//go:build windows

package handlers

import (
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"syscall"
)

// installKneronWinUSBDriverHandler 呼叫 KneronPLUS SDK 的 libwdi wrapper 安裝 WinUSB driver。
//
// 實作參考 edge-ai-platform installer/platform_windows.go 的 installKneronDriverViaSDK：
//   - 組 Python script 呼叫 kp.core.install_driver_for_windows(pid) 對三種 PID
//   - PowerShell Start-Process -Verb RunAs 提權（libwdi 要求 admin）
//   - 結果寫到 temp file 讓 Go 讀回來
func installKneronWinUSBDriverHandler(pythonBin string) error {
	if _, err := os.Stat(pythonBin); err != nil {
		return fmt.Errorf("python interpreter not found at %s: %w", pythonBin, err)
	}

	resultPath := filepath.Join(os.TempDir(), "visiona-local-driver-result.txt")
	_ = os.Remove(resultPath)

	// venv 根目錄
	venvRoot := filepath.Dir(filepath.Dir(pythonBin))

	// Python script:
	//  1. 對三種 PID 呼叫 kp.core.install_driver_for_windows
	//  2. 安裝完立刻 scan_devices() 驗證，看 SDK 能不能開 handle
	//  3. 不 swallow exception — 把 traceback 完整寫到 result 檔
	pyScript := fmt.Sprintf(`
import sys, os, traceback
result_path = r'%s'
lines = []
def out(msg):
    lines.append(str(msg))
    try:
        sys.stdout.write(str(msg) + '\n'); sys.stdout.flush()
    except Exception:
        pass
try:
    kp_lib = os.path.join(r'%s', 'Lib', 'site-packages', 'kp', 'lib')
    if os.path.isdir(kp_lib):
        os.environ['PATH'] = kp_lib + ';' + os.environ.get('PATH', '')
        try:
            os.add_dll_directory(kp_lib)
        except Exception as dle:
            out(f"WARN: add_dll_directory failed: {dle}")
    import kp
    out(f"kp module imported: {kp.__file__}")
    for pid in [kp.ProductId.KP_DEVICE_KL520, kp.ProductId.KP_DEVICE_KL720, kp.ProductId.KP_DEVICE_KL720_LEGACY]:
        try:
            out(f"Installing driver for {pid.name} (value={pid.value})...")
            kp.core.install_driver_for_windows(pid)
            out(f"  OK: {pid.name}")
        except Exception as e:
            out(f"  SKIP: {pid.name}: {type(e).__name__}: {e}")
    # 驗證：裝完立刻 scan + 印 is_connectable
    out("Verifying with scan_devices()...")
    try:
        descs = kp.core.scan_devices()
        out(f"  found {descs.device_descriptor_number} Kneron device(s)")
        for i in range(descs.device_descriptor_number):
            d = descs.device_descriptor_list[i]
            out(f"  [{i}] pid=0x{d.product_id:04X} usb_port={d.usb_port_id} connectable={d.is_connectable} fw={d.firmware}")
    except Exception as se:
        out(f"  scan_devices failed: {type(se).__name__}: {se}")
    out("DONE")
except ImportError as e:
    out(f"ERROR: kp module not available: {e}")
    out(traceback.format_exc())
except Exception as e:
    out(f"ERROR: {type(e).__name__}: {e}")
    out(traceback.format_exc())
finally:
    try:
        with open(result_path, 'w', encoding='utf-8') as f:
            f.write('\n'.join(lines))
    except Exception:
        pass
`, resultPath, venvRoot)

	scriptPath := filepath.Join(os.TempDir(), "visiona-local-install-usb-driver.py")
	if err := os.WriteFile(scriptPath, []byte(pyScript), 0o644); err != nil {
		return fmt.Errorf("write driver install script: %w", err)
	}
	defer os.Remove(scriptPath)

	elevateCmd := fmt.Sprintf(
		`Start-Process -FilePath '%s' -ArgumentList '"%s"' -Verb RunAs -Wait -WindowStyle Hidden`,
		pythonBin, scriptPath,
	)
	cmd := exec.Command("powershell", "-NoProfile", "-ExecutionPolicy", "Bypass", "-Command", elevateCmd)
	cmd.SysProcAttr = &syscall.SysProcAttr{HideWindow: true, CreationFlags: 0x08000000}
	if out, err := cmd.CombinedOutput(); err != nil {
		return fmt.Errorf("driver 安裝需要系統管理員權限（UAC 可能被拒絕）：%s", strings.TrimSpace(string(out)))
	}

	resultData, err := os.ReadFile(resultPath)
	_ = os.Remove(resultPath)
	if err != nil {
		return fmt.Errorf("driver 安裝已執行但無法讀取結果，請在裝置管理員確認或用 Zadig 手動安裝 https://zadig.akeo.ie/")
	}

	result := strings.TrimSpace(string(resultData))
	// 把完整結果印到 server stderr 方便使用者 / 我們 debug
	fmt.Fprintln(os.Stderr, "=== Kneron driver install result ===")
	fmt.Fprintln(os.Stderr, result)
	fmt.Fprintln(os.Stderr, "=== end ===")

	if strings.Contains(result, "ERROR:") {
		return fmt.Errorf("driver 安裝失敗（完整訊息見 server.stderr.log）：%s", firstLines(result, 6))
	}

	// 檢查 DONE 標記 + 至少一個 OK
	if !strings.Contains(result, "DONE") {
		return fmt.Errorf("driver 安裝未完成（沒有 DONE 標記，見 server.stderr.log）：%s", firstLines(result, 6))
	}
	if !strings.Contains(result, "OK:") {
		return fmt.Errorf("driver 安裝全部失敗，沒有任何 PID 成功（見 server.stderr.log）：%s", firstLines(result, 10))
	}

	return nil
}

// firstLines 取結果的前 n 行，避免 error message 過長
func firstLines(s string, n int) string {
	lines := strings.Split(s, "\n")
	if len(lines) > n {
		lines = lines[:n]
		lines = append(lines, "...")
	}
	return strings.Join(lines, " | ")
}