package handlers

import (
	"fmt"
	"log"
	"net/http"
	"strings"
	"time"

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

// ==============================================================================
// PDF EXPORT HANDLER
// Handles PDF generation with customizable options (length, icons, version, theme)
// ==============================================================================

// ExportPDF handles PDF export requests using chromedp
func (h *CVHandler) ExportPDF(w http.ResponseWriter, r *http.Request) {
	// Parse and validate request parameters
	req, err := ParsePDFExportRequest(r)
	if err != nil {
		HandleError(w, r, BadRequestError(err.Error()))
		return
	}

	log.Printf("PDF export requested: lang=%s, length=%s, icons=%s, version=%s",
		req.Lang, req.Length, req.Icons, req.Version)

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

	// Prepare cookies to set preferences
	cookies := map[string]string{
		"cv-length":   req.Length,
		"cv-icons":    req.Icons,
		"cv-language": req.Lang,
	}

	// Set theme cookie based on version parameter
	if req.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, req.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 req.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 req.Version == "clean" {
		filename = fmt.Sprintf("cv-%s-%s-%d-%s.pdf", req.Length, initials, currentYear, req.Lang)
	} else {
		versionForFilename := strings.ReplaceAll(req.Version, "_", "-")
		filename = fmt.Sprintf("cv-%s-%s-%s-%d-%s.pdf", req.Length, versionForFilename, initials, currentYear, req.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))
}