package main

import (
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"os"
	"path/filepath"
	"strings"
)

type ProgressInfo struct {
	Percentage  float64
	CurrentFile string
	Paused      bool
}

func handleRoot(w http.ResponseWriter, r *http.Request) {
	progressMutex.Lock()
	defer progressMutex.Unlock()

	jobsInfo := make(map[string]struct {
		Percentage  float64
		CurrentFile string
		Paused      bool
	})

	for filename, info := range progress {
		jobsInfo[filename] = struct {
			Percentage  float64
			CurrentFile string
			Paused      bool
		}{
			Percentage:  info.Percentage,
			CurrentFile: info.CurrentFile,
			Paused:      info.Paused,
		}
	}

	err := templates.ExecuteTemplate(w, "index", struct {
		Jobs map[string]struct {
			Percentage  float64
			CurrentFile string
			Paused      bool
		}
	}{jobsInfo})
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}
}

func handleUpload(w http.ResponseWriter, r *http.Request) {
	err := r.ParseMultipartForm(32 << 20)
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}

	files := r.MultipartForm.File["files"]
	if len(files) == 0 {
		http.Error(w, "No files uploaded", http.StatusBadRequest)
		return
	}

	uploadedFiles := []string{}

	for _, fileHeader := range files {
		file, err := fileHeader.Open()
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		defer file.Close()

		tempFile, err := os.CreateTemp(uploadDir, fileHeader.Filename)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		defer tempFile.Close()

		_, err = io.Copy(tempFile, file)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		uploadedFiles = append(uploadedFiles, filepath.Base(tempFile.Name()))

		_, err = parseInputFile(tempFile.Name())
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
	}

	validFiles := []string{}
	for _, file := range uploadedFiles {
		if file != "" {
			validFiles = append(validFiles, file)
		}
	}

	if len(validFiles) == 0 {
		http.Error(w, "No valid files were uploaded", http.StatusBadRequest)
		return
	}

	http.Redirect(w, r, "/select?files="+url.QueryEscape(strings.Join(validFiles, ",")), http.StatusSeeOther)
}

func handleSelect(w http.ResponseWriter, r *http.Request) {
	filesParam := r.URL.Query().Get("files")
	filenames := strings.Split(filesParam, ",")

	allItems := make(map[string]map[string][]Item)

	for _, filename := range filenames {
		if filename == "" {
			continue
		}
		fullPath := filepath.Join(uploadDir, filename)

		if _, err := os.Stat(fullPath); os.IsNotExist(err) {
			continue
		}

		items, err := parseInputFile(fullPath)
		if err != nil {
			continue
		}

		sortItems(items)

		groupedItems := groupItemsBySeason(items)
		allItems[filename] = groupedItems
	}

	if len(allItems) == 0 {
		http.Error(w, "No valid files were processed", http.StatusBadRequest)
		return
	}

	err := templates.ExecuteTemplate(w, "select", struct {
		Filenames string
		AllItems  map[string]map[string][]Item
	}{
		Filenames: filesParam,
		AllItems:  allItems,
	})
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}
}

func handleProcess(w http.ResponseWriter, r *http.Request) {
	if err := r.ParseForm(); err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}

	selectedItems := r.Form["items"]
	if len(selectedItems) == 0 {
		http.Error(w, "No items selected", http.StatusBadRequest)
		return
	}

	itemsByFile := make(map[string][]string)
	for _, item := range selectedItems {
		parts := strings.SplitN(item, ":", 2)
		if len(parts) != 2 {
			continue
		}
		filename, itemName := parts[0], parts[1]
		itemsByFile[filename] = append(itemsByFile[filename], itemName)
	}

	for filename, items := range itemsByFile {
		fullPath := filepath.Join(uploadDir, filename)
		allItems, err := parseInputFile(fullPath)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		selectedItems := filterSelectedItems(allItems, items)
		sortItems(selectedItems)
		go processItems(filename, selectedItems)
	}

	http.Redirect(w, r, "/", http.StatusSeeOther)
}

func handleProgress(w http.ResponseWriter, r *http.Request) {
	filename := r.URL.Query().Get("filename")

	if r.Header.Get("Accept") == "application/json" {
		progressInfo := getProgress(filename)

		if progressInfo == nil {
			w.WriteHeader(http.StatusNotFound)
			json.NewEncoder(w).Encode(map[string]string{"error": "No progress information found"})
			return
		}

		w.Header().Set("Content-Type", "application/json")
		err := json.NewEncoder(w).Encode(progressInfo)
		if err != nil {
			http.Error(w, "Internal Server Error", http.StatusInternalServerError)
			return
		}
		return
	}

	err := templates.ExecuteTemplate(w, "progress", struct{ Filename string }{filename})
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}
}

func handlePause(w http.ResponseWriter, r *http.Request) {
	filename := r.URL.Query().Get("filename")
	if filename == "" {
		http.Error(w, "Filename is required", http.StatusBadRequest)
		return
	}

	jobsMutex.Lock()
	jobInfo, exists := jobs[filename]
	jobsMutex.Unlock()

	if !exists {
		http.Error(w, "Job not found", http.StatusNotFound)
		return
	}

	jobInfo.Paused = true
	if jobInfo.Cmd != nil && jobInfo.Cmd.Process != nil {
		jobInfo.Cmd.Process.Kill()
	}

	progressMutex.Lock()
	if progressInfo, ok := progress[filename]; ok {
		progressInfo.Paused = true
	}
	progressMutex.Unlock()

	fmt.Fprintf(w, "Pause signal sent for %s", filename)
}

func handleResume(w http.ResponseWriter, r *http.Request) {
	filename := r.URL.Query().Get("filename")
	if filename == "" {
		http.Error(w, "Filename is required", http.StatusBadRequest)
		return
	}

	jobsMutex.Lock()
	jobInfo, exists := jobs[filename]
	jobsMutex.Unlock()

	if !exists {
		http.Error(w, "Job not found", http.StatusNotFound)
		return
	}

	jobInfo.Paused = false
	jobInfo.ResumeChan <- struct{}{}

	progressMutex.Lock()
	if progressInfo, ok := progress[filename]; ok {
		progressInfo.Paused = false
	}
	progressMutex.Unlock()

	fmt.Fprintf(w, "Resume signal sent for %s", filename)
}

func handleAbort(w http.ResponseWriter, r *http.Request) {
	filename := r.URL.Query().Get("filename")
	if filename == "" {
		http.Error(w, "Filename is required", http.StatusBadRequest)
		return
	}

	jobsMutex.Lock()
	jobInfo, exists := jobs[filename]
	jobsMutex.Unlock()

	if !exists {
		http.Error(w, "Job not found", http.StatusNotFound)
		return
	}

	close(jobInfo.AbortChan)
	if jobInfo.Cmd != nil && jobInfo.Cmd.Process != nil {
		jobInfo.Cmd.Process.Kill()
	}

	if jobInfo.TempDir != "" {
		os.RemoveAll(jobInfo.TempDir)
	}

	fmt.Fprintf(w, "Abort signal sent for %s", filename)
}

func handleClearCompleted(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	clearCompletedJobs()

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(map[string]bool{"success": true})
}

func clearCompletedJobs() {
	progressMutex.Lock()
	defer progressMutex.Unlock()

	for filename, info := range progress {
		if info.Percentage >= 100 {
			delete(progress, filename)
		}
	}
}

func updateProgress(filename string, value float64, currentFile string) {
	progressMutex.Lock()
	defer progressMutex.Unlock()

	jobsMutex.Lock()
	jobInfo, exists := jobs[filename]
	jobsMutex.Unlock()

	paused := false
	if exists {
		paused = jobInfo.Paused
	}

	if existingProgress, ok := progress[filename]; ok {
		existingProgress.Percentage = value
		existingProgress.CurrentFile = currentFile
		existingProgress.Paused = paused
	} else {
		progress[filename] = &ProgressInfo{
			Percentage:  value,
			CurrentFile: currentFile,
			Paused:      paused,
		}
	}
}