package web

import (
	"bytes"
	"encoding/csv"
	"fmt"
	"io"
	"log"
	"mime/multipart"
	"net/http"
	"path/filepath"
	"regexp"
	"strconv"
	"strings"
	"time"

	root "marmic/servicetrade-toolbox"
	"marmic/servicetrade-toolbox/internal/api"
)

// DocumentsHandler handles the document upload page
func DocumentsHandler(w http.ResponseWriter, r *http.Request) {
	session, ok := r.Context().Value("session").(*api.Session)
	if !ok {
		http.Error(w, "Unauthorized", http.StatusUnauthorized)
		return
	}

	tmpl := root.WebTemplates
	data := map[string]interface{}{
		"Title":   "Document Uploads",
		"Session": session,
	}

	if r.Header.Get("HX-Request") == "true" {
		// For HTMX requests, just send the document_upload partial
		if err := tmpl.ExecuteTemplate(w, "document_upload", data); err != nil {
			log.Printf("Template execution error: %v", err)
			http.Error(w, "Internal Server Error", http.StatusInternalServerError)
			return
		}
	} else {
		// For full page requests, first render document_upload into a buffer
		var contentBuf bytes.Buffer
		if err := tmpl.ExecuteTemplate(&contentBuf, "document_upload", data); err != nil {
			log.Printf("Template execution error: %v", err)
			http.Error(w, "Internal Server Error", http.StatusInternalServerError)
			return
		}

		// Add the rendered content to the data for the layout
		data["BodyContent"] = contentBuf.String()

		// Now render the layout with our content
		if err := tmpl.ExecuteTemplate(w, "layout.html", data); err != nil {
			log.Printf("Template execution error: %v", err)
			http.Error(w, "Internal Server Error", http.StatusInternalServerError)
			return
		}
	}
}

// ProcessCSVHandler processes a CSV file with job numbers
func ProcessCSVHandler(w http.ResponseWriter, r *http.Request) {
	_, ok := r.Context().Value("session").(*api.Session)
	if !ok {
		http.Error(w, "Unauthorized", http.StatusUnauthorized)
		return
	}

	// Check if the request method is POST
	if r.Method != http.MethodPost {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	// Parse the multipart form data with a 10MB limit
	if err := r.ParseMultipartForm(10 << 20); err != nil {
		http.Error(w, "Unable to parse form: "+err.Error(), http.StatusBadRequest)
		return
	}

	// Get the file from the form
	file, _, err := r.FormFile("csvFile")
	if err != nil {
		http.Error(w, "Error retrieving file: "+err.Error(), http.StatusBadRequest)
		return
	}
	defer file.Close()

	// Read the CSV data
	csvData, err := csv.NewReader(file).ReadAll()
	if err != nil {
		http.Error(w, "Error reading CSV file: "+err.Error(), http.StatusBadRequest)
		return
	}

	if len(csvData) < 2 {
		http.Error(w, "CSV file must contain at least a header row and one data row", http.StatusBadRequest)
		return
	}

	// Find the index of the 'id' column
	headerRow := csvData[0]
	idColumnIndex := -1
	for i, header := range headerRow {
		if strings.ToLower(strings.TrimSpace(header)) == "id" {
			idColumnIndex = i
			break
		}
	}

	// If 'id' column not found, try the first column
	if idColumnIndex == -1 {
		idColumnIndex = 0
		log.Printf("No 'id' column found in CSV, using first column (header: %s)", headerRow[0])
	} else {
		log.Printf("Found 'id' column at index %d", idColumnIndex)
	}

	// Extract job numbers from the CSV
	var jobNumbers []string
	for rowIndex, row := range csvData {
		// Skip header row
		if rowIndex == 0 {
			continue
		}

		if len(row) > idColumnIndex {
			// Extract and clean up the job ID
			jobID := strings.TrimSpace(row[idColumnIndex])
			if jobID != "" {
				jobNumbers = append(jobNumbers, jobID)
				log.Printf("Added job ID: %s", jobID)
			}
		}
	}

	log.Printf("Extracted %d job IDs from CSV", len(jobNumbers))

	// Create a list of valid job numbers
	var validJobNumbers []string
	validJobNumbers = append(validJobNumbers, jobNumbers...)

	// Generate HTML for job list
	var jobListHTML string
	if len(validJobNumbers) > 0 {
		// Create a hidden input with the job IDs
		jobsValue := strings.Join(validJobNumbers, ",")

		// Insert a hidden input for job numbers and show the job list
		jobListHTML = fmt.Sprintf(`
			<input type="hidden" name="jobNumbers" value="%s">
			
			<style>
				#csv-preview { display: block !important; }
			</style>
			
			<script>
				// Update the job list display
				document.getElementById("csv-preview-content").innerHTML = '';
				var ul = document.createElement("ul");
				ul.className = "job-list";
				%s
				document.getElementById("csv-preview-content").appendChild(ul);
			</script>
		`, jobsValue, buildJobListJS(validJobNumbers))
	} else {
		jobListHTML = `
			<p>No valid job numbers found in the CSV file.</p>
		`
	}

	w.Header().Set("Content-Type", "text/html")
	w.Write([]byte(jobListHTML))
}

// Helper function to build JavaScript for job list
func buildJobListJS(jobIDs []string) string {
	var js strings.Builder
	for _, id := range jobIDs {
		js.WriteString(fmt.Sprintf(`
			var li = document.createElement("li");
			li.setAttribute("data-job-id", "%s");
			li.textContent = "Job #%s";
			ul.appendChild(li);
		`, id, id))
	}
	return js.String()
}

// UploadDocumentsHandler handles document uploads to jobs
func UploadDocumentsHandler(w http.ResponseWriter, r *http.Request) {
	session, ok := r.Context().Value("session").(*api.Session)
	if !ok {
		http.Error(w, "Unauthorized", http.StatusUnauthorized)
		return
	}

	// Check if the request method is POST
	if r.Method != http.MethodPost {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	// Parse the multipart form with a 30MB limit
	if err := r.ParseMultipartForm(30 << 20); err != nil {
		http.Error(w, fmt.Sprintf("Unable to parse form: %v", err), http.StatusBadRequest)
		return
	}

	// Get the job numbers from either of the possible form fields
	jobNumbers := r.FormValue("jobNumbers")
	if jobNumbers == "" {
		jobNumbers = r.FormValue("job-ids")
		if jobNumbers == "" {
			log.Printf("No job numbers provided. Form data: %+v", r.Form)
			http.Error(w, "No job numbers provided", http.StatusBadRequest)
			return
		}
	}

	// Log the form data for debugging
	log.Printf("Form data: %+v", r.Form)
	log.Printf("Job numbers: %s", jobNumbers)

	// Split the job numbers
	jobs := strings.Split(jobNumbers, ",")
	if len(jobs) == 0 {
		http.Error(w, "No valid job numbers provided", http.StatusBadRequest)
		return
	}

	// Regular expression to match file field patterns
	filePattern := regexp.MustCompile(`document-file-(\d+)`)

	// Collect document data
	type DocumentData struct {
		File   multipart.File
		Header *multipart.FileHeader
		Name   string
		Type   string
		Index  int
	}

	var documents []DocumentData

	// First, identify all available indices
	var indices []int
	for key := range r.MultipartForm.File {
		if matches := filePattern.FindStringSubmatch(key); len(matches) > 1 {
			if index, err := strconv.Atoi(matches[1]); err == nil {
				indices = append(indices, index)
			}
		}
	}

	// Process each document
	for _, index := range indices {
		fileKey := fmt.Sprintf("document-file-%d", index)
		nameKey := fmt.Sprintf("document-name-%d", index)
		typeKey := fmt.Sprintf("document-type-%d", index)

		fileHeaders := r.MultipartForm.File[fileKey]
		if len(fileHeaders) == 0 {
			continue // Skip if no file uploaded
		}

		fileHeader := fileHeaders[0]
		file, err := fileHeader.Open()
		if err != nil {
			log.Printf("Error opening file %s: %v", fileHeader.Filename, err)
			continue
		}

		// Get document name (use filename if not provided)
		documentName := r.FormValue(nameKey)
		if documentName == "" {
			documentName = fileHeader.Filename
		} else {
			// If a custom name is provided without extension, add the original file extension
			if !strings.Contains(documentName, ".") {
				extension := filepath.Ext(fileHeader.Filename)
				if extension != "" {
					documentName = documentName + extension
				}
			}
		}

		log.Printf("Using document name: %s (original filename: %s)", documentName, fileHeader.Filename)

		// Get document type
		documentType := r.FormValue(typeKey)
		if documentType == "" {
			log.Printf("No document type for file %s", fileHeader.Filename)
			continue
		}

		// Log the document type for debugging
		log.Printf("Document type for %s: '%s'", documentName, documentType)

		documents = append(documents, DocumentData{
			File:   file,
			Header: fileHeader,
			Name:   documentName,
			Type:   documentType,
			Index:  index,
		})
	}

	// Process each file and upload to each job
	results := make(map[string][]map[string]interface{})
	for _, doc := range documents {
		defer doc.File.Close()

		// Read file content
		fileContent, err := io.ReadAll(doc.File)
		if err != nil {
			http.Error(w, fmt.Sprintf("Error reading file %s: %v", doc.Header.Filename, err), http.StatusInternalServerError)
			return
		}

		// Upload to each job
		for _, jobID := range jobs {
			// Call the ServiceTrade API
			result, err := session.UploadAttachment(jobID, doc.Name, doc.Type, fileContent)
			if err != nil {
				log.Printf("Error uploading %s to job %s: %v", doc.Name, jobID, err)
				if _, exists := results[jobID]; !exists {
					results[jobID] = []map[string]interface{}{}
				}
				results[jobID] = append(results[jobID], map[string]interface{}{
					"filename": doc.Name,
					"success":  false,
					"error":    err.Error(),
				})
				continue
			}

			// Record the success
			if _, exists := results[jobID]; !exists {
				results[jobID] = []map[string]interface{}{}
			}
			results[jobID] = append(results[jobID], map[string]interface{}{
				"filename": doc.Name,
				"success":  true,
				"data":     result,
			})
			log.Printf("Successfully uploaded %s to job %s", doc.Name, jobID)
		}
	}

	// Generate HTML for results
	var resultHTML bytes.Buffer
	resultHTML.WriteString("<div class='upload-results'>")
	resultHTML.WriteString("<h4>Upload Results</h4>")

	if len(results) == 0 {
		resultHTML.WriteString("<p class='error'>No documents were uploaded. Please check that you have selected files and document types.</p>")
	} else {
		for jobID, jobResults := range results {
			resultHTML.WriteString(fmt.Sprintf("<div class='job-result'><h5>Job #%s</h5><ul>", jobID))

			for _, result := range jobResults {
				filename := result["filename"].(string)
				success := result["success"].(bool)

				if success {
					resultHTML.WriteString(fmt.Sprintf("<li class='success'>%s: Uploaded successfully</li>", filename))
				} else {
					errorMsg := result["error"].(string)
					resultHTML.WriteString(fmt.Sprintf("<li class='error'>%s: %s</li>", filename, errorMsg))
				}
			}

			resultHTML.WriteString("</ul></div>")
		}
	}

	resultHTML.WriteString("</div>")

	// Add JavaScript to scroll to results
	resultHTML.WriteString("<script>document.getElementById('upload-results').scrollIntoView({behavior: 'smooth'});</script>")

	w.Header().Set("Content-Type", "text/html")
	w.Write(resultHTML.Bytes())
}

// DocumentFieldAddHandler generates a new document field for the form
func DocumentFieldAddHandler(w http.ResponseWriter, r *http.Request) {
	// Generate a random ID for the new field
	newId := fmt.Sprintf("%d", time.Now().UnixNano())

	// Create HTML for a new document row
	html := fmt.Sprintf(`
		<div class="document-row" id="document-row-%s">
			<div class="document-field">
				<label>Select Document:</label>
				<input class="card-input" type="file" id="document-file-%s" name="document-file-%s">
			</div>

			<div class="document-field-row">
				<div class="document-field document-name-field">
					<label>Document Name (optional):</label>
					<input class="card-input" type="text" id="document-name-%s" name="document-name-%s"
						placeholder="Document Name">
				</div>

				<div class="document-field document-type-field">
					<label>Document Type:</label>
					<select class="card-input" id="document-type-%s" name="document-type-%s">
						<option value="">Select Document Type</option>
						<option value="01" selected>Job Paperwork</option>
						<option value="02">Job Vendor Bill</option>
						<option value="07">Generic Attachment</option>
						<option value="10">Blank Paperwork</option>
						<option value="14">Job Invoice</option>
					</select>
				</div>
			</div>

			<button type="button" class="remove-document warning-button"
					hx-get="/document-field-remove?id=%s" 
					hx-target="#document-row-%s"
					hx-swap="outerHTML">Remove</button>
		</div>
	`, newId, newId, newId, newId, newId, newId, newId, newId, newId)

	w.Header().Set("Content-Type", "text/html")
	w.Write([]byte(html))
}

// DocumentFieldRemoveHandler handles the removal of a document field
func DocumentFieldRemoveHandler(w http.ResponseWriter, r *http.Request) {
	// We read the ID but don't need to use it for simple removal
	_ = r.URL.Query().Get("id")

	// Count how many document rows exist
	// For simplicity, we'll just return an empty response to remove the field
	// In a complete implementation, we'd check if this is the last field and handle that case

	w.Header().Set("Content-Type", "text/html")
	w.Write([]byte(""))
}