package owl

import (
	"fmt"
	"io/ioutil"
	"net/url"
	"os"
	"path"
	"sort"
	"time"

	"gopkg.in/yaml.v2"
)

type User struct {
	repo *Repository
	name string
}

type UserConfig struct {
	Title         string `yaml:"title"`
	SubTitle      string `yaml:"subtitle"`
	HeaderColor   string `yaml:"header_color"`
	TwitterHandle string `yaml:"twitter_handle"`
}

func (user User) Dir() string {
	return path.Join(user.repo.UsersDir(), user.name)
}

func (user User) UrlPath() string {
	return user.repo.UserUrlPath(user)
}

func (user User) FullUrl() string {
	url, _ := url.JoinPath(user.repo.FullUrl(), user.UrlPath())
	return url
}

func (user User) WebmentionUrl() string {
	url, _ := url.JoinPath(user.FullUrl(), "webmention/")
	return url
}

func (user User) PostDir() string {
	return path.Join(user.Dir(), "public")
}

func (user User) MetaDir() string {
	return path.Join(user.Dir(), "meta")
}

func (user User) ConfigFile() string {
	return path.Join(user.MetaDir(), "config.yml")
}

func (user User) Name() string {
	return user.name
}

func (user User) Posts() ([]*Post, error) {
	postFiles := listDir(path.Join(user.Dir(), "public"))
	posts := make([]*Post, 0)
	for _, id := range postFiles {
		// if is a directory and has index.md, add to posts
		if dirExists(path.Join(user.Dir(), "public", id)) {
			if fileExists(path.Join(user.Dir(), "public", id, "index.md")) {
				post, _ := user.GetPost(id)
				posts = append(posts, &post)
			}
		}
	}

	// remove drafts
	n := 0
	for _, post := range posts {
		meta := post.Meta()
		if !meta.Draft {
			posts[n] = post
			n++
		}
	}
	posts = posts[:n]

	type PostWithDate struct {
		post *Post
		date time.Time
	}

	postDates := make([]PostWithDate, len(posts))
	for i, post := range posts {
		meta := post.Meta()
		date, err := time.Parse(time.RFC1123Z, meta.Date)
		if err != nil {
			// invalid date -> use 1970-01-01
			date = time.Time{}
		}
		postDates[i] = PostWithDate{post: post, date: date}
	}

	// sort posts by date
	sort.Slice(postDates, func(i, j int) bool {
		return postDates[i].date.After(postDates[j].date)
	})

	for i, post := range postDates {
		posts[i] = post.post
	}

	return posts, nil
}

func (user User) GetPost(id string) (Post, error) {
	// check if posts index.md exists
	if !fileExists(path.Join(user.Dir(), "public", id, "index.md")) {
		return Post{}, fmt.Errorf("post %s does not exist", id)
	}

	post := Post{user: &user, id: id}
	// post.loadMeta()
	meta := post.Meta()
	title := meta.Title
	post.title = fmt.Sprint(title)

	return post, nil
}

func (user User) CreateNewPost(title string) (Post, error) {
	timestamp := time.Now().UTC().Unix()
	folder_name := fmt.Sprintf("%d-%s", timestamp, title)
	post_dir := path.Join(user.Dir(), "public", folder_name)

	// if post already exists, add -n to the end of the name
	i := 0
	for {
		if dirExists(post_dir) {
			i++
			folder_name = fmt.Sprintf("%d-%s-%d", timestamp, title, i)
			post_dir = path.Join(user.Dir(), "public", folder_name)
		} else {
			break
		}
	}
	post := Post{user: &user, id: folder_name, title: title}

	initial_content := ""
	initial_content += "---\n"
	initial_content += "title: " + title + "\n"
	initial_content += "date: " + time.Now().UTC().Format(time.RFC1123Z) + "\n"
	initial_content += "---\n"
	initial_content += "\n"
	initial_content += "Write your post here.\n"

	// create post file
	os.Mkdir(post_dir, 0755)
	os.WriteFile(post.ContentFile(), []byte(initial_content), 0644)
	// create media dir
	os.Mkdir(post.MediaDir(), 0755)
	os.Mkdir(post.WebmentionDir(), 0755)
	return post, nil
}

func (user User) Template() (string, error) {
	// load base.html
	path := path.Join(user.Dir(), "meta", "base.html")
	base_html, err := ioutil.ReadFile(path)
	if err != nil {
		return "", err
	}
	return string(base_html), nil
}

func (user User) Config() (UserConfig, error) {
	config_path := user.ConfigFile()
	config_data, err := ioutil.ReadFile(config_path)
	if err != nil {
		return UserConfig{}, err
	}
	var meta UserConfig
	err = yaml.Unmarshal(config_data, &meta)
	if err != nil {
		return UserConfig{}, err
	}
	return meta, nil
}

func (user User) SetConfig(new_config UserConfig) error {
	config_path := user.ConfigFile()
	config_data, err := yaml.Marshal(new_config)
	if err != nil {
		return err
	}
	err = ioutil.WriteFile(config_path, config_data, 0644)
	if err != nil {
		return err
	}
	return nil
}

func (user User) PostAliases() (map[string]*Post, error) {
	post_aliases := make(map[string]*Post)
	posts, err := user.Posts()
	if err != nil {
		return post_aliases, err
	}
	for _, post := range posts {
		if err != nil {
			return post_aliases, err
		}
		for _, alias := range post.Aliases() {
			post_aliases[alias] = post
		}
	}
	return post_aliases, nil
}