") || strings.Contains(value, "paused") {
			return true
		}
	}
	return false
}

func findSumatraPDF() (string, error) {
	if envPath := strings.TrimSpace(os.Getenv("SUMATRAPDF_PATH")); envPath != "" {
		if fileExists(envPath) {
			return envPath, nil
		}
	}

	if exe, err := os.Executable(); err == nil {
		candidate := filepath.Join(filepath.Dir(exe), "SumatraPDF.exe")
		if fileExists(candidate) {
			return candidate, nil
		}
	}

	if path, err := exec.LookPath("SumatraPDF.exe"); err == nil {
		return path, nil
	}
	if path, err := exec.LookPath("SumatraPDF"); err == nil {
		return path, nil
	}

	return "", fmt.Errorf("SumatraPDF.exe not found. Place it next to the app, add it to PATH, or set SUMATRAPDF_PATH")
}

func fileExists(path string) bool {
	info, err := os.Stat(path)
	return err == nil && !info.IsDir()
}

func buildSumatraPrintSettings(options PrintOptions) string {
	var settings []string

	if options.PageRange != "" {
		settings = append(settings, options.PageRange)
	}

	switch strings.ToLower(strings.TrimSpace(options.PageSet)) {
	case "even":
		settings = append(settings, "even")
	case "odd":
		settings = append(settings, "odd")
	}

	switch strings.ToLower(strings.TrimSpace(options.Scale)) {
	case "fit":
		settings = append(settings, "fit")
	case "shrink":
		settings = append(settings, "shrink")
	case "none", "actual", "noscale":
		settings = append(settings, "noscale")
	}

	switch strings.ToLower(strings.TrimSpace(options.Orientation)) {
	case "portrait":
		settings = append(settings, "portrait")
	case "landscape":
		settings = append(settings, "landscape")
	}

	switch strings.ToLower(strings.TrimSpace(options.Duplex)) {
	case "simplex", "one-sided":
		settings = append(settings, "simplex")
	case "long-edge", "long", "duplex", "duplexlong":
		settings = append(settings, "duplex")
	case "short-edge", "short", "duplexshort":
		settings = append(settings, "duplexshort")
	}

	switch strings.ToLower(strings.TrimSpace(options.ColorMode)) {
	case "color":
		settings = append(settings, "color")
	case "mono", "monochrome", "grayscale", "gray":
		settings = append(settings, "monochrome")
	}

	if options.Paper != "" {
		settings = append(settings, fmt.Sprintf("paper=%s", options.Paper))
	}

	if options.TrayBin != "" {
		settings = append(settings, fmt.Sprintf("bin=%s", options.TrayBin))
	}

	if options.Copies > 1 {
		settings = append(settings, fmt.Sprintf("%dx", options.Copies))
	}

	return strings.Join(settings, ",")
}