package handlers

import (
	"context"
	"fmt"
	"log"
	"net/http"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"time"

	cvmodel "github.com/juanatsap/cv-site/internal/models/cv"
	uimodel "github.com/juanatsap/cv-site/internal/models/ui"
	"github.com/juanatsap/cv-site/internal/pdf"
	"github.com/juanatsap/cv-site/internal/templates"
)

// CVHandler handles CV-related requests
type CVHandler struct {
	templates    *templates.Manager
	pdfGenerator *pdf.Generator
	serverAddr   string
}

// NewCVHandler creates a new CV handler
func NewCVHandler(tmpl *templates.Manager, serverAddr string) *CVHandler {
	return &CVHandler{
		templates:    tmpl,
		pdfGenerator: pdf.NewGenerator(30 * time.Second),
		serverAddr:   serverAddr,
	}
}

// Home renders the full CV page
func (h *CVHandler) Home(w http.ResponseWriter, r *http.Request) {
	// Check if this is a shortcut URL request (cv-jamr-{year}-{lang}.pdf)
	if strings.HasPrefix(r.URL.Path, "/cv-jamr-") && strings.HasSuffix(r.URL.Path, ".pdf") {
		h.DefaultCVShortcut(w, r)
		return
	}

	// Get language from query parameter, default to English
	lang := r.URL.Query().Get("lang")
	if lang == "" {
		lang = "en"
	}

	// Validate language
	if lang != "en" && lang != "es" {
		HandleError(w, r, BadRequestError("Unsupported language. Use 'en' or 'es'"))
		return
	}

	// Load CV data
	cv, err := cvmodel.LoadCV(lang)
	if err != nil {
		HandleError(w, r, DataLoadError(err, "CV"))
		return
	}

	// Load UI translations
	ui, err := uimodel.LoadUI(lang)
	if err != nil {
		HandleError(w, r, DataLoadError(err, "UI"))
		return
	}

	// Calculate duration for each experience
	for i := range cv.Experience {
		cv.Experience[i].Duration = calculateDuration(
			cv.Experience[i].StartDate,
			cv.Experience[i].EndDate,
			cv.Experience[i].Current,
			lang,
		)
	}

	// Process projects for dynamic dates
	for i := range cv.Projects {
		processProjectDates(&cv.Projects[i], lang)
	}

	// Split skills between left and right sidebars
	skillsLeft, skillsRight := splitSkills(cv.Skills.Technical)

	// Calculate years of experience
	yearsOfExperience := calculateYearsOfExperience()

	// Get current year
	currentYear := time.Now().Year()

	// Read user preferences from cookies
	cvLength := getPreferenceCookie(r, "cv-length", "short")
	cvIcons := getPreferenceCookie(r, "cv-icons", "show")
	cvTheme := getPreferenceCookie(r, "cv-theme", "default")

	// Migrate old preference values to new ones (one-time auto-migration)
	if cvLength == "extended" {
		cvLength = "long"
		setPreferenceCookie(w, "cv-length", "long")
	}
	switch cvIcons {
	case "true":
		cvIcons = "show"
		setPreferenceCookie(w, "cv-icons", "show")
	case "false":
		cvIcons = "hide"
		setPreferenceCookie(w, "cv-icons", "hide")
	}

	// Prepare CV length class
	cvLengthClass := "cv-short"
	if cvLength == "long" {
		cvLengthClass = "cv-long"
	}

	// Prepare template data
	data := map[string]interface{}{
		"CV":                 cv,
		"UI":                 ui,
		"Lang":               lang,
		"SkillsLeft":         skillsLeft,
		"SkillsRight":        skillsRight,
		"YearsOfExperience":  yearsOfExperience,
		"CurrentYear":        currentYear,
		"CanonicalURL":       fmt.Sprintf("https://juan.andres.morenorub.io/?lang=%s", lang),
		"AlternateEN":        "https://juan.andres.morenorub.io/?lang=en",
		"AlternateES":        "https://juan.andres.morenorub.io/?lang=es",
		"CVLengthClass":      cvLengthClass,
		"ShowIcons":          (cvIcons == "show"),
		"ThemeClean":         (cvTheme == "clean"),
	}

	// Render template
	tmpl, err := h.templates.Render("index.html")
	if err != nil {
		HandleError(w, r, TemplateError(err, "index.html"))
		return
	}

	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := tmpl.Execute(w, data); err != nil {
		HandleError(w, r, TemplateError(err, "index.html"))
		return
	}
}

// CVContent renders just the CV content for HTMX swaps
func (h *CVHandler) CVContent(w http.ResponseWriter, r *http.Request) {
	// Get language from query parameter
	lang := r.URL.Query().Get("lang")
	if lang == "" {
		lang = "en"
	}

	// Validate language
	if lang != "en" && lang != "es" {
		HandleError(w, r, BadRequestError("Unsupported language. Use 'en' or 'es'"))
		return
	}

	// Load CV data
	cv, err := cvmodel.LoadCV(lang)
	if err != nil {
		HandleError(w, r, DataLoadError(err, "CV"))
		return
	}

	// Load UI translations
	ui, err := uimodel.LoadUI(lang)
	if err != nil {
		HandleError(w, r, DataLoadError(err, "UI"))
		return
	}

	// Calculate duration for each experience
	for i := range cv.Experience {
		cv.Experience[i].Duration = calculateDuration(
			cv.Experience[i].StartDate,
			cv.Experience[i].EndDate,
			cv.Experience[i].Current,
			lang,
		)
	}

	// Process projects for dynamic dates
	for i := range cv.Projects {
		processProjectDates(&cv.Projects[i], lang)
	}

	// Split skills between left and right sidebars
	skillsLeft, skillsRight := splitSkills(cv.Skills.Technical)

	// Calculate years of experience
	yearsOfExperience := calculateYearsOfExperience()

	// Get current year
	currentYear := time.Now().Year()

	// Prepare template data
	data := map[string]interface{}{
		"CV":                 cv,
		"UI":                 ui,
		"Lang":               lang,
		"SkillsLeft":         skillsLeft,
		"SkillsRight":        skillsRight,
		"YearsOfExperience":  yearsOfExperience,
		"CurrentYear":        currentYear,
		"CanonicalURL":       fmt.Sprintf("https://juan.andres.morenorub.io/?lang=%s", lang),
		"AlternateEN":        "https://juan.andres.morenorub.io/?lang=en",
		"AlternateES":        "https://juan.andres.morenorub.io/?lang=es",
	}

	// Render template
	tmpl, err := h.templates.Render("cv-content.html")
	if err != nil {
		HandleError(w, r, TemplateError(err, "cv-content.html"))
		return
	}

	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := tmpl.Execute(w, data); err != nil {
		HandleError(w, r, TemplateError(err, "cv-content.html"))
		return
	}
}

// DefaultCVShortcut handles shortcut URLs for default CV downloads
// Pattern: /cv-jamr-{year}-{lang}.pdf (e.g., /cv-jamr-2025-en.pdf)
// Validates year matches current year and redirects to default PDF export
func (h *CVHandler) DefaultCVShortcut(w http.ResponseWriter, r *http.Request) {
	// Extract path (e.g., "/cv-jamr-2025-en.pdf")
	path := r.URL.Path
	log.Printf("DefaultCVShortcut called with path: %s", path)

	// Parse filename pattern: cv-jamr-{year}-{lang}.pdf
	parts := strings.Split(strings.TrimPrefix(path, "/"), "-")
	if len(parts) != 4 {
		http.NotFound(w, r)
		return
	}

	// Extract year and language
	yearStr := parts[2]
	langWithExt := parts[3] // "en.pdf" or "es.pdf"
	lang := strings.TrimSuffix(langWithExt, ".pdf")

	// Validate language
	if lang != "en" && lang != "es" {
		http.NotFound(w, r)
		return
	}

	// Validate year matches current year
	currentYear := fmt.Sprintf("%d", time.Now().Year())
	if yearStr != currentYear {
		// Return 404 if year doesn't match (old or future URLs)
		log.Printf("Invalid year in shortcut URL: %s (current: %s)", yearStr, currentYear)
		http.NotFound(w, r)
		return
	}

	// Generate PDF directly instead of redirecting
	// This ensures the Content-Disposition filename is respected by browsers
	log.Printf("Shortcut URL: %s → generating PDF (short + with_skills)", path)

	// Prepare cookies for PDF generation (short, with_skills, light mode)
	cookies := map[string]string{
		"cv-length":    "short",
		"cv-icons":     "show",
		"cv-language":  lang,
		"cv-theme":     "default", // with_skills = default theme
		"color-theme":  "light",   // Always light for PDFs
	}

	// Construct URL for PDF generation
	targetURL := fmt.Sprintf("http://%s/?lang=%s", h.serverAddr, lang)

	// Generate PDF with screen render mode (for sidebar layout)
	ctx := r.Context()
	pdfData, err := h.pdfGenerator.GenerateFromURLWithOptions(ctx, targetURL, cookies, pdf.RenderModeScreen)
	if err != nil {
		log.Printf("PDF generation failed for shortcut URL: %v", err)
		HandleError(w, r, InternalError(err))
		return
	}

	// Use the shortcut filename directly (simple, user-friendly)
	filename := filepath.Base(path) // cv-jamr-2025-en.pdf

	// Set response headers with shortcut filename
	w.Header().Set("Content-Type", "application/pdf")
	w.Header().Set("Content-Disposition", fmt.Sprintf("attachment; filename=%s", filename))
	w.Header().Set("Content-Length", fmt.Sprintf("%d", len(pdfData)))

	// Write PDF data
	if _, err := w.Write(pdfData); err != nil {
		log.Printf("Error writing PDF response: %v", err)
		return
	}

	log.Printf("PDF generated successfully: %s (%d bytes)", filename, len(pdfData))
}

// ExportPDF handles PDF export requests using chromedp
func (h *CVHandler) ExportPDF(w http.ResponseWriter, r *http.Request) {
	// Extract and validate query parameters
	lang := r.URL.Query().Get("lang")
	if lang == "" {
		lang = "en"
	}
	if lang != "en" && lang != "es" {
		HandleError(w, r, BadRequestError("Unsupported language. Use 'en' or 'es'"))
		return
	}

	length := r.URL.Query().Get("length")
	if length == "" {
		length = "short"
	}
	if length != "short" && length != "long" {
		HandleError(w, r, BadRequestError("Unsupported length. Use 'short' or 'long'"))
		return
	}

	icons := r.URL.Query().Get("icons")
	if icons == "" {
		icons = "show"
	}
	if icons != "show" && icons != "hide" {
		HandleError(w, r, BadRequestError("Unsupported icons option. Use 'show' or 'hide'"))
		return
	}

	version := r.URL.Query().Get("version")
	if version == "" {
		version = "with_skills"
	}
	if version != "with_skills" && version != "clean" {
		HandleError(w, r, BadRequestError("Unsupported version. Use 'with_skills' or 'clean'"))
		return
	}

	log.Printf("PDF export requested: lang=%s, length=%s, icons=%s, version=%s", lang, length, icons, version)

	// Load CV data to get name for filename
	cv, err := cvmodel.LoadCV(lang)
	if err != nil {
		HandleError(w, r, DataLoadError(err, "CV"))
		return
	}

	// Prepare cookies to set preferences
	cookies := map[string]string{
		"cv-length":   length,
		"cv-icons":    icons,
		"cv-language": lang,
	}

	// Set theme cookie based on version parameter
	if version == "clean" {
		cookies["cv-theme"] = "clean"
	} else {
		cookies["cv-theme"] = "default"
	}

	// CRITICAL: ALWAYS force light mode for PDF generation (print-friendly)
	// This ensures PDFs are NEVER generated in dark mode, regardless of user's preference
	cookies["color-theme"] = "light"

	// Construct URL for PDF generation (navigate to home page)
	targetURL := fmt.Sprintf("http://%s/?lang=%s", h.serverAddr, lang)

	// Determine render mode based on version parameter
	// Clean version: use @media print CSS (print-friendly, no sidebars)
	// Extended version: use @media screen CSS (full layout with sidebars)
	var renderMode pdf.RenderMode
	if version == "clean" {
		renderMode = pdf.RenderModePrint
	} else {
		renderMode = pdf.RenderModeScreen
	}

	// Generate PDF with cookies and appropriate render mode
	ctx := r.Context()
	pdfData, err := h.pdfGenerator.GenerateFromURLWithOptions(ctx, targetURL, cookies, renderMode)
	if err != nil {
		log.Printf("PDF generation failed: %v", err)
		HandleError(w, r, InternalError(err))
		return
	}

	// Generate filename based on parameters
	// Format: cv-{length}[-{version}]-{initials}-{year}-{lang}.pdf
	// Note: {version} is OMITTED when it's "clean"
	// Examples:
	//   - cv-short-jamr-2025-es.pdf (clean version, no skills)
	//   - cv-short-with_skills-jamr-2025-es.pdf (with skills sidebar)
	//   - cv-long-jamr-2025-en.pdf (clean version, no skills)
	//   - cv-long-with_skills-jamr-2025-en.pdf (with skills sidebar)

	// Generate initials from name
	nameParts := strings.Fields(cv.Personal.Name)
	initials := ""
	for _, part := range nameParts {
		if len(part) > 0 {
			// Take first letter of each name part
			initials += string([]rune(part)[0])
		}
	}
	initials = strings.ToLower(initials)

	// Get current year
	currentYear := time.Now().Year()

	// Build filename: cv-{length}[-{version}]-{initials}-{year}-{lang}.pdf
	// Omit version if it's "clean"
	// Replace underscores with hyphens in version for filename (with_skills → with-skills)
	var filename string
	if version == "clean" {
		filename = fmt.Sprintf("cv-%s-%s-%d-%s.pdf", length, initials, currentYear, lang)
	} else {
		versionForFilename := strings.ReplaceAll(version, "_", "-")
		filename = fmt.Sprintf("cv-%s-%s-%s-%d-%s.pdf", length, versionForFilename, initials, currentYear, lang)
	}

	// Set response headers
	w.Header().Set("Content-Type", "application/pdf")
	w.Header().Set("Content-Disposition", fmt.Sprintf("attachment; filename=%s", filename))
	w.Header().Set("Content-Length", fmt.Sprintf("%d", len(pdfData)))

	// Write PDF data
	if _, err := w.Write(pdfData); err != nil {
		log.Printf("Error writing PDF response: %v", err)
		return
	}

	log.Printf("PDF generated successfully: %s (%d bytes)", filename, len(pdfData))
}

// splitSkills splits skill categories between left (page 1) and right (page 2) sidebars
// Each category explicitly specifies which sidebar it belongs to via the "sidebar" field
func splitSkills(skills []cvmodel.SkillCategory) (left, right []cvmodel.SkillCategory) {
	if len(skills) == 0 {
		return nil, nil
	}

	// Filter by sidebar field
	for _, skill := range skills {
		if skill.Sidebar == "right" {
			right = append(right, skill)
		} else {
			// Default to left if not specified or if set to "left"
			left = append(left, skill)
		}
	}

	return left, right
}

// calculateYearsOfExperience calculates years of experience since April 1, 2005
// This matches the original React implementation that calculated from 01/04/2005
func calculateYearsOfExperience() int {
	// First day at work: April 1, 2005
	firstDay := time.Date(2005, time.April, 1, 9, 0, 0, 0, time.UTC)

	// Current date
	now := time.Now()

	// Calculate the difference in years
	years := now.Year() - firstDay.Year()

	// Adjust if we haven't reached the anniversary this year yet
	if now.Month() < firstDay.Month() ||
	   (now.Month() == firstDay.Month() && now.Day() < firstDay.Day()) {
		years--
	}

	return years
}

// calculateDuration calculates the duration between two dates in years and months
// Date format expected: "YYYY-MM" (e.g., "2021-01")
// Returns a formatted string like "3 years 6 months" or "6 months"
func calculateDuration(startDate, endDate string, current bool, lang string) string {
	// Parse start date
	start, err := time.Parse("2006-01", startDate)
	if err != nil {
		return ""
	}

	// Determine end date
	var end time.Time
	if current {
		end = time.Now()
	} else {
		end, err = time.Parse("2006-01", endDate)
		if err != nil {
			return ""
		}
	}

	// Calculate total months
	totalMonths := (end.Year()-start.Year())*12 + int(end.Month()-start.Month())

	// If end date is before start date, return empty
	if totalMonths < 0 {
		return ""
	}

	years := totalMonths / 12
	months := totalMonths % 12

	// Format the duration string based on language
	var result string
	if lang == "es" {
		if years > 0 && months > 0 {
			yearStr := "años"
			if years == 1 {
				yearStr = "año"
			}
			monthStr := "meses"
			if months == 1 {
				monthStr = "mes"
			}
			result = fmt.Sprintf("(%d %s %d %s)", years, yearStr, months, monthStr)
		} else if years > 0 {
			yearStr := "años"
			if years == 1 {
				yearStr = "año"
			}
			result = fmt.Sprintf("(%d %s)", years, yearStr)
		} else {
			monthStr := "meses"
			if months == 1 {
				monthStr = "mes"
			}
			result = fmt.Sprintf("(%d %s)", months, monthStr)
		}
	} else {
		if years > 0 && months > 0 {
			yearStr := "years"
			if years == 1 {
				yearStr = "year"
			}
			monthStr := "months"
			if months == 1 {
				monthStr = "month"
			}
			result = fmt.Sprintf("(%d %s %d %s)", years, yearStr, months, monthStr)
		} else if years > 0 {
			yearStr := "years"
			if years == 1 {
				yearStr = "year"
			}
			result = fmt.Sprintf("(%d %s)", years, yearStr)
		} else {
			monthStr := "months"
			if months == 1 {
				monthStr = "month"
			}
			result = fmt.Sprintf("(%d %s)", months, monthStr)
		}
	}

	return result
}

// processProjectDates calculates dynamic dates for projects
// If a project has a gitRepoUrl, it fetches the first commit date
// For current projects, it sets the current system date
func processProjectDates(project *cvmodel.Project, lang string) {
	now := time.Now()

	// Set dynamic current date for ongoing projects
	if project.Current {
		if lang == "es" {
			project.DynamicDate = "Presente"
		} else {
			project.DynamicDate = "Present"
		}
	}

	// If project has a git repository URL, fetch the first commit date
	if project.GitRepoUrl != "" {
		commitDate := getGitRepoFirstCommitDate(project.GitRepoUrl)
		if commitDate != "" {
			project.ComputedStartDate = commitDate
		}
	}

	// If no computed date and no static date, use current date for current projects
	if project.ComputedStartDate == "" && project.StartDate == "" && project.Current {
		project.ComputedStartDate = now.Format("2006-01")
	}

	// If we have a computed date but no static date, use the computed one
	if project.ComputedStartDate != "" && project.StartDate == "" {
		project.StartDate = project.ComputedStartDate
	}
}

// findProjectRoot finds the project root directory
// It looks for .git directory walking up the directory tree
func findProjectRoot() (string, error) {
	// Start from current working directory
	cwd, err := os.Getwd()
	if err != nil {
		return "", err
	}

	// Walk up the directory tree looking for .git
	dir := cwd
	for {
		gitPath := filepath.Join(dir, ".git")
		if info, err := os.Stat(gitPath); err == nil && info.IsDir() {
			// Found .git directory - this is the project root
			return dir, nil
		}

		// Move up one directory
		parent := filepath.Dir(dir)
		if parent == dir {
			// Reached root directory without finding .git
			// Fall back to current working directory
			return cwd, nil
		}
		dir = parent
	}
}

// validateRepoPath validates that a repository path is safe to use
// Security: Prevents path traversal and command injection attacks
// Only allows paths within the project directory
func validateRepoPath(path string) error {
	// Resolve to absolute path to prevent path traversal
	absPath, err := filepath.Abs(path)
	if err != nil {
		return fmt.Errorf("invalid path: %w", err)
	}

	// Get project root directory - find the git repo root
	// This ensures the validation works regardless of where code runs from
	projectRoot, err := findProjectRoot()
	if err != nil {
		return fmt.Errorf("cannot determine project root: %w", err)
	}

	// Security check: Only allow paths within project directory
	// This prevents malicious paths like "../../../etc/passwd"
	if !strings.HasPrefix(absPath, projectRoot) {
		return fmt.Errorf("repository path outside project directory: %s", path)
	}

	// Verify path exists and is a directory
	info, err := os.Stat(absPath)
	if err != nil {
		return fmt.Errorf("path does not exist: %w", err)
	}
	if !info.IsDir() {
		return fmt.Errorf("path is not a directory: %s", path)
	}

	return nil
}

// getGitRepoFirstCommitDate fetches the first commit date from a git repository
// Supports local git repository paths
// Security: Validates path and uses timeout to prevent hanging
func getGitRepoFirstCommitDate(repoPath string) string {
	// Security: Validate repository path before executing git command
	if err := validateRepoPath(repoPath); err != nil {
		log.Printf("Security: Rejected git operation for invalid path %s: %v", repoPath, err)
		return ""
	}

	// Security: Add timeout context to prevent hanging
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	// Execute git command with timeout protection
	// Using CommandContext for automatic cancellation on timeout
	cmd := exec.CommandContext(ctx, "git", "-C", repoPath, "log", "--reverse", "--format=%ci", "--date=format:%Y-%m")

	output, err := cmd.Output()
	if err != nil {
		// Log error but don't expose details to prevent information disclosure
		log.Printf("Git command failed for path %s: %v", repoPath, err)
		return ""
	}

	// Parse the output to get the first commit date
	lines := strings.Split(strings.TrimSpace(string(output)), "\n")
	if len(lines) == 0 {
		return ""
	}

	// Extract YYYY-MM from the first commit timestamp
	// Format of output: "2024-06-15 10:30:45 +0200"
	firstLine := lines[0]
	parts := strings.Fields(firstLine)
	if len(parts) > 0 {
		datePart := parts[0] // "2024-06-15"
		dateParts := strings.Split(datePart, "-")
		if len(dateParts) >= 2 {
			return dateParts[0] + "-" + dateParts[1] // "2024-06"
		}
	}

	return ""
}

// ==============================================================================
// HTMX ENDPOINTS - Phase 2
// ==============================================================================

// prepareTemplateData prepares common template data used across handlers
func (h *CVHandler) prepareTemplateData(lang string) (map[string]interface{}, error) {
	// Load CV data
	cv, err := cvmodel.LoadCV(lang)
	if err != nil {
		return nil, err
	}

	// Load UI translations
	ui, err := uimodel.LoadUI(lang)
	if err != nil {
		return nil, err
	}

	// Calculate duration for each experience
	for i := range cv.Experience {
		cv.Experience[i].Duration = calculateDuration(
			cv.Experience[i].StartDate,
			cv.Experience[i].EndDate,
			cv.Experience[i].Current,
			lang,
		)
	}

	// Process projects for dynamic dates
	for i := range cv.Projects {
		processProjectDates(&cv.Projects[i], lang)
	}

	// Split skills between left and right sidebars
	skillsLeft, skillsRight := splitSkills(cv.Skills.Technical)

	// Calculate years of experience
	yearsOfExperience := calculateYearsOfExperience()

	// Get current year
	currentYear := time.Now().Year()

	// Prepare template data
	data := map[string]interface{}{
		"CV":                 cv,
		"UI":                 ui,
		"Lang":               lang,
		"SkillsLeft":         skillsLeft,
		"SkillsRight":        skillsRight,
		"YearsOfExperience":  yearsOfExperience,
		"CurrentYear":        currentYear,
		"CanonicalURL":       fmt.Sprintf("https://juan.andres.morenorub.io/?lang=%s", lang),
		"AlternateEN":        "https://juan.andres.morenorub.io/?lang=en",
		"AlternateES":        "https://juan.andres.morenorub.io/?lang=es",
	}

	return data, nil
}

// getPreferenceCookie gets a preference cookie value, returns default if not found
func getPreferenceCookie(r *http.Request, name string, defaultValue string) string {
	cookie, err := r.Cookie(name)
	if err != nil {
		return defaultValue
	}
	return cookie.Value
}

// setPreferenceCookie sets a preference cookie (1 year expiry)
func setPreferenceCookie(w http.ResponseWriter, name string, value string) {
	http.SetCookie(w, &http.Cookie{
		Name:     name,
		Value:    value,
		Path:     "/",
		MaxAge:   365 * 24 * 60 * 60, // 1 year
		HttpOnly: true,
		SameSite: http.SameSiteStrictMode,
		Secure:   false, // Set to true in production with HTTPS
	})
}

// ToggleLength handles CV length toggle (short/long) using atomic out-of-band swaps
func (h *CVHandler) ToggleLength(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	// Get current state
	currentLength := getPreferenceCookie(r, "cv-length", "short")

	// Migrate old value if needed
	if currentLength == "extended" {
		currentLength = "long"
	}

	// Toggle state
	newLength := "long"
	if currentLength == "long" {
		newLength = "short"
	}

	// Save new state
	setPreferenceCookie(w, "cv-length", newLength)

	// Get language
	lang := r.URL.Query().Get("lang")
	if lang == "" {
		lang = getPreferenceCookie(r, "cv-language", "en")
	}

	// Prepare template data with length state
	cvLengthClass := "cv-short"
	if newLength == "long" {
		cvLengthClass = "cv-long"
	}

	data := map[string]interface{}{
		"Lang":          lang,
		"CVLengthClass": cvLengthClass,
	}

	// Render length-toggle template with out-of-band swaps
	tmpl, err := h.templates.Render("length-toggle.html")
	if err != nil {
		HandleError(w, r, TemplateError(err, "length-toggle.html"))
		return
	}

	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := tmpl.Execute(w, data); err != nil {
		HandleError(w, r, TemplateError(err, "length-toggle.html"))
		return
	}
}

// ToggleIcons handles icon visibility toggle using atomic out-of-band swaps
func (h *CVHandler) ToggleIcons(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	// Get current state
	currentIcons := getPreferenceCookie(r, "cv-icons", "show")

	// Migrate old values if needed
	switch currentIcons {
	case "true":
		currentIcons = "show"
	case "false":
		currentIcons = "hide"
	}

	// Toggle state
	newIcons := "hide"
	if currentIcons == "hide" {
		newIcons = "show"
	}

	// Save new state
	setPreferenceCookie(w, "cv-icons", newIcons)

	// Get language
	lang := r.URL.Query().Get("lang")
	if lang == "" {
		lang = getPreferenceCookie(r, "cv-language", "en")
	}

	// Prepare template data with logo state
	data := map[string]interface{}{
		"Lang":      lang,
		"ShowIcons": (newIcons == "show"),
	}

	// Render logo-toggle template with out-of-band swaps
	tmpl, err := h.templates.Render("logo-toggle.html")
	if err != nil {
		HandleError(w, r, TemplateError(err, "logo-toggle.html"))
		return
	}

	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := tmpl.Execute(w, data); err != nil {
		HandleError(w, r, TemplateError(err, "logo-toggle.html"))
		return
	}
}

// SwitchLanguage handles language switching with atomic updates
// Uses HTMX out-of-band swaps to update both the language selector buttons
// and all CV content wrappers in a single response
func (h *CVHandler) SwitchLanguage(w http.ResponseWriter, r *http.Request) {
	// Get language from query parameter
	lang := r.URL.Query().Get("lang")
	if lang == "" {
		lang = "en"
	}

	// Validate language
	if lang != "en" && lang != "es" {
		HandleError(w, r, BadRequestError("Unsupported language. Use 'en' or 'es'"))
		return
	}

	// Save language preference
	setPreferenceCookie(w, "cv-language", lang)

	// Prepare template data
	data, err := h.prepareTemplateData(lang)
	if err != nil {
		HandleError(w, r, DataLoadError(err, "CV"))
		return
	}

	// Preserve current length and logo preferences
	cvLength := getPreferenceCookie(r, "cv-length", "short")
	cvIcons := getPreferenceCookie(r, "cv-icons", "show")
	cvTheme := getPreferenceCookie(r, "cv-theme", "default")

	// Add preferences to data
	if cvLength == "long" {
		data["CVLengthClass"] = "cv-long"
	} else {
		data["CVLengthClass"] = "cv-short"
	}
	data["ShowIcons"] = (cvIcons == "show")
	data["ThemeClean"] = (cvTheme == "clean")

	// Render language-switch template with out-of-band swaps
	tmpl, err := h.templates.Render("language-switch.html")
	if err != nil {
		HandleError(w, r, TemplateError(err, "language-switch.html"))
		return
	}

	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := tmpl.Execute(w, data); err != nil {
		HandleError(w, r, TemplateError(err, "language-switch.html"))
		return
	}
}

// ToggleTheme handles theme toggle (default/clean) using atomic out-of-band swaps
func (h *CVHandler) ToggleTheme(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	// Get current state
	currentTheme := getPreferenceCookie(r, "cv-theme", "default")

	// Toggle state
	newTheme := "clean"
	if currentTheme == "clean" {
		newTheme = "default"
	}

	// Save new state
	setPreferenceCookie(w, "cv-theme", newTheme)

	// Get language
	lang := r.URL.Query().Get("lang")
	if lang == "" {
		lang = getPreferenceCookie(r, "cv-language", "en")
	}

	// Prepare template data with theme state
	data := map[string]interface{}{
		"Lang":        lang,
		"ThemeClean":  (newTheme == "clean"),
	}

	// Render theme-toggle template with out-of-band swaps
	tmpl, err := h.templates.Render("theme-toggle.html")
	if err != nil {
		HandleError(w, r, TemplateError(err, "theme-toggle.html"))
		return
	}

	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := tmpl.Execute(w, data); err != nil {
		HandleError(w, r, TemplateError(err, "theme-toggle.html"))
		return
	}
}