package plugins

import (
	"fmt"
	"strings"

	"github.com/osteele/gojekyll/tags"
	"github.com/osteele/liquid"
	"github.com/osteele/liquid/render"
)

func init() {
	register("jekyll-avatar", jekyllAvatarPlugin{})
}

type jekyllAvatarPlugin struct{ plugin }

func (p jekyllAvatarPlugin) ConfigureTemplateEngine(e liquid.Engine) error {
	e.RegisterTag("avatar", avatarTag)
	return nil
}

const avatarTemplate = `<img class="avatar avatar-small" src="https://avatars3.githubusercontent.com/{user}?v=3&amp;s=40" alt="{user}" srcset="https://avatars3.githubusercontent.com/{user}?v=3&amp;s=40 1x, https://avatars3.githubusercontent.com/{user}?v=3&amp;s=80 2x, https://avatars3.githubusercontent.com/{user}?v=3&amp;s=120 3x, https://avatars3.githubusercontent.com/{user}?v=3&amp;s=160 4x" width="40" height="40" data-proofer-ignore="true" />`

func avatarTag(ctx render.Context) (string, error) {
	var (
		user string
		size interface{} = 40
	)
	argsline, err := ctx.ExpandTagArg()
	if err != nil {
		return "", err
	}
	args, err := tags.ParseArgs(argsline)
	if err != nil {
		return "", err
	}
	if len(args.Args) > 0 {
		user = args.Args[0]
	}
	options, err := args.EvalOptions(ctx)
	if err != nil {
		return "", err
	}
	for name, value := range options {
		switch name {
		case "user":
			user = fmt.Sprint(value)
		case "size":
			size = value
		default:
			return "", fmt.Errorf("unknown avatar argument: %s", name)
		}
	}
	if user == "" {
		return "", fmt.Errorf("parse error in avatar tag parameters %s", argsline)
	}
	s := strings.Replace(avatarTemplate, "40", fmt.Sprint(size), -1)
	return strings.Replace(s, "{user}", user, -1), nil
}