package inspur

import (
	"fmt"
	"regexp"
	"strconv"
	"strings"

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

type hgxGPUAssemblyInfo struct {
	Model  string
	Part   string
	Serial string
}

type hgxGPUFirmwareInfo struct {
	Firmware string
	InfoROM  string
}

type hgxFirmwareInventoryEntry struct {
	ID              string
	Version         string
	ActiveVersion   string
	InactiveVersion string
}

// Logical GPU index mapping used by HGX B200 UI ordering.
// Example from real logs/UI:
// GPU0->SXM5, GPU1->SXM7, GPU2->SXM6, GPU3->SXM8, GPU4->SXM2, GPU5->SXM4, GPU6->SXM3, GPU7->SXM1.
var hgxLogicalToSXM = map[int]int{
	0: 5,
	1: 7,
	2: 6,
	3: 8,
	4: 2,
	5: 4,
	6: 3,
	7: 1,
}

var (
	reHGXGPUBlock = regexp.MustCompile(`(?s)/redfish/v1/Chassis/HGX_GPU_SXM_(\d+)/Assembly.*?"Name":\s*"GPU Board Assembly".*?"Model":\s*"([^"]+)".*?"PartNumber":\s*"([^"]+)".*?"SerialNumber":\s*"([^"]+)"`)
	reHGXFWBlock  = regexp.MustCompile(`(?s)"Id":\s*"HGX_FW_GPU_SXM_(\d+)".*?"Version":\s*"([^"]*)"`)
	reHGXInfoROM  = regexp.MustCompile(`(?s)"Id":\s*"HGX_InfoROM_GPU_SXM_(\d+)".*?"Version":\s*"([^"]*)"`)
	reIDLine      = regexp.MustCompile(`"Id":\s*"([^"]+)"`)
	reVersion     = regexp.MustCompile(`"Version":\s*"([^"]*)"`)
	reSlotGPU     = regexp.MustCompile(`(?i)gpu\s*#?\s*(\d+)`)
)

func enrichGPUsFromHGXHWInfo(content []byte, hw *models.HardwareConfig) {
	if hw == nil || len(hw.GPUs) == 0 || len(content) == 0 {
		return
	}

	bySXM := parseHGXGPUAssembly(content)
	if len(bySXM) == 0 {
		return
	}
	fwBySXM := parseHGXGPUFirmware(content)

	normalizeHGXGPUInventory(hw, bySXM)

	for i := range hw.GPUs {
		gpu := &hw.GPUs[i]
		logicalIdx, ok := extractLogicalGPUIndex(gpu.Slot)
		if !ok {
			// Keep existing info if slot index cannot be determined.
			continue
		}

		sxm := resolveSXMIndex(logicalIdx, bySXM)
		info, found := bySXM[sxm]
		if !found {
			continue
		}

		if strings.TrimSpace(gpu.SerialNumber) == "" {
			gpu.SerialNumber = info.Serial
		}
		if shouldReplaceGPUModel(gpu.Model) {
			gpu.Model = info.Model
		}
		if strings.TrimSpace(gpu.PartNumber) == "" {
			gpu.PartNumber = info.Part
		}
		if strings.TrimSpace(gpu.Manufacturer) == "" {
			gpu.Manufacturer = "NVIDIA"
		}
		if fw, ok := fwBySXM[sxm]; ok {
			if strings.TrimSpace(gpu.Firmware) == "" && strings.TrimSpace(fw.Firmware) != "" {
				gpu.Firmware = fw.Firmware
			}
			if strings.TrimSpace(gpu.VideoBIOS) == "" && strings.TrimSpace(fw.InfoROM) != "" {
				gpu.VideoBIOS = fw.InfoROM
			}
		}
	}
}

func appendHGXFirmwareFromHWInfo(content []byte, hw *models.HardwareConfig) {
	if hw == nil || len(content) == 0 {
		return
	}

	entries := parseHGXFirmwareInventory(content)
	if len(entries) == 0 {
		return
	}

	existing := make(map[string]bool, len(hw.Firmware))
	for _, fw := range hw.Firmware {
		key := strings.ToLower(strings.TrimSpace(fw.DeviceName) + "|" + strings.TrimSpace(fw.Version))
		existing[key] = true
	}

	appendFW := func(name, version string) {
		name = strings.TrimSpace(name)
		version = strings.TrimSpace(version)
		if name == "" || version == "" {
			return
		}
		key := strings.ToLower(name + "|" + version)
		if existing[key] {
			return
		}
		existing[key] = true
		hw.Firmware = append(hw.Firmware, models.FirmwareInfo{
			DeviceName: name,
			Version:    version,
		})
	}

	for _, e := range entries {
		appendFW(e.ID, e.Version)

		if e.ActiveVersion != "" && e.InactiveVersion != "" && e.ActiveVersion != e.InactiveVersion {
			appendFW(e.ID+" Active Slot", e.ActiveVersion)
			appendFW(e.ID+" Inactive Slot", e.InactiveVersion)
		}
	}
}

func parseHGXGPUAssembly(content []byte) map[int]hgxGPUAssemblyInfo {
	result := make(map[int]hgxGPUAssemblyInfo)
	matches := reHGXGPUBlock.FindAllSubmatch(content, -1)
	for _, m := range matches {
		if len(m) != 5 {
			continue
		}

		sxmIdx, err := strconv.Atoi(string(m[1]))
		if err != nil || sxmIdx <= 0 {
			continue
		}

		result[sxmIdx] = hgxGPUAssemblyInfo{
			Model:  strings.TrimSpace(string(m[2])),
			Part:   strings.TrimSpace(string(m[3])),
			Serial: strings.TrimSpace(string(m[4])),
		}
	}
	return result
}

func parseHGXGPUFirmware(content []byte) map[int]hgxGPUFirmwareInfo {
	result := make(map[int]hgxGPUFirmwareInfo)

	matchesFW := reHGXFWBlock.FindAllSubmatch(content, -1)
	for _, m := range matchesFW {
		if len(m) != 3 {
			continue
		}
		sxmIdx, err := strconv.Atoi(string(m[1]))
		if err != nil || sxmIdx <= 0 {
			continue
		}
		version := strings.TrimSpace(string(m[2]))
		if version == "" {
			continue
		}

		current := result[sxmIdx]
		if current.Firmware == "" {
			current.Firmware = version
		}
		result[sxmIdx] = current
	}

	matchesInfoROM := reHGXInfoROM.FindAllSubmatch(content, -1)
	for _, m := range matchesInfoROM {
		if len(m) != 3 {
			continue
		}
		sxmIdx, err := strconv.Atoi(string(m[1]))
		if err != nil || sxmIdx <= 0 {
			continue
		}
		version := strings.TrimSpace(string(m[2]))
		if version == "" {
			continue
		}

		current := result[sxmIdx]
		if current.InfoROM == "" {
			current.InfoROM = version
		}
		result[sxmIdx] = current
	}

	return result
}

func parseHGXFirmwareInventory(content []byte) []hgxFirmwareInventoryEntry {
	lines := strings.Split(string(content), "\n")
	result := make([]hgxFirmwareInventoryEntry, 0)

	var current *hgxFirmwareInventoryEntry
	section := ""

	flush := func() {
		if current == nil {
			return
		}
		if current.Version == "" && current.ActiveVersion == "" && current.InactiveVersion == "" {
			current = nil
			section = ""
			return
		}
		result = append(result, *current)
		current = nil
		section = ""
	}

	for _, line := range lines {
		if m := reIDLine.FindStringSubmatch(line); len(m) > 1 {
			flush()
			id := strings.TrimSpace(m[1])
			if strings.HasPrefix(id, "HGX_") {
				current = &hgxFirmwareInventoryEntry{ID: id}
			}
			continue
		}

		if current == nil {
			continue
		}

		if strings.Contains(line, `"ActiveFirmwareSlot"`) {
			section = "active"
		}
		if strings.Contains(line, `"InactiveFirmwareSlot"`) {
			section = "inactive"
		}

		if m := reVersion.FindStringSubmatch(line); len(m) > 1 {
			version := strings.TrimSpace(m[1])
			if version == "" {
				section = ""
				continue
			}
			switch section {
			case "active":
				if current.ActiveVersion == "" {
					current.ActiveVersion = version
				}
			case "inactive":
				if current.InactiveVersion == "" {
					current.InactiveVersion = version
				}
			default:
				// Keep top-level version from the last seen plain "Version" in current entry.
				current.Version = version
			}
			section = ""
		}
	}
	flush()

	return result
}

func extractLogicalGPUIndex(slot string) (int, bool) {
	m := reSlotGPU.FindStringSubmatch(slot)
	if len(m) < 2 {
		return 0, false
	}

	idx, err := strconv.Atoi(m[1])
	if err != nil || idx < 0 {
		return 0, false
	}
	return idx, true
}

func resolveSXMIndex(logicalIdx int, bySXM map[int]hgxGPUAssemblyInfo) int {
	if sxm, ok := hgxLogicalToSXM[logicalIdx]; ok {
		if _, exists := bySXM[sxm]; exists {
			return sxm
		}
	}

	identity := logicalIdx + 1
	if _, exists := bySXM[identity]; exists {
		return identity
	}

	return identity
}

func shouldReplaceGPUModel(model string) bool {
	trimmed := strings.TrimSpace(model)
	if trimmed == "" {
		return true
	}
	switch strings.ToLower(trimmed) {
	case "vga", "3d controller", "display controller", "unknown":
		return true
	default:
		return false
	}
}

func normalizeHGXGPUInventory(hw *models.HardwareConfig, bySXM map[int]hgxGPUAssemblyInfo) {
	// Keep only logical HGX GPUs (#GPU0..#GPU7) and remove BMC VGA entries.
	filtered := make([]models.GPU, 0, len(hw.GPUs))
	present := make(map[int]bool)
	for _, gpu := range hw.GPUs {
		idx, ok := extractLogicalGPUIndex(gpu.Slot)
		if !ok || idx < 0 || idx > 7 {
			continue
		}
		present[idx] = true
		filtered = append(filtered, gpu)
	}

	// If some logical GPUs are missing in asset.json, add placeholders from HGX Redfish assembly.
	for logicalIdx := 0; logicalIdx <= 7; logicalIdx++ {
		if present[logicalIdx] {
			continue
		}
		sxm := resolveSXMIndex(logicalIdx, bySXM)
		info, ok := bySXM[sxm]
		if !ok {
			continue
		}

		filtered = append(filtered, models.GPU{
			Slot:         fmt.Sprintf("#GPU%d", logicalIdx),
			Model:        info.Model,
			Manufacturer: "NVIDIA",
			SerialNumber: info.Serial,
			PartNumber:   info.Part,
		})
	}

	hw.GPUs = filtered
}