doomer/doomer.go

package main

import (
	"fmt"
	"log"
	"strings"

	"github.com/fogleman/gg"
	"golang.org/x/image/font"
	database "nefrace.ru/doomer/db"
)

type Doomer struct {
	Face   font.Face
	db     *database.Db
	Border int
}

func NewDoomer(db *database.Db) *Doomer {
	face, err := gg.LoadFontFace("./fonts/AmazDooMLeft.ttf", 108)
	if err != nil {
		log.Fatalf("Error loading font: %v", err)
	}
	return &Doomer{
		Face:   face,
		Border: 12,
		db:     db,
	}
}

func (d *Doomer) GetImage(text string, bgType BackgroundType) (*[]byte, error) {
	hashed := hash(text)
	key := hashed + ":" + fmt.Sprint(bgType)
	store := d.db.Prefix(database.ImageItem)
	img, err := store.GetItem(key)
	if err != nil {
		image, err := d.GenImage(text, bgType)
		if err != nil {
			return nil, err
		}
		store.StoreItem(key, *image)
		img = *image
	}
	return &img, nil
}

func (d *Doomer) GenImage(text string, bgType BackgroundType) (*[]byte, error) {
	textW, textH := d.measureText(text)

	imgW, imgH := int(textW)+d.Border*2, int(textH)+d.Border*2
	ctx := gg.NewContext(imgW, imgH)
	img := NewImage(ctx, bgType, d.Face)
	img.GenText(text)
	return img.ToBytes()
}

func (d *Doomer) measureText(text string) (float64, float64) {
	textctx := gg.NewContext(1, 1)
	textctx.SetFontFace(d.Face)
	textWrapped := textctx.WordWrap(text, 600)
	textW, textH := textctx.MeasureMultilineString(strings.Join(textWrapped, "\n"), 1)
	return textW, textH
}