package nvidia

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

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

var (
	gpuNameWithSerialRegex = regexp.MustCompile(`^SXM(\d+)_SN_(.+)$`)
	gpuNameSlotOnlyRegex   = regexp.MustCompile(`^SXM(\d+)$`)
	skuModelRegex          = regexp.MustCompile(`sku_hgx-([a-z0-9]+)-\d+-gpu`)
	skuCodeRegex           = regexp.MustCompile(`^(G\d{3})[.-](\d{4})`)
)

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

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

// ApplyGPUModelsFromSKU updates GPU model names using SKU mapping from testspec.json.
// Mapping source:
// - inventory/fieldiag_summary.json: GPUName -> BoardInfo(SKU)
// - testspec.json: SKU -> sku_hgx-... filename
func ApplyGPUModelsFromSKU(files []parser.ExtractedFile, result *models.AnalysisResult) {
	if result == nil || result.Hardware == nil || len(result.Hardware.GPUs) == 0 {
		return
	}

	skuToFile := parseSKUToFileMap(files)
	if len(skuToFile) == 0 {
		return
	}

	serialToSKU, slotToSKU := parseGPUSKUMapping(files)
	if len(serialToSKU) == 0 && len(slotToSKU) == 0 {
		return
	}

	for i := range result.Hardware.GPUs {
		gpu := &result.Hardware.GPUs[i]
		sku := ""

		if serial := strings.TrimSpace(gpu.SerialNumber); serial != "" {
			sku = serialToSKU[serial]
		}
		if sku == "" {
			sku = slotToSKU[strings.TrimSpace(gpu.Slot)]
		}
		if sku == "" {
			continue
		}

		model := resolveModelFromSKU(sku, skuToFile)
		if model == "" {
			continue
		}

		gpu.Model = model
	}
}

func parseSKUToFileMap(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
	}

	result := make(map[string]string)
	for _, action := range spec.Actions {
		for sku, file := range action.Args.SKUToFile {
			normSKU := normalizeSKUCode(sku)
			if normSKU == "" {
				continue
			}
			result[normSKU] = strings.TrimSpace(file)
		}
	}
	return result
}

func parseGPUSKUMapping(files []parser.ExtractedFile) (map[string]string, map[string]string) {
	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 {
		return nil, nil
	}

	var summary inventoryFieldDiagSummary
	if err := json.Unmarshal(summaryFile.Content, &summary); err != nil {
		return nil, nil
	}

	serialToSKU := make(map[string]string)
	slotToSKU := make(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
			}
		}
	}

	return serialToSKU, slotToSKU
}

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

	m := skuModelRegex.FindStringSubmatch(file)
	if len(m) != 2 {
		return ""
	}

	gpuFamily := strings.ToUpper(strings.TrimSpace(m[1]))
	if gpuFamily == "" {
		return ""
	}

	return fmt.Sprintf("NVIDIA %s SXM", gpuFamily)
}

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
}