package nvidia

import (
	"encoding/json"
	"regexp"
	"strconv"
	"strings"

	"git.mchus.pro/mchus/logpile/internal/models"
	"git.mchus.pro/mchus/logpile/internal/parser"
)

var (
	gpuNameWithSerialRegex = regexp.MustCompile(`^SXM(\d+)_SN_(.+)$`)
	gpuNameSlotOnlyRegex   = regexp.MustCompile(`^SXM(\d+)$`)
	skuCodeRegex           = regexp.MustCompile(`^(G\d{3})[.-](\d{4})`)
	skuCodeInsideRegex     = regexp.MustCompile(`(?:^|[^A-Z0-9])(?:\d)?(G\d{3})[.-](\d{4})(?:[^A-Z0-9]|$)`)
	inforomPathRegex       = regexp.MustCompile(`(?i)(?:^|[\\/])(checkinforom|inforom)[\\/](SXM(\d+))(?:_SN_([^\\/]+))?[\\/]fieldiag\.jso$`)
	inforomProductPNRegex  = regexp.MustCompile(`"product_part_num"\s*:\s*"([^"]+)"`)
	inforomSerialRegex     = regexp.MustCompile(`"serial_number"\s*:\s*"([^"]+)"`)
)

type testSpecData struct {
	Actions []struct {
		VirtualID string `json:"virtual_id"`
		Args      struct {
			SKUToFile   map[string]string          `json:"sku_to_sku_json_file_map"`
			ModsMapping map[string]json.RawMessage `json:"mods_mapping"`
		} `json:"args"`
	} `json:"actions"`
}

type inventoryFieldDiagSummary struct {
	ModsRuns []struct {
		ModsHeader []struct {
			GPUName   string `json:"GpuName"`
			BoardInfo string `json:"BoardInfo"`
		} `json:"ModsHeader"`
	} `json:"ModsRuns"`
}

var hardcodedSKUToFileMap = map[string]string{
	"G520-0200": "sku_hgx-h100-8-gpu_80g_aircooled_field.json",
	"G520-0201": "sku_hgx-h100-8-gpu_80g_aircooled_field.json",
	"G520-0202": "sku_hgx-h100-8-gpu_80g_tpol_field.json",
	"G520-0203": "sku_hgx-h100-8-gpu_80g_tpol_field.json",
	"G520-0205": "sku_hgx-h800-8-gpu_80g_aircooled_field.json",
	"G520-0207": "sku_hgx-h800-8-gpu_80g_tpol_field.json",
	"G520-0221": "sku_hgx-h100-8-gpu_96g_aircooled_field.json",
	"G520-0236": "sku_hgx-h20-8-gpu_96g_aircooled_field.json",
	"G520-0238": "sku_hgx-h20-8-gpu_96g_tpol_field.json",
	"G520-0266": "sku_hgx-h20-8-gpu_141g_aircooled_field.json",
	"G520-0280": "sku_hgx-h200-8-gpu_141g_aircooled_field.json",
	"G520-0282": "sku_hgx-h200-8-gpu_141g_tpol_field.json",
	"G520-0292": "sku_hgx-h100-8-gpu_sku_292_field.json",
}

// ApplyGPUModelsFromSKU updates GPU model names using SKU mapping from testspec.json.
// Mapping source:
// - inventory/fieldiag_summary.json: GPUName -> BoardInfo(SKU)
// - hardcoded SKU mapping
// - testspec.json: SKU -> sku_hgx-... filename (fallback for unknown hardcoded SKU)
// - inforom/*/fieldiag.jso: product_part_num (full P/N with embedded SKU)
// - testspec.json gpu_fieldiag.mods_mapping: DeviceID -> GPU generation (last fallback for description)
func ApplyGPUModelsFromSKU(files []parser.ExtractedFile, result *models.AnalysisResult) {
	if result == nil || result.Hardware == nil || len(result.Hardware.GPUs) == 0 {
		return
	}

	skuToFile := parseSKUToFileMap(files)
	generationByDeviceID := parseGenerationByDeviceID(files)

	serialToSKU, slotToSKU, serialToPartNumber, slotToPartNumber := parseGPUSKUMapping(files)

	for i := range result.Hardware.GPUs {
		gpu := &result.Hardware.GPUs[i]
		slot := strings.TrimSpace(gpu.Slot)
		serial := strings.TrimSpace(gpu.SerialNumber)

		if gpu.PartNumber == "" && serial != "" {
			if pn := strings.TrimSpace(serialToPartNumber[serial]); pn != "" {
				gpu.PartNumber = pn
			}
		}
		if gpu.PartNumber == "" {
			if pn := strings.TrimSpace(slotToPartNumber[slot]); pn != "" {
				gpu.PartNumber = pn
			}
		}

		if partNumber := strings.TrimSpace(gpu.PartNumber); partNumber != "" {
			gpu.Model = partNumber
		}

		sku := extractSKUFromPartNumber(gpu.PartNumber)
		if sku == "" && serial != "" {
			sku = serialToSKU[serial]
		}
		if sku == "" {
			sku = slotToSKU[slot]
		}
		if sku != "" {
			if desc := resolveDescriptionFromSKU(sku, skuToFile); desc != "" {
				gpu.Description = desc
				continue
			}
		}

		if gen := resolveGenerationDescription(gpu.DeviceID, generationByDeviceID); gen != "" {
			gpu.Description = gen
		}
	}
}

func parseSKUToFileMap(files []parser.ExtractedFile) map[string]string {
	result := make(map[string]string, len(hardcodedSKUToFileMap))
	for sku, file := range hardcodedSKUToFileMap {
		result[normalizeSKUCode(sku)] = strings.TrimSpace(file)
	}

	specFile := parser.FindFileByName(files, "testspec.json")
	if specFile == nil {
		return result
	}

	var spec testSpecData
	if err := json.Unmarshal(specFile.Content, &spec); err != nil {
		return result
	}

	for _, action := range spec.Actions {
		for sku, file := range action.Args.SKUToFile {
			normSKU := normalizeSKUCode(sku)
			if normSKU == "" {
				continue
			}
			// Priority: hardcoded mapping wins, testspec extends unknown SKU list.
			if _, exists := result[normSKU]; !exists {
				result[normSKU] = strings.TrimSpace(file)
			}
		}
	}
	return result
}

func parseGenerationByDeviceID(files []parser.ExtractedFile) map[string]string {
	specFile := parser.FindFileByName(files, "testspec.json")
	if specFile == nil {
		return nil
	}

	var spec testSpecData
	if err := json.Unmarshal(specFile.Content, &spec); err != nil {
		return nil
	}

	familyToGeneration := make(map[string]string)
	deviceToGeneration := make(map[string]string)

	for _, action := range spec.Actions {
		if strings.TrimSpace(strings.ToLower(action.VirtualID)) != "gpu_fieldiag" {
			continue
		}
		for key, raw := range action.Args.ModsMapping {
			if strings.HasPrefix(key, "#mods.") {
				family := strings.TrimSpace(strings.TrimPrefix(key, "#mods."))
				if family == "" {
					continue
				}
				var generation string
				if err := json.Unmarshal(raw, &generation); err == nil {
					generation = strings.TrimSpace(generation)
					if generation != "" {
						familyToGeneration[family] = generation
					}
				}
			}
		}

		for key, raw := range action.Args.ModsMapping {
			family := strings.TrimSpace(key)
			if family == "" || strings.HasPrefix(family, "#") {
				continue
			}
			generation := strings.TrimSpace(familyToGeneration[family])
			if generation == "" {
				continue
			}
			var deviceIDs []string
			if err := json.Unmarshal(raw, &deviceIDs); err != nil {
				continue
			}
			for _, id := range deviceIDs {
				norm := normalizeDeviceIDHex(id)
				if norm != "" {
					deviceToGeneration[norm] = generation
				}
			}
		}
	}

	return deviceToGeneration
}

func parseGPUSKUMapping(files []parser.ExtractedFile) (map[string]string, map[string]string, map[string]string, map[string]string) {
	serialToSKU := make(map[string]string)
	slotToSKU := make(map[string]string)
	serialToPartNumber := make(map[string]string)
	slotToPartNumber := make(map[string]string)

	// 1) inventory/fieldiag_summary.json mapping (GPUName/BoardInfo).
	var summaryFile *parser.ExtractedFile
	for _, f := range files {
		path := strings.ToLower(f.Path)
		if strings.Contains(path, "inventory/fieldiag_summary.json") ||
			strings.Contains(path, "inventory\\fieldiag_summary.json") {
			summaryFile = &f
			break
		}
	}
	if summaryFile == nil {
		// Continue: inforom may still contain usable part numbers.
	} else {
		var summaries []inventoryFieldDiagSummary
		if err := json.Unmarshal(summaryFile.Content, &summaries); err == nil {
			for _, summary := range summaries {
				addSummaryMapping(summary, serialToSKU, slotToSKU)
			}
		} else {
			var summary inventoryFieldDiagSummary
			if err := json.Unmarshal(summaryFile.Content, &summary); err == nil {
				addSummaryMapping(summary, serialToSKU, slotToSKU)
			}
		}
	}

	// 2) inforom/checkinforom fieldiag.jso mapping (full product_part_num).
	for _, f := range files {
		path := strings.TrimSpace(f.Path)
		m := inforomPathRegex.FindStringSubmatch(path)
		if len(m) == 0 {
			continue
		}

		slot := "GPU" + strings.ToUpper(strings.TrimSpace(m[2])) // SXM7 -> GPUSXM7
		serialFromPath := strings.TrimSpace(m[4])

		productPNMatch := inforomProductPNRegex.FindSubmatch(f.Content)
		if len(productPNMatch) == 2 {
			partNumber := strings.TrimSpace(string(productPNMatch[1]))
			if partNumber != "" {
				slotToPartNumber[slot] = partNumber
				if serialFromPath != "" {
					serialToPartNumber[serialFromPath] = partNumber
				}
				if sku := extractSKUFromPartNumber(partNumber); sku != "" {
					slotToSKU[slot] = sku
					if serialFromPath != "" {
						serialToSKU[serialFromPath] = sku
					}
				}
			}
		}

		serialMatch := inforomSerialRegex.FindSubmatch(f.Content)
		if len(serialMatch) == 2 {
			serial := strings.TrimSpace(string(serialMatch[1]))
			if serial != "" {
				if sku := slotToSKU[slot]; sku != "" {
					serialToSKU[serial] = sku
				}
				if pn := slotToPartNumber[slot]; pn != "" {
					serialToPartNumber[serial] = pn
				}
			}
		}
	}

	return serialToSKU, slotToSKU, serialToPartNumber, slotToPartNumber
}

func addSummaryMapping(summary inventoryFieldDiagSummary, serialToSKU map[string]string, slotToSKU map[string]string) {
	for _, run := range summary.ModsRuns {
		for _, h := range run.ModsHeader {
			sku := normalizeSKUCode(h.BoardInfo)
			if sku == "" {
				continue
			}

			gpuName := strings.TrimSpace(h.GPUName)
			if matches := gpuNameWithSerialRegex.FindStringSubmatch(gpuName); len(matches) == 3 {
				slotToSKU["GPUSXM"+matches[1]] = sku
				serialToSKU[strings.TrimSpace(matches[2])] = sku
				continue
			}
			if matches := gpuNameSlotOnlyRegex.FindStringSubmatch(gpuName); len(matches) == 2 {
				slotToSKU["GPUSXM"+matches[1]] = sku
			}
		}
	}
}

func resolveDescriptionFromSKU(sku string, skuToFile map[string]string) string {
	file := strings.ToLower(strings.TrimSpace(skuToFile[normalizeSKUCode(sku)]))
	if file == "" {
		return ""
	}

	return skuFilenameToDescription(file)
}

func normalizeSKUCode(v string) string {
	s := strings.TrimSpace(strings.ToUpper(v))
	if s == "" {
		return ""
	}

	if m := skuCodeRegex.FindStringSubmatch(s); len(m) == 3 {
		return m[1] + "-" + m[2]
	}

	return s
}

func extractSKUFromPartNumber(partNumber string) string {
	s := strings.TrimSpace(strings.ToUpper(partNumber))
	if s == "" {
		return ""
	}

	if m := skuCodeInsideRegex.FindStringSubmatch(s); len(m) == 3 {
		return m[1] + "-" + m[2]
	}

	return ""
}

func skuFilenameToDescription(file string) string {
	s := strings.TrimSpace(strings.ToLower(file))
	if s == "" {
		return ""
	}

	s = strings.TrimSuffix(s, ".json")
	s = strings.TrimSuffix(s, "_field")
	s = strings.TrimPrefix(s, "sku_")
	s = strings.ReplaceAll(s, "-", " ")
	s = strings.ReplaceAll(s, "_", " ")
	s = strings.Join(strings.Fields(s), " ")

	return strings.TrimSpace(s)
}

func resolveGenerationDescription(deviceID int, deviceToGeneration map[string]string) string {
	if deviceID <= 0 || len(deviceToGeneration) == 0 {
		return ""
	}
	return strings.TrimSpace(deviceToGeneration[normalizeDeviceIDHex(strconv.FormatInt(int64(deviceID), 16))])
}

func normalizeDeviceIDHex(v string) string {
	s := strings.TrimSpace(strings.ToLower(v))
	s = strings.TrimPrefix(s, "0x")
	if s == "" {
		return ""
	}

	n, err := strconv.ParseUint(s, 16, 32)
	if err != nil {
		return ""
	}

	return "0x" + strings.ToLower(strconv.FormatUint(n, 16))
}