//go:build windows

package gpu

import (
	"log"
	"os/exec"
	"strings"
)

type gpuName struct {
	Name   string
	Vendor string
}

func detectGPUNames() []gpuName {
	// Try PowerShell first, then wmic
	gpus := psGPUList()
	if len(gpus) > 0 {
		log.Printf("[gpu] PowerShell found %d GPUs", len(gpus))
		for _, g := range gpus {
			log.Printf("[gpu]   %s -> vendor=%s", g.Name, g.Vendor)
		}
		return gpus
	}

	gpus = wmicGPUList()
	if len(gpus) > 0 {
		log.Printf("[gpu] WMIC found %d GPUs", len(gpus))
		for _, g := range gpus {
			log.Printf("[gpu]   %s -> vendor=%s", g.Name, g.Vendor)
		}
		return gpus
	}

	log.Printf("[gpu] No GPUs detected via PowerShell or WMIC")
	return nil
}

func psGPUList() []gpuName {
	out, err := exec.Command("powershell", "-NoProfile", "-Command",
		"Get-CimInstance Win32_VideoController | Select-Object Name,AdapterCompatibility,DriverVersion | ConvertTo-Csv -NoTypeInformation",
	).CombinedOutput()
	log.Printf("[gpu] PS output:\n%s", string(out))
	if err != nil {
		log.Printf("[gpu] PS error: %v", err)
		return nil
	}
	return parseCSV(string(out))
}

func wmicGPUList() []gpuName {
	out, err := exec.Command("wmic", "path", "win32_VideoController",
		"get", "Name,AdapterCompatibility", "/format:csv").CombinedOutput()
	log.Printf("[gpu] WMIC output:\n%s", string(out))
	if err != nil {
		log.Printf("[gpu] WMIC error: %v", err)
		return nil
	}
	return parseWMIC(string(out))
}

func parseCSV(out string) []gpuName {
	var gpus []gpuName
	seen := map[string]bool{}
	lines := strings.Split(out, "\n")
	for _, line := range lines {
		line = strings.TrimSpace(line)
		if line == "" || strings.HasPrefix(line, "\"Name\"") || strings.HasPrefix(line, "Name") {
			continue
		}
		// Remove quotes: "Name","AdapterCompatibility"
		line = strings.ReplaceAll(line, "\"", "")
		parts := strings.SplitN(line, ",", 2)
		if len(parts) < 1 {
			continue
		}
		name := strings.TrimSpace(parts[0])
		vendor := ""
		if len(parts) >= 2 {
			vendor = strings.TrimSpace(parts[1])
		}
		if name == "" || seen[name] {
			continue
		}
		if isVirtualGPU(name) {
			log.Printf("[gpu] SKIP virtual: %s", name)
			continue
		}
		vendor = classifyVendor(vendor, name)
		if vendor == "unknown" {
			log.Printf("[gpu] SKIP unknown vendor (vendor=%q name=%q)", vendor, name)
			continue
		}
		seen[name] = true
		gpus = append(gpus, gpuName{Name: name, Vendor: vendor})
	}
	return gpus
}

func parseWMIC(out string) []gpuName {
	var gpus []gpuName
	seen := map[string]bool{}
	lines := strings.Split(out, "\n")
	for _, line := range lines {
		line = strings.TrimSpace(line)
		if line == "" || strings.HasPrefix(line, "Node,") {
			continue
		}
		parts := strings.SplitN(line, ",", 3)
		if len(parts) < 3 {
			continue
		}
		name := strings.TrimSpace(parts[2])
		vendor := strings.TrimSpace(parts[1])
		if name == "" || seen[name] {
			continue
		}
		if isVirtualGPU(name) {
			log.Printf("[gpu] SKIP virtual: %s", name)
			continue
		}
		vendor = classifyVendor(vendor, name)
		if vendor == "unknown" {
			log.Printf("[gpu] SKIP unknown vendor (vendor=%q name=%q)", vendor, name)
			continue
		}
		seen[name] = true
		gpus = append(gpus, gpuName{Name: name, Vendor: vendor})
	}
	return gpus
}

func classifyVendor(vendor, name string) string {
	lower := strings.ToLower(vendor + " " + name)
	switch {
	case strings.Contains(lower, "nvidia"):
		return "nvidia"
	case strings.Contains(lower, "intel") || strings.Contains(lower, "uhd graphics") ||
		strings.Contains(lower, "iris") || strings.Contains(lower, "hd graphics"):
		return "intel"
	case strings.Contains(lower, "amd") || strings.Contains(lower, "radeon") || strings.Contains(lower, "ati"):
		return "amd"
	default:
		return "unknown"
	}
}

func isVirtualGPU(name string) bool {
	lower := strings.ToLower(name)
	// Filter out virtual/remote/display-only adapters that don't have encoders
	virtual := []string{
		"virtual", "remote", "rdp", "citrix", "vmware", "hyper-v",
		"mirror", "indirect", "parsec", "splashtop", "idm",
		"mirage", "vnc", "displayonly", "basicdisplay",
		"microsoft basic", "microsoft remote",
	}
	for _, v := range virtual {
		if strings.Contains(lower, v) {
			return true
		}
	}
	return false
}