package routes

import (
	"fmt"
	"os"
	"path/filepath"
	"strings"

	"github.com/jung-kurt/gofpdf"
)

func resolvePdfAssetPath(file string) (string, error) {

	envMap := map[string]string{
		"DejaVuSans.ttf":      "PDF_FONT_PATH",
		"DejaVuSans-Bold.ttf": "PDF_FONT_BOLD_PATH",
		"FreeSans.ttf":        "PDF_FONT_ALT_PATH",
		"FreeSansBold.ttf":    "PDF_FONT_ALT_BOLD_PATH",
	}

	envKey, ok := envMap[file]
	if !ok {
		return "", fmt.Errorf("unknown font: %s", file)
	}

	path := os.Getenv(envKey)

	if path == "" {
		return "", fmt.Errorf("env %s not set", envKey)
	}

	if _, err := os.Stat(path); err != nil {
		return "", fmt.Errorf("font not found: %s", path)
	}

	return path, nil
}

func resolvePdfImagePath(fileName string) (string, error) {
	return resolveAssetPath(fileName, []string{
		"public",
		filepath.Join("svc", "public"),
	})
}

func resolveAssetPath(fileName string, relativeDirs []string) (string, error) {
	candidates := make([]string, 0, len(relativeDirs)*3)
	for _, dir := range relativeDirs {
		candidates = append(candidates,
			filepath.Join(dir, fileName),
			filepath.Join(".", dir, fileName),
			filepath.Join("..", dir, fileName),
		)
	}

	if exePath, err := os.Executable(); err == nil {
		exeDir := filepath.Dir(exePath)
		for _, dir := range relativeDirs {
			candidates = append(candidates,
				filepath.Join(exeDir, dir, fileName),
				filepath.Join(exeDir, "..", dir, fileName),
			)
		}
	}

	seen := map[string]struct{}{}
	tried := make([]string, 0, len(candidates))

	for _, p := range candidates {
		if abs, err := filepath.Abs(p); err == nil {
			p = abs
		}

		if _, ok := seen[p]; ok {
			continue
		}
		seen[p] = struct{}{}
		tried = append(tried, p)

		if fi, err := os.Stat(p); err == nil && !fi.IsDir() {
			return p, nil
		}
	}

	return "", fmt.Errorf("asset not found: %s (tried: %s)", fileName, strings.Join(tried, ", "))
}

func registerDejavuFonts(pdf *gofpdf.Fpdf, regularFamily, boldFamily string) error {
	regularFont, err := resolvePdfAssetPath("DejaVuSans.ttf")
	if err != nil {
		return err
	}
	boldFont, err := resolvePdfAssetPath("DejaVuSans-Bold.ttf")
	if err != nil {
		return err
	}

	pdf.AddUTF8Font(regularFamily, "", regularFont)
	pdf.AddUTF8Font(boldFamily, "", boldFont)

	if err := pdf.Error(); err != nil {
		return fmt.Errorf("font init failed: %w", err)
	}
	return nil
}