// d2fonts holds fonts for renderings

// TODO write a script to do this as part of CI
// Currently using an online converter: https://dopiaza.org/tools/datauri/index.php
package d2fonts

import (
	"embed"
	"encoding/base64"
	"fmt"
	"os"
	"path/filepath"
	"strings"

	fontlib "oss.terrastruct.com/d2/lib/font"
)

type FontFamily string
type FontStyle string

type Font struct {
	Family FontFamily
	Style  FontStyle
	Size   int
}

func (f FontFamily) Font(size int, style FontStyle) Font {
	return Font{
		Family: f,
		Style:  style,
		Size:   size,
	}
}

func (f Font) GetEncodedSubset(cutset string) string {
	// gofpdf subset only accepts .ttf fonts
	fontBuf := FontFaces[f]
	fontBuf = fontlib.UTF8CutFont(fontBuf, cutset)

	fontBuf, err := fontlib.Sfnt2Woff(fontBuf)
	if err != nil {
		// If subset fails, return full encoding
		return FontEncodings[f]
	}

	return fmt.Sprintf("data:application/font-woff;base64,%v", base64.StdEncoding.EncodeToString(fontBuf))
}

const (
	FONT_SIZE_XS   = 13
	FONT_SIZE_S    = 14
	FONT_SIZE_M    = 16
	FONT_SIZE_L    = 20
	FONT_SIZE_XL   = 24
	FONT_SIZE_XXL  = 28
	FONT_SIZE_XXXL = 32

	FONT_STYLE_REGULAR FontStyle = "regular"
	FONT_STYLE_BOLD    FontStyle = "bold"
	FONT_STYLE_ITALIC  FontStyle = "italic"

	SourceSansPro FontFamily = "SourceSansPro"
	SourceCodePro FontFamily = "SourceCodePro"
	HandDrawn     FontFamily = "HandDrawn"
)

var FontSizes = []int{
	FONT_SIZE_XS,
	FONT_SIZE_S,
	FONT_SIZE_M,
	FONT_SIZE_L,
	FONT_SIZE_XL,
	FONT_SIZE_XXL,
	FONT_SIZE_XXXL,
}

var FontStyles = []FontStyle{
	FONT_STYLE_REGULAR,
	FONT_STYLE_BOLD,
	FONT_STYLE_ITALIC,
}

var FontFamilies = []FontFamily{
	SourceSansPro,
	SourceCodePro,
	HandDrawn,
}

//go:embed encoded/SourceSansPro-Regular.txt
var sourceSansProRegularBase64 string

//go:embed encoded/SourceSansPro-Bold.txt
var sourceSansProBoldBase64 string

//go:embed encoded/SourceSansPro-Italic.txt
var sourceSansProItalicBase64 string

//go:embed encoded/SourceCodePro-Regular.txt
var sourceCodeProRegularBase64 string

//go:embed encoded/SourceCodePro-Bold.txt
var sourceCodeProBoldBase64 string

//go:embed encoded/SourceCodePro-Italic.txt
var sourceCodeProItalicBase64 string

//go:embed encoded/ArchitectsDaughter-Regular.txt
var architectsDaughterRegularBase64 string

//go:embed encoded/FuzzyBubbles-Bold.txt
var fuzzyBubblesBoldBase64 string

//go:embed ttf/*
var fontFacesFS embed.FS

var FontEncodings map[Font]string
var FontFaces map[Font][]byte

func init() {
	FontEncodings = map[Font]string{
		{
			Family: SourceSansPro,
			Style:  FONT_STYLE_REGULAR,
		}: sourceSansProRegularBase64,
		{
			Family: SourceSansPro,
			Style:  FONT_STYLE_BOLD,
		}: sourceSansProBoldBase64,
		{
			Family: SourceSansPro,
			Style:  FONT_STYLE_ITALIC,
		}: sourceSansProItalicBase64,
		{
			Family: SourceCodePro,
			Style:  FONT_STYLE_REGULAR,
		}: sourceCodeProRegularBase64,
		{
			Family: SourceCodePro,
			Style:  FONT_STYLE_BOLD,
		}: sourceCodeProBoldBase64,
		{
			Family: SourceCodePro,
			Style:  FONT_STYLE_ITALIC,
		}: sourceCodeProItalicBase64,
		{
			Family: HandDrawn,
			Style:  FONT_STYLE_REGULAR,
		}: architectsDaughterRegularBase64,
		{
			Family: HandDrawn,
			Style:  FONT_STYLE_ITALIC,
			// This font has no italic, so just reuse regular
		}: architectsDaughterRegularBase64,
		{
			Family: HandDrawn,
			Style:  FONT_STYLE_BOLD,
		}: fuzzyBubblesBoldBase64,
	}

	for k, v := range FontEncodings {
		FontEncodings[k] = strings.TrimSuffix(v, "\n")
	}

	FontFaces = map[Font][]byte{}
	b, err := fontFacesFS.ReadFile("ttf/SourceSansPro-Regular.ttf")
	if err != nil {
		panic(err)
	}
	FontFaces[Font{
		Family: SourceSansPro,
		Style:  FONT_STYLE_REGULAR,
	}] = b
	b, err = fontFacesFS.ReadFile("ttf/SourceCodePro-Regular.ttf")
	if err != nil {
		panic(err)
	}
	FontFaces[Font{
		Family: SourceCodePro,
		Style:  FONT_STYLE_REGULAR,
	}] = b
	b, err = fontFacesFS.ReadFile("ttf/SourceCodePro-Bold.ttf")
	if err != nil {
		panic(err)
	}
	FontFaces[Font{
		Family: SourceCodePro,
		Style:  FONT_STYLE_BOLD,
	}] = b
	b, err = fontFacesFS.ReadFile("ttf/SourceCodePro-Italic.ttf")
	if err != nil {
		panic(err)
	}
	FontFaces[Font{
		Family: SourceCodePro,
		Style:  FONT_STYLE_ITALIC,
	}] = b
	b, err = fontFacesFS.ReadFile("ttf/SourceSansPro-Bold.ttf")
	if err != nil {
		panic(err)
	}
	FontFaces[Font{
		Family: SourceSansPro,
		Style:  FONT_STYLE_BOLD,
	}] = b
	b, err = fontFacesFS.ReadFile("ttf/SourceSansPro-Italic.ttf")
	if err != nil {
		panic(err)
	}
	FontFaces[Font{
		Family: SourceSansPro,
		Style:  FONT_STYLE_ITALIC,
	}] = b
	b, err = fontFacesFS.ReadFile("ttf/ArchitectsDaughter-Regular.ttf")
	if err != nil {
		panic(err)
	}
	FontFaces[Font{
		Family: HandDrawn,
		Style:  FONT_STYLE_REGULAR,
	}] = b
	FontFaces[Font{
		Family: HandDrawn,
		Style:  FONT_STYLE_ITALIC,
	}] = b
	b, err = fontFacesFS.ReadFile("ttf/FuzzyBubbles-Bold.ttf")
	if err != nil {
		panic(err)
	}
	FontFaces[Font{
		Family: HandDrawn,
		Style:  FONT_STYLE_BOLD,
	}] = b
}

func AddFont(fontLoc string) (FontFamily, error) {
	if fontLoc == "" {
		return "", nil
	}
	fontFileName := filepath.Base(fontLoc)

	ext := filepath.Ext(fontFileName)
	if ext != ".ttf" {
		return "", fmt.Errorf("cannot open non .ttf fonts")
	}

	fontBuf, err := os.ReadFile(fontLoc)
	if err != nil {
		return "", fmt.Errorf("failed to read font at location %v", err)
	}

	fontName := strings.TrimSuffix(fontFileName, ext)
	fontFamily := FontFamily(fontName)
	woffFont, err := fontlib.Sfnt2Woff(fontBuf)
	if err != nil {
		return "", fmt.Errorf("failed to convert to woff font: %v", err)
	}

	encodedWoff := fmt.Sprintf("data:application/font-woff;base64,%v", base64.StdEncoding.EncodeToString(woffFont))

	// Encode all styles for now
	customFont := fontFamily.Font(0, FONT_STYLE_REGULAR)
	FontFaces[customFont] = fontBuf
	FontEncodings[customFont] = encodedWoff

	customFont = fontFamily.Font(0, FONT_STYLE_BOLD)
	FontFaces[customFont] = fontBuf
	FontEncodings[customFont] = encodedWoff

	customFont = fontFamily.Font(0, FONT_STYLE_ITALIC)
	FontFaces[customFont] = fontBuf
	FontEncodings[customFont] = encodedWoff

	FontFamilies = append(FontFamilies, fontFamily)
	return fontFamily, nil
}

var D2_FONT_TO_FAMILY = map[string]FontFamily{
	"default": SourceSansPro,
	"mono":    SourceCodePro,
}