package main

import (
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"time"

	"inou/lib"
)

// Upload represents a file upload entry for display
type Upload struct {
	ID                                                              string
	FileName, FilePath, SizeHuman, UploadedAt, ExpiresAt, DeletedReason string
	Category, Status                                                string
	Deleted                                                         bool
}

// UploadData is the JSON structure stored in Entry.Data for uploads
type UploadData struct {
	Path       string `json:"path"`
	RelPath    string `json:"rel_path,omitempty"` // Original relative path for folder uploads
	Size       int64  `json:"size"`
	UploadedBy string `json:"uploaded_by"`
	Status     string `json:"status"`
}

func formatBytes(b int64) string {
	const unit = 1024
	if b < unit {
		return fmt.Sprintf("%d B", b)
	}
	div, exp := int64(unit), 0
	for n := b / unit; n >= unit; n /= unit {
		div *= unit
		exp++
	}
	return fmt.Sprintf("%.1f %cB", float64(b)/float64(div), "KMGTPE"[exp])
}

// getUploads returns all uploads for a dossier using lib.EntryList
func getUploads(dossierID string) []Upload {
	var uploads []Upload

	entries, err := lib.EntryList(lib.SystemAccessorID, "", lib.CategoryUpload, &lib.EntryFilter{ // nil ctx - internal operation
		DossierID: dossierID,
		Limit:     50,
	})
	if err != nil {
		return uploads
	}

	for _, e := range entries {
		var data UploadData
		json.Unmarshal([]byte(e.Data), &data)

		u := Upload{
			ID:         e.EntryID,
			FileName:   e.Value,
			FilePath:   data.Path,
			Category:   e.Type,
			Status:     data.Status,
			SizeHuman:  formatBytes(data.Size),
			UploadedAt: time.Unix(e.Timestamp, 0).Format("Jan 2"),
			ExpiresAt:  time.Unix(e.TimestampEnd, 0).Format("Jan 2"),
		}
		if e.Status != 0 {
			u.Deleted = true
			u.DeletedReason = "Deleted"
		}
		uploads = append(uploads, u)
	}
	return uploads
}

// getUploadEntry retrieves a single upload entry using lib.EntryGet
func getUploadEntry(entryID, dossierID string) (filePath, fileName, category, status string, deleted bool) {
	e, err := lib.EntryGet(nil, entryID) // nil ctx - internal operation
	if err != nil || e == nil {
		return
	}

	// Verify it belongs to the right dossier and is an upload
	if e.DossierID != dossierID || e.Category != lib.CategoryUpload {
		return
	}

	var data UploadData
	json.Unmarshal([]byte(e.Data), &data)

	fileName = e.Value
	category = e.Type
	filePath = data.Path
	status = data.Status
	deleted = e.Status != 0
	return
}

// findUploadByFilename finds existing uploads with the same filename
func findUploadByFilename(dossierID, filename string) []*lib.Entry {
	entries, err := lib.EntryList(lib.SystemAccessorID, "", lib.CategoryUpload, &lib.EntryFilter{ // nil ctx - internal operation
		DossierID: dossierID,
		Value:     filename,
	})
	if err != nil {
		return nil
	}
	return entries
}

func handleUploadPage(w http.ResponseWriter, r *http.Request) {
	p := getLoggedInDossier(r)
	if p == nil {
		http.Redirect(w, r, "/", http.StatusSeeOther)
		return
	}
	parts := strings.Split(r.URL.Path, "/")
	if len(parts) < 4 {
		http.NotFound(w, r)
		return
	}
	targetID := parts[2]

	isSelf := targetID == p.DossierID
	if !isSelf {
		if access, found := getAccess(formatHexID(p.DossierID), formatHexID(targetID)); !found || !access.CanEdit {
			http.Error(w, "Forbidden", http.StatusForbidden)
			return
		}
	}

	target, _ := lib.DossierGet(nil, targetID) // nil ctx - internal operation
	if target == nil {
		http.NotFound(w, r)
		return
	}
	lang := getLang(r)
	data := PageData{
		Page: "upload", Lang: lang, T: translations[lang],
		Dossier: p, TargetDossier: target,
		UploadList: getUploads(targetID),
	}
	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	templates.ExecuteTemplate(w, "base.tmpl", data)
}

func handleUploadPost(w http.ResponseWriter, r *http.Request) {
	p := getLoggedInDossier(r)
	if p == nil {
		http.Error(w, "Unauthorized", http.StatusUnauthorized)
		return
	}
	parts := strings.Split(r.URL.Path, "/")
	if len(parts) < 4 {
		http.NotFound(w, r)
		return
	}
	targetID := parts[2]

	isSelf := targetID == p.DossierID
	if !isSelf {
		if access, found := getAccess(formatHexID(p.DossierID), formatHexID(targetID)); !found || !access.CanEdit {
			http.Error(w, "Forbidden", http.StatusForbidden)
			return
		}
	}

	r.ParseMultipartForm(10 << 30)
	file, header, err := r.FormFile("file")
	if err != nil {
		http.Error(w, "No file", http.StatusBadRequest)
		return
	}
	defer file.Close()

	relPath := r.FormValue("path")
	if relPath == "" {
		relPath = header.Filename
	}
	fileName := filepath.Base(relPath)
	category := r.FormValue("category")

	// Read file content
	content, err := io.ReadAll(file)
	if err != nil {
		http.Error(w, "Failed to read", http.StatusInternalServerError)
		return
	}

	// Generate file ID using lib.NewID() (Hex16 format)
	fileID := lib.NewID()

	// Store in uploads directory
	uploadDir := filepath.Join(uploadsDir, formatHexID(targetID))
	filePath := filepath.Join(uploadDir, fileID)
	os.MkdirAll(uploadDir, 0755)
	if err := lib.EncryptFile(content, filePath); err != nil {
		w.Header().Set("Content-Type", "application/json")
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte(`{"status":"error","message":"Upload failed, we've been notified"}`))
		return
	}
	written := int64(len(content))

	// Delete existing upload with same filename (re-upload cleanup)
	existingUploads := findUploadByFilename(targetID, fileName)
	for _, old := range existingUploads {
		lib.EntryDeleteTree(nil, targetID, old.EntryID) // nil ctx = internal upload cleanup
	}

	now := time.Now().Unix()
	expires := now + 7*24*60*60

	uploadData := UploadData{
		Path:       filePath,
		RelPath:    relPath,
		Size:       written,
		UploadedBy: p.DossierID,
		Status:     "uploaded",
	}
	dataJSON, _ := json.Marshal(uploadData)

	uploadEntry := &lib.Entry{
		DossierID:    targetID,
		Category:     lib.CategoryUpload,
		Type:         category,
		Value:        fileName,
		Timestamp:    now,
		TimestampEnd: expires,
		Data:         string(dataJSON),
	}
	lib.EntryWrite(nil, uploadEntry) // nil ctx - internal operation
	entryID := uploadEntry.EntryID
	lib.AuditLog(p.DossierID, "file_upload", targetID, fileName)

	// Notify via Signal
	if target, _ := lib.DossierGet(nil, targetID); target != nil { // nil ctx - internal operation
		sizeStr := fmt.Sprintf("%d B", written)
		if written >= 1024*1024 {
			sizeStr = fmt.Sprintf("%.1f MB", float64(written)/(1024*1024))
		} else if written >= 1024 {
			sizeStr = fmt.Sprintf("%.1f KB", float64(written)/1024)
		}
		lib.SendSignal(fmt.Sprintf("Upload: %s → %s (%s, %s, %s)", p.Name, target.Name, category, fileName, sizeStr))
	}

	// Spawn genome processing for genetics uploads
	if category == "genetics" {
		go processGenomeUpload(entryID, targetID, filePath)
	}
	w.Header().Set("Content-Type", "application/json")
	w.Write([]byte(fmt.Sprintf(`{"status":"ok","id":"%s"}`, entryID)))
}

func handleDeleteFile(w http.ResponseWriter, r *http.Request) {
	if r.Method != "POST" {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}
	p := getLoggedInDossier(r)
	if p == nil {
		http.Error(w, "Unauthorized", http.StatusUnauthorized)
		return
	}

	// Parse /dossier/{hex}/files/{id}/delete
	parts := strings.Split(r.URL.Path, "/")
	if len(parts) < 6 {
		http.NotFound(w, r)
		return
	}
	targetID := parts[2]
	fileID := parts[4]

	isSelf := targetID == p.DossierID
	if !isSelf {
		if access, found := getAccess(formatHexID(p.DossierID), formatHexID(targetID)); !found || !access.CanEdit {
			http.Error(w, "Forbidden", http.StatusForbidden)
			return
		}
	}

	// Get file info for audit and deletion
	filePath, fileName, _, _, _ := getUploadEntry(fileID, targetID)
	if filePath != "" {
		os.Remove(filePath)
	}

	// Mark as deleted using lib.EntryGet + lib.EntryWrite
	entry, err := lib.EntryGet(nil, fileID) // nil ctx - internal operation
	if err == nil && entry != nil && entry.DossierID == targetID {
		entry.Status = 1 // Mark as deleted
		lib.EntryWrite(nil, entry) // nil ctx - internal operation
	}

	lib.AuditLog(p.DossierID, "file_delete", targetID, fileName)
	http.Redirect(w, r, fmt.Sprintf("/dossier/%s/upload", formatHexID(targetID)), http.StatusSeeOther)
}

func handleUpdateFile(w http.ResponseWriter, r *http.Request) {
	if r.Method != "POST" {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}
	p := getLoggedInDossier(r)
	if p == nil {
		http.Error(w, "Unauthorized", http.StatusUnauthorized)
		return
	}

	// Parse /dossier/{hex}/files/{id}/update
	parts := strings.Split(r.URL.Path, "/")
	if len(parts) < 6 {
		http.NotFound(w, r)
		return
	}
	targetID := parts[2]
	fileID := parts[4]

	isSelf := targetID == p.DossierID
	if !isSelf {
		if access, found := getAccess(formatHexID(p.DossierID), formatHexID(targetID)); !found || !access.CanEdit {
			http.Error(w, "Forbidden", http.StatusForbidden)
			return
		}
	}

	// Get entry using lib.EntryGet
	entry, err := lib.EntryGet(nil, fileID) // nil ctx - internal operation
	if err != nil || entry == nil || entry.DossierID != targetID || entry.Category != lib.CategoryUpload {
		http.NotFound(w, r)
		return
	}

	if entry.Status != 0 {
		http.NotFound(w, r) // Deleted
		return
	}

	var data UploadData
	json.Unmarshal([]byte(entry.Data), &data)

	if data.Status != "uploaded" {
		http.Error(w, "Cannot modify processed file", http.StatusBadRequest)
		return
	}

	newCategory := r.FormValue("category")
	if newCategory != "" && newCategory != entry.Type {
		entry.Type = newCategory
		lib.EntryWrite(nil, entry) // nil ctx - internal operation
		lib.AuditLog(p.DossierID, "file_category_change", targetID, entry.Value)
	}

	http.Redirect(w, r, fmt.Sprintf("/dossier/%s/upload", formatHexID(targetID)), http.StatusSeeOther)
}

func handleProcessImaging(w http.ResponseWriter, r *http.Request) {
	logFile := "/tmp/process-imaging.log"
	log := func(msg string) { f, _ := os.OpenFile(logFile, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644); f.WriteString(msg + "\n"); f.Close() }
	log(fmt.Sprintf("Request: %s %s", r.Method, r.URL.Path))
	if r.Method != "POST" {
		log("Rejected: not POST")
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}
	log("Method OK")
	p := getLoggedInDossier(r)
	if p == nil {
		log("Rejected: not logged in")
		http.Error(w, "Unauthorized", http.StatusUnauthorized)
		return
	}
	log(fmt.Sprintf("Logged in as: %s", p.DossierID))

	// Parse /dossier/{hex}/process-imaging
	parts := strings.Split(r.URL.Path, "/")
	if len(parts) < 4 {
		http.NotFound(w, r)
		return
	}
	targetID := parts[2]

	isSelf := targetID == p.DossierID
	log(fmt.Sprintf("Target: %s, isSelf: %v", targetID, isSelf))
	if !isSelf {
		if access, found := getAccess(formatHexID(p.DossierID), formatHexID(targetID)); !found || !access.CanEdit {
			log("Rejected: no access")
			http.Error(w, "Forbidden", http.StatusForbidden)
			return
		}
	}
	log("Access OK")

	// Get all uploads with status=uploaded (any type for now)
	entries, err := lib.EntryList(lib.SystemAccessorID, "", lib.CategoryUpload, &lib.EntryFilter{
		DossierID: targetID,
	})
	if err != nil {
		log(fmt.Sprintf("EntryList error: %v", err))
		http.Error(w, "Failed to list uploads", http.StatusInternalServerError)
		return
	}
	log(fmt.Sprintf("Found %d entries", len(entries)))

	// Filter to only "uploaded" status
	var pending []*lib.Entry
	for _, e := range entries {
		if e.Status != 0 {
			continue // deleted
		}
		var data UploadData
		json.Unmarshal([]byte(e.Data), &data)
		if data.Status == "uploaded" {
			pending = append(pending, e)
		}
	}
	log(fmt.Sprintf("Pending uploads: %d", len(pending)))

	if len(pending) == 0 {
		log("No pending - sending done")
		w.Header().Set("Content-Type", "text/event-stream")
		fmt.Fprintf(w, "data: {\"type\":\"done\",\"message\":\"No pending imaging uploads\"}\n\n")
		return
	}
	// Create temp directory for decrypted files
	tempDir, err := os.MkdirTemp("", "dicom-import-*")
	if err != nil {
		log("Failed to create temp dir")
		http.Error(w, "Failed to create temp dir", http.StatusInternalServerError)
		return
	}
	defer os.RemoveAll(tempDir)
	log(fmt.Sprintf("Temp dir: %s", tempDir))

	// Decrypt all files to temp dir preserving relative paths
	for i, e := range pending {
		var data UploadData
		json.Unmarshal([]byte(e.Data), &data)

		if i%50 == 0 {
			log(fmt.Sprintf("Decrypting %d of %d...", i+1, len(pending)))
		}

		relPath := data.RelPath
		if relPath == "" {
			relPath = e.Value
		}
		outPath := filepath.Join(tempDir, relPath)
		os.MkdirAll(filepath.Dir(outPath), 0755)

		content, err := lib.DecryptFile(data.Path)
		if err != nil {
			continue
		}
		os.WriteFile(outPath, content, 0644)

		data.Status = "processing"
		dataJSON, _ := json.Marshal(data)
		e.Data = string(dataJSON)
		lib.EntryWrite(nil, e)
	}
	log("Decryption complete, running import-dicom")

	// Run import-dicom synchronously
	cmd := exec.Command("/tank/inou/bin/import-dicom", targetID, tempDir)
	output, cmdErr := cmd.CombinedOutput()
	log(fmt.Sprintf("import-dicom output: %s", string(output)))

	// Update all entries based on result
	status := "processed"
	if cmdErr != nil {
		status = "failed"
	}

	for _, e := range pending {
		var data UploadData
		json.Unmarshal([]byte(e.Data), &data)
		data.Status = status
		dataJSON, _ := json.Marshal(data)
		e.Data = string(dataJSON)
		lib.EntryWrite(nil, e)
	}

	// Log result
	lib.AuditLog(p.DossierID, "dicom_import", targetID, fmt.Sprintf("files=%d status=%s", len(pending), status))

	w.Header().Set("Content-Type", "application/json")
	if cmdErr != nil {
		log(fmt.Sprintf("Import failed: %v", cmdErr))
		w.Write([]byte(fmt.Sprintf(`{"status":"error","message":"Import failed: %v"}`, cmdErr)))
	} else {
		log(fmt.Sprintf("Import success: %d files", len(pending)))
		w.Write([]byte(fmt.Sprintf(`{"status":"ok","message":"Successfully imported %d files"}`, len(pending))))
	}
}