package server

import (
	"context"
	"crypto/rand"
	"encoding/json"
	"fmt"
	"html/template"
	"net/http"
	"os"
	"regexp"
	"sort"
	"strings"
	"time"

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

func (s *Server) handleIndex(w http.ResponseWriter, r *http.Request) {
	if r.URL.Path != "/" {
		http.NotFound(w, r)
		return
	}

	tmplContent, err := WebFS.ReadFile("templates/index.html")
	if err != nil {
		http.Error(w, "Template not found", http.StatusInternalServerError)
		return
	}

	tmpl, err := template.New("index").Parse(string(tmplContent))
	if err != nil {
		http.Error(w, "Template parse error", http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	tmpl.Execute(w, nil)
}

func (s *Server) handleUpload(w http.ResponseWriter, r *http.Request) {
	// Max 100MB file
	if err := r.ParseMultipartForm(100 << 20); err != nil {
		jsonError(w, "File too large", http.StatusBadRequest)
		return
	}

	file, header, err := r.FormFile("archive")
	if err != nil {
		jsonError(w, "Failed to read file", http.StatusBadRequest)
		return
	}
	defer file.Close()

	// Parse archive
	p := parser.NewBMCParser()
	if err := p.ParseFromReader(file, header.Filename); err != nil {
		jsonError(w, "Failed to parse archive: "+err.Error(), http.StatusBadRequest)
		return
	}

	result := p.Result()
	applyArchiveSourceMetadata(result)
	s.SetResult(result)
	s.SetDetectedVendor(p.DetectedVendor())

	jsonResponse(w, map[string]interface{}{
		"status":   "ok",
		"message":  "File uploaded and parsed successfully",
		"filename": header.Filename,
		"vendor":   p.DetectedVendor(),
		"stats": map[string]int{
			"events":  len(result.Events),
			"sensors": len(result.Sensors),
			"fru":     len(result.FRU),
		},
	})
}

func (s *Server) handleGetParsers(w http.ResponseWriter, r *http.Request) {
	jsonResponse(w, map[string]interface{}{
		"parsers": parser.ListParsersInfo(),
	})
}

func (s *Server) handleGetEvents(w http.ResponseWriter, r *http.Request) {
	result := s.GetResult()
	if result == nil {
		jsonResponse(w, []interface{}{})
		return
	}

	// Sort events by timestamp (newest first)
	events := make([]models.Event, len(result.Events))
	copy(events, result.Events)

	// Sort in descending order using sort.Slice (newest first)
	sort.Slice(events, func(i, j int) bool {
		return events[i].Timestamp.After(events[j].Timestamp)
	})

	jsonResponse(w, events)
}

func (s *Server) handleGetSensors(w http.ResponseWriter, r *http.Request) {
	result := s.GetResult()
	if result == nil {
		jsonResponse(w, []interface{}{})
		return
	}
	jsonResponse(w, result.Sensors)
}

func (s *Server) handleGetConfig(w http.ResponseWriter, r *http.Request) {
	result := s.GetResult()
	if result == nil {
		jsonResponse(w, map[string]interface{}{})
		return
	}

	response := map[string]interface{}{
		"source_type":  result.SourceType,
		"protocol":     result.Protocol,
		"target_host":  result.TargetHost,
		"collected_at": result.CollectedAt,
	}

	if result.Hardware == nil {
		response["hardware"] = map[string]interface{}{}
		response["specification"] = []SpecLine{}
		jsonResponse(w, response)
		return
	}

	// Build specification summary
	spec := buildSpecification(result)

	response["hardware"] = result.Hardware
	response["specification"] = spec
	jsonResponse(w, response)
}

// SpecLine represents a single line in specification
type SpecLine struct {
	Category string `json:"category"`
	Name     string `json:"name"`
	Quantity int    `json:"quantity"`
}

func buildSpecification(result *models.AnalysisResult) []SpecLine {
	var spec []SpecLine
	hw := result.Hardware
	if hw == nil {
		return spec
	}

	// CPUs - group by model
	cpuGroups := make(map[string]int)
	cpuDetails := make(map[string]models.CPU)
	for _, cpu := range hw.CPUs {
		cpuGroups[cpu.Model]++
		cpuDetails[cpu.Model] = cpu
	}
	for model, count := range cpuGroups {
		cpu := cpuDetails[model]
		name := fmt.Sprintf("Intel %s (%.1fGHz %dC %dW)",
			model,
			float64(cpu.FrequencyMHz)/1000,
			cpu.Cores,
			cpu.TDP)
		spec = append(spec, SpecLine{Category: "Процессор", Name: name, Quantity: count})
	}

	// Memory - group by size, type and frequency (only installed modules)
	memGroups := make(map[string]int)
	for _, mem := range hw.Memory {
		// Skip empty slots (not present or 0 size)
		if !mem.Present || mem.SizeMB == 0 {
			continue
		}
		// Include frequency if available
		key := ""
		if mem.CurrentSpeedMHz > 0 {
			key = fmt.Sprintf("%s %dGB %dMHz", mem.Type, mem.SizeMB/1024, mem.CurrentSpeedMHz)
		} else {
			key = fmt.Sprintf("%s %dGB", mem.Type, mem.SizeMB/1024)
		}
		memGroups[key]++
	}
	for key, count := range memGroups {
		spec = append(spec, SpecLine{Category: "Память", Name: key, Quantity: count})
	}

	// Storage - group by type and capacity
	storGroups := make(map[string]int)
	for _, stor := range hw.Storage {
		var key string
		if stor.SizeGB >= 1000 {
			key = fmt.Sprintf("%s %s %.2fTB", stor.Type, stor.Interface, float64(stor.SizeGB)/1000)
		} else {
			key = fmt.Sprintf("%s %s %dGB", stor.Type, stor.Interface, stor.SizeGB)
		}
		storGroups[key]++
	}
	for key, count := range storGroups {
		spec = append(spec, SpecLine{Category: "Накопитель", Name: key, Quantity: count})
	}

	// PCIe devices - group by device class/name and manufacturer
	pcieGroups := make(map[string]int)
	pcieDetails := make(map[string]models.PCIeDevice)
	for _, pcie := range hw.PCIeDevices {
		// Create unique key from manufacturer + device class/name
		key := pcie.DeviceClass
		if pcie.Manufacturer != "" {
			key = pcie.Manufacturer + " " + pcie.DeviceClass
		}
		if pcie.PartNumber != "" && pcie.PartNumber != pcie.DeviceClass {
			key = key + " (" + pcie.PartNumber + ")"
		}
		pcieGroups[key]++
		pcieDetails[key] = pcie
	}
	for key, count := range pcieGroups {
		pcie := pcieDetails[key]
		category := "PCIe устройство"
		name := key

		// Determine category based on device class or known GPU names
		deviceClass := pcie.DeviceClass
		isGPU := isGPUDevice(deviceClass)
		isNetwork := deviceClass == "Network" || strings.Contains(deviceClass, "ConnectX")

		if isGPU {
			category = "Графический процессор"
		} else if isNetwork {
			category = "Сетевой адаптер"
		} else if deviceClass == "NVMe" || deviceClass == "RAID" || deviceClass == "SAS" || deviceClass == "SATA" || deviceClass == "Storage" {
			category = "Контроллер"
		}

		spec = append(spec, SpecLine{Category: category, Name: name, Quantity: count})
	}

	// Power supplies - group by model/wattage
	psuGroups := make(map[string]int)
	for _, psu := range hw.PowerSupply {
		key := psu.Model
		if key == "" && psu.WattageW > 0 {
			key = fmt.Sprintf("%dW", psu.WattageW)
		}
		if key != "" {
			psuGroups[key]++
		}
	}
	for key, count := range psuGroups {
		spec = append(spec, SpecLine{Category: "Блок питания", Name: key, Quantity: count})
	}

	return spec
}

func (s *Server) handleGetSerials(w http.ResponseWriter, r *http.Request) {
	result := s.GetResult()
	if result == nil {
		jsonResponse(w, []interface{}{})
		return
	}

	// Collect all serial numbers from various sources
	type SerialEntry struct {
		Component    string `json:"component"`
		Location     string `json:"location,omitempty"`
		SerialNumber string `json:"serial_number"`
		Manufacturer string `json:"manufacturer,omitempty"`
		PartNumber   string `json:"part_number,omitempty"`
		Category     string `json:"category"`
	}

	var serials []SerialEntry

	// From FRU
	for _, fru := range result.FRU {
		if fru.SerialNumber == "" {
			continue
		}
		name := fru.ProductName
		if name == "" {
			name = fru.Description
		}
		serials = append(serials, SerialEntry{
			Component:    name,
			SerialNumber: fru.SerialNumber,
			Manufacturer: fru.Manufacturer,
			PartNumber:   fru.PartNumber,
			Category:     "FRU",
		})
	}

	// From Hardware
	if result.Hardware != nil {
		// Board
		if result.Hardware.BoardInfo.SerialNumber != "" {
			serials = append(serials, SerialEntry{
				Component:    result.Hardware.BoardInfo.ProductName,
				SerialNumber: result.Hardware.BoardInfo.SerialNumber,
				Manufacturer: result.Hardware.BoardInfo.Manufacturer,
				PartNumber:   result.Hardware.BoardInfo.PartNumber,
				Category:     "Board",
			})
		}

		// CPUs
		for _, cpu := range result.Hardware.CPUs {
			sn := cpu.SerialNumber
			if sn == "" {
				sn = cpu.PPIN // Use PPIN as fallback identifier
			}
			if sn == "" {
				continue
			}
			serials = append(serials, SerialEntry{
				Component:    cpu.Model,
				Location:     fmt.Sprintf("CPU%d", cpu.Socket),
				SerialNumber: sn,
				Category:     "CPU",
			})
		}

		// Memory DIMMs
		for _, mem := range result.Hardware.Memory {
			if mem.SerialNumber == "" {
				continue
			}
			location := mem.Location
			if location == "" {
				location = mem.Slot
			}
			serials = append(serials, SerialEntry{
				Component:    mem.PartNumber,
				Location:     location,
				SerialNumber: mem.SerialNumber,
				Manufacturer: mem.Manufacturer,
				PartNumber:   mem.PartNumber,
				Category:     "Memory",
			})
		}

		// Storage
		for _, stor := range result.Hardware.Storage {
			if stor.SerialNumber == "" {
				continue
			}
			serials = append(serials, SerialEntry{
				Component:    stor.Model,
				Location:     stor.Slot,
				SerialNumber: stor.SerialNumber,
				Manufacturer: stor.Manufacturer,
				Category:     "Storage",
			})
		}

		// PCIe devices
		for _, pcie := range result.Hardware.PCIeDevices {
			if pcie.SerialNumber == "" {
				continue
			}
			serials = append(serials, SerialEntry{
				Component:    pcie.DeviceClass,
				Location:     pcie.Slot,
				SerialNumber: pcie.SerialNumber,
				Manufacturer: pcie.Manufacturer,
				PartNumber:   pcie.PartNumber,
				Category:     "PCIe",
			})
		}

		// Network cards
		for _, nic := range result.Hardware.NetworkCards {
			if nic.SerialNumber == "" {
				continue
			}
			serials = append(serials, SerialEntry{
				Component:    nic.Model,
				SerialNumber: nic.SerialNumber,
				Category:     "Network",
			})
		}

		// Power supplies
		for _, psu := range result.Hardware.PowerSupply {
			if psu.SerialNumber == "" {
				continue
			}
			serials = append(serials, SerialEntry{
				Component:    psu.Model,
				Location:     psu.Slot,
				SerialNumber: psu.SerialNumber,
				Manufacturer: psu.Vendor,
				Category:     "PSU",
			})
		}

		// Firmware (using version as "serial number" for display)
		for _, fw := range result.Hardware.Firmware {
			serials = append(serials, SerialEntry{
				Component:    fw.DeviceName,
				SerialNumber: fw.Version,
				Category:     "Firmware",
			})
		}
	}

	jsonResponse(w, serials)
}

func (s *Server) handleGetFirmware(w http.ResponseWriter, r *http.Request) {
	result := s.GetResult()
	if result == nil || result.Hardware == nil {
		jsonResponse(w, []interface{}{})
		return
	}

	// Deduplicate firmware by extracting model name and version
	// E.g., "PSU0 (AP-CR3000F12BY)" and "PSU1 (AP-CR3000F12BY)" with same version -> one entry
	type FirmwareEntry struct {
		Component string `json:"component"`
		Model     string `json:"model"`
		Version   string `json:"version"`
	}

	seen := make(map[string]bool)
	var deduplicated []FirmwareEntry

	for _, fw := range result.Hardware.Firmware {
		// Extract component type and model from device name
		component, model := extractFirmwareComponentAndModel(fw.DeviceName)
		key := component + "|" + model + "|" + fw.Version

		if !seen[key] {
			seen[key] = true
			deduplicated = append(deduplicated, FirmwareEntry{
				Component: component,
				Model:     model,
				Version:   fw.Version,
			})
		}
	}

	jsonResponse(w, deduplicated)
}

// extractFirmwareComponentAndModel extracts the component type and model from firmware device name
func extractFirmwareComponentAndModel(deviceName string) (component, model string) {
	// Parse different firmware name formats and extract component + model

	// For "PSU0 (AP-CR3000F12BY)" -> component: "PSU", model: "AP-CR3000F12BY"
	if strings.HasPrefix(deviceName, "PSU") {
		if idx := strings.Index(deviceName, "("); idx != -1 {
			model = strings.Trim(deviceName[idx:], "()")
			return "PSU", model
		}
		return "PSU", "-"
	}

	// For "CPU0 Microcode" -> component: "CPU Microcode", model: "-"
	if strings.HasPrefix(deviceName, "CPU") && strings.Contains(deviceName, "Microcode") {
		return "CPU Microcode", "-"
	}

	// For "NIC #CPU1_PCIE9 (MCX512A-ACAT)" -> component: "NIC", model: "MCX512A-ACAT"
	if strings.HasPrefix(deviceName, "NIC ") {
		if idx := strings.Index(deviceName, "("); idx != -1 {
			model = strings.Trim(deviceName[idx:], "()")
			return "NIC", model
		}
		return "NIC", "-"
	}

	// For "HDD Samsung MZ7L33T8HBNA-00A07" -> component: "HDD", model: "Samsung MZ7L33T8HBNA-00A07"
	if strings.HasPrefix(deviceName, "HDD ") {
		return "HDD", strings.TrimPrefix(deviceName, "HDD ")
	}

	// For "SSD Samsung MZ7..." -> component: "SSD", model: "Samsung MZ7..."
	if strings.HasPrefix(deviceName, "SSD ") {
		return "SSD", strings.TrimPrefix(deviceName, "SSD ")
	}

	// For "NVMe KIOXIA..." -> component: "NVMe", model: "KIOXIA..."
	if strings.HasPrefix(deviceName, "NVMe ") {
		return "NVMe", strings.TrimPrefix(deviceName, "NVMe ")
	}

	// For simple names like "BIOS", "ME", "BKC", "Virtual MicroCo"
	// component = name, model = "-"
	return deviceName, "-"
}

func (s *Server) handleGetStatus(w http.ResponseWriter, r *http.Request) {
	result := s.GetResult()
	if result == nil {
		jsonResponse(w, map[string]interface{}{
			"loaded": false,
		})
		return
	}

	jsonResponse(w, map[string]interface{}{
		"loaded":       true,
		"filename":     result.Filename,
		"vendor":       s.GetDetectedVendor(),
		"source_type":  result.SourceType,
		"protocol":     result.Protocol,
		"target_host":  result.TargetHost,
		"collected_at": result.CollectedAt,
		"stats": map[string]int{
			"events":  len(result.Events),
			"sensors": len(result.Sensors),
			"fru":     len(result.FRU),
		},
	})
}

func (s *Server) handleExportCSV(w http.ResponseWriter, r *http.Request) {
	result := s.GetResult()

	w.Header().Set("Content-Type", "text/csv; charset=utf-8")
	w.Header().Set("Content-Disposition", "attachment; filename=serials.csv")

	exp := exporter.New(result)
	exp.ExportCSV(w)
}

func (s *Server) handleExportJSON(w http.ResponseWriter, r *http.Request) {
	result := s.GetResult()

	w.Header().Set("Content-Type", "application/json")
	w.Header().Set("Content-Disposition", "attachment; filename=report.json")

	exp := exporter.New(result)
	exp.ExportJSON(w)
}

func (s *Server) handleExportTXT(w http.ResponseWriter, r *http.Request) {
	result := s.GetResult()

	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
	w.Header().Set("Content-Disposition", "attachment; filename=report.txt")

	exp := exporter.New(result)
	exp.ExportTXT(w)
}

func (s *Server) handleClear(w http.ResponseWriter, r *http.Request) {
	s.SetResult(nil)
	s.SetDetectedVendor("")
	jsonResponse(w, map[string]string{
		"status":  "ok",
		"message": "Data cleared",
	})
}

func (s *Server) handleShutdown(w http.ResponseWriter, r *http.Request) {
	jsonResponse(w, map[string]string{
		"status":  "ok",
		"message": "Server shutting down",
	})

	// Shutdown in a goroutine so the response can be sent
	go func() {
		time.Sleep(100 * time.Millisecond)
		s.Shutdown()
		os.Exit(0)
	}()
}

func (s *Server) handleCollectStart(w http.ResponseWriter, r *http.Request) {
	var req CollectRequest
	decoder := json.NewDecoder(r.Body)
	decoder.DisallowUnknownFields()
	if err := decoder.Decode(&req); err != nil {
		jsonError(w, "Invalid JSON body", http.StatusBadRequest)
		return
	}

	if err := validateCollectRequest(req); err != nil {
		jsonError(w, err.Error(), http.StatusUnprocessableEntity)
		return
	}

	job := s.jobManager.CreateJob(req)
	s.SetResult(newAPIResult(req))
	s.SetDetectedVendor("")
	s.startMockCollectionJob(job.ID, req)

	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusAccepted)
	_ = json.NewEncoder(w).Encode(job.toJobResponse("Collection job accepted"))
}

func (s *Server) handleCollectStatus(w http.ResponseWriter, r *http.Request) {
	jobID := strings.TrimSpace(r.PathValue("id"))
	if !isValidCollectJobID(jobID) {
		jsonError(w, "Invalid collect job id", http.StatusBadRequest)
		return
	}

	job, ok := s.jobManager.GetJob(jobID)
	if !ok {
		jsonError(w, "Collect job not found", http.StatusNotFound)
		return
	}

	jsonResponse(w, job.toStatusResponse())
}

func (s *Server) handleCollectCancel(w http.ResponseWriter, r *http.Request) {
	jobID := strings.TrimSpace(r.PathValue("id"))
	if !isValidCollectJobID(jobID) {
		jsonError(w, "Invalid collect job id", http.StatusBadRequest)
		return
	}

	job, ok := s.jobManager.CancelJob(jobID)
	if !ok {
		jsonError(w, "Collect job not found", http.StatusNotFound)
		return
	}

	jsonResponse(w, job.toStatusResponse())
}

func (s *Server) startMockCollectionJob(jobID string, req CollectRequest) {
	ctx, cancel := context.WithCancel(context.Background())
	if attached := s.jobManager.AttachJobCancel(jobID, cancel); !attached {
		cancel()
		return
	}

	go func() {
		steps := []struct {
			delay    time.Duration
			status   string
			progress int
			log      string
		}{
			{delay: 250 * time.Millisecond, status: CollectStatusRunning, progress: 20, log: "Подключение..."},
			{delay: 250 * time.Millisecond, status: CollectStatusRunning, progress: 50, log: "Сбор инвентаря..."},
			{delay: 250 * time.Millisecond, status: CollectStatusRunning, progress: 80, log: "Нормализация..."},
		}

		for _, step := range steps {
			if !waitWithCancel(ctx, step.delay) {
				return
			}

			if job, ok := s.jobManager.GetJob(jobID); !ok || isTerminalCollectStatus(job.Status) {
				return
			}

			s.jobManager.UpdateJobStatus(jobID, step.status, step.progress, "")
			s.jobManager.AppendJobLog(jobID, step.log)
		}

		if !waitWithCancel(ctx, 250*time.Millisecond) {
			return
		}

		if job, ok := s.jobManager.GetJob(jobID); !ok || isTerminalCollectStatus(job.Status) {
			return
		}

		if strings.Contains(strings.ToLower(req.Host), "fail") {
			s.jobManager.UpdateJobStatus(jobID, CollectStatusFailed, 100, "Mock: не удалось завершить сбор")
			s.jobManager.AppendJobLog(jobID, "Сбор завершен с ошибкой")
			return
		}

		s.jobManager.UpdateJobStatus(jobID, CollectStatusSuccess, 100, "")
		s.jobManager.AppendJobLog(jobID, "Сбор завершен")
	}()
}

func waitWithCancel(ctx context.Context, d time.Duration) bool {
	timer := time.NewTimer(d)
	defer timer.Stop()

	select {
	case <-ctx.Done():
		return false
	case <-timer.C:
		return true
	}
}

func validateCollectRequest(req CollectRequest) error {
	if strings.TrimSpace(req.Host) == "" {
		return fmt.Errorf("field 'host' is required")
	}
	switch req.Protocol {
	case "redfish", "ipmi":
	default:
		return fmt.Errorf("field 'protocol' must be one of: redfish, ipmi")
	}
	if req.Port < 1 || req.Port > 65535 {
		return fmt.Errorf("field 'port' must be in range 1..65535")
	}
	if strings.TrimSpace(req.Username) == "" {
		return fmt.Errorf("field 'username' is required")
	}
	switch req.AuthType {
	case "password":
		if strings.TrimSpace(req.Password) == "" {
			return fmt.Errorf("field 'password' is required when auth_type=password")
		}
	case "token":
		if strings.TrimSpace(req.Token) == "" {
			return fmt.Errorf("field 'token' is required when auth_type=token")
		}
	default:
		return fmt.Errorf("field 'auth_type' must be one of: password, token")
	}
	switch req.TLSMode {
	case "strict", "insecure":
	default:
		return fmt.Errorf("field 'tls_mode' must be one of: strict, insecure")
	}

	return nil
}

var collectJobIDPattern = regexp.MustCompile(`^job_[a-zA-Z0-9_-]{8,}$`)

func isValidCollectJobID(id string) bool {
	return collectJobIDPattern.MatchString(id)
}

func generateJobID() string {
	buf := make([]byte, 8)
	if _, err := rand.Read(buf); err != nil {
		return fmt.Sprintf("job_%d", time.Now().UnixNano())
	}
	return fmt.Sprintf("job_%x", buf)
}

func applyArchiveSourceMetadata(result *models.AnalysisResult) {
	if result == nil {
		return
	}
	result.SourceType = models.SourceTypeArchive
	result.Protocol = ""
	result.TargetHost = ""
	result.CollectedAt = time.Now().UTC()
}

func newAPIResult(req CollectRequest) *models.AnalysisResult {
	return &models.AnalysisResult{
		SourceType:  models.SourceTypeAPI,
		Protocol:    req.Protocol,
		TargetHost:  req.Host,
		CollectedAt: time.Now().UTC(),
		Events:      make([]models.Event, 0),
		FRU:         make([]models.FRUInfo, 0),
		Sensors:     make([]models.SensorReading, 0),
	}
}

func jsonResponse(w http.ResponseWriter, data interface{}) {
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(data)
}

func jsonError(w http.ResponseWriter, message string, code int) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(code)
	json.NewEncoder(w).Encode(map[string]string{"error": message})
}

// isGPUDevice checks if device class indicates a GPU
func isGPUDevice(deviceClass string) bool {
	// Standard PCI class names
	if deviceClass == "VGA" || deviceClass == "3D Controller" || deviceClass == "Display" {
		return true
	}
	// Known GPU model patterns
	gpuPatterns := []string{
		"L40", "A100", "A10", "A16", "A30", "H100", "H200", "V100",
		"RTX", "GTX", "Quadro", "Tesla",
		"Instinct", "Radeon",
		"AST2500", "AST2600", // ASPEED BMC VGA
	}
	upperClass := strings.ToUpper(deviceClass)
	for _, pattern := range gpuPatterns {
		if strings.Contains(upperClass, strings.ToUpper(pattern)) {
			return true
		}
	}
	return false
}