package main

import (
	"bytes"
	"errors"
	"gopkg.in/yaml.v2"
)

type HugoFrontmatter struct {
	Title          string                  `yaml:"title,omitempty"`
	Date           string                  `yaml:"date,omitempty"`
	Lastmod        string                  `yaml:"lastmod,omitempty"`
	Tags           []string                `yaml:"tags,omitempty"`
	ExternalURL    string                  `yaml:"externalURL,omitempty"`
	Indieweb       HugoFrontmatterIndieweb `yaml:"indieweb,omitempty"`
	Syndicate      []string                `yaml:"syndicate,omitempty"`
	TranslationKey string                  `yaml:"translationKey,omitempty"`
	Images         []string                `yaml:"images,omitempty"`
	Audio          string                  `yaml:"audio,omitempty"`
}

type HugoFrontmatterIndieweb struct {
	Reply HugoFrontmatterReply `yaml:"reply,omitempty"`
	Like  HugoFrontmatterLike  `yaml:"like,omitempty"`
}

type HugoFrontmatterReply struct {
	Link  string `yaml:"link,omitempty"`
	Title string `yaml:"title,omitempty"`
}

type HugoFrontmatterLike struct {
	Link  string `yaml:"link,omitempty"`
	Title string `yaml:"title,omitempty"`
}

func writeFrontMatter(entry *Entry) (frontmatter string, err error) {
	var buff bytes.Buffer
	writeFrontmatter := &HugoFrontmatter{
		Title:       entry.title,
		Date:        entry.date,
		Lastmod:     entry.lastmod,
		Tags:        entry.tags,
		ExternalURL: entry.link,
		Indieweb: HugoFrontmatterIndieweb{
			Reply: HugoFrontmatterReply{
				Link:  entry.replyLink,
				Title: entry.replyTitle,
			},
			Like: HugoFrontmatterLike{
				Link:  entry.likeLink,
				Title: entry.likeTitle,
			},
		},
		Syndicate:      entry.syndicate,
		TranslationKey: entry.translationKey,
		Audio:          entry.audio,
	}
	for _, image := range entry.images {
		writeFrontmatter.Images = append(writeFrontmatter.Images, image.url)
	}
	yamlBytes, err := yaml.Marshal(&writeFrontmatter)
	if err != nil {
		err = errors.New("failed marshaling frontmatter")
		return
	}
	buff.WriteString("---\n")
	buff.Write(yamlBytes)
	buff.WriteString("---\n")
	frontmatter = buff.String()
	return
}

func WriteHugoPost(entry *Entry) (string, error) {
	var buff bytes.Buffer
	frontmatter, err := writeFrontMatter(entry)
	if err != nil {
		return "", err
	}
	buff.WriteString(frontmatter)
	if len(entry.content) > 0 {
		buff.WriteString(entry.content)
	}
	return buff.String(), nil
}