package post

import (
	"bytes"
	"errors"
	"flag"
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"text/template"
	"time"

	goutil "git.fireandbrimst.one/aw/goutil/misc"
	"git.fireandbrimst.one/aw/wombat/blog"
	gen "git.fireandbrimst.one/aw/wombat/generate"
)

const dateformat string = "2006-01-02"
const stub string = `---
title: "{{.Title}}"
date: {{.Date}}
categories: 
---

`

type post struct {
	Title string
	Date  string
}

func filename(dirsuffix string, title string, now time.Time) string {
	date := now.Format(dateformat)
	asciiTitle := blog.ConvASCII(title)
	return filepath.Join("stage0", "blog"+dirsuffix, fmt.Sprintf("%s-%s.md", date, asciiTitle))
}

func ensureDirectory(file string) {
	dir := filepath.Dir(file)
	err := os.MkdirAll(dir, 0755)
	if err != nil {
		panic(err)
	}
}

func makePostFile(now time.Time, dirsuffix string, title string, content string) string {
	file := filename(dirsuffix, title, now)
	ensureDirectory(file)
	post := post{}
	post.Title = title
	post.Date = now.Format(blog.TimeFormat)
	t := template.Must(template.New("Poststub").Parse(stub))
	buf := new(bytes.Buffer)
	t.Execute(buf, post)
	err := goutil.WriteFile(file, buf.String()+content)
	if err != nil {
		fmt.Println(err)
	}
	return file
}

func postNew(fl postFlags) error {
	var err error
	if fl.title == "" {
		fl.title, err = goutil.AskFor("Title")
		if err != nil {
			return err
		}
	}
	var content string
	if fl.category != "" && fl.title != "" {
		tmpcontent, _ := ioutil.ReadAll(os.Stdin)
		content = string(tmpcontent)
	}
	var t time.Time
	if fl.datetime.val != nil {
		t = *fl.datetime.val
	} else {
		t = time.Now().UTC()
	}
	f := makePostFile(t, fl.blog, fl.title, content)
	fmt.Println(f)
	if content == "" {
		wait := true
		err = goutil.OpenInEditor(f, wait)
		if err != nil {
			fmt.Println(err)
			fmt.Println("trying default application...")
			err = goutil.OpenInDefaultApp(f, wait)
		}
	}
	if err != nil {
		return err
	}
	return gen.Generate(gen.GenerateFlags{Noserve: fl.noserve})
}

type DateFlag struct {
	val *time.Time
}

func (d DateFlag) String() string {
	if d.val == nil {
		return ""
	} else {
		return time.Time(*d.val).Format(blog.TimeFormat)
	}
}

func (d *DateFlag) Set(s string) error {
	if d == nil {
		return errors.New("func (d *DateFlag) Set(s string): d is nil")
	}
	val, err := time.Parse(blog.TimeFormat, s)
	if err == nil {
		d.val = &val
	}
	return err
}

type postFlags struct {
	blog     string
	title    string
	category string
	noserve  bool
	datetime DateFlag
}

func Command() (goutil.CommandFlagsInit, goutil.CommandFunc) {
	f := postFlags{}
	flagsInit := func(s *flag.FlagSet) {
		s.StringVar(&f.blog, "blog", "", "which blog folder to post to, e.g. -blog=foo for 'blogfoo' (default \"blog\")")
		s.StringVar(&f.title, "title", "", "if title and category are set: read content from stdin")
		s.StringVar(&f.category, "category", "", "if title and category are set: read content from stdin")
		s.BoolVar(&f.noserve, "noserve", false, "don't generate and serve afterwards")
		s.Var(&f.datetime, "date", "use date and time other than now (yyyy-mm-dd HH:MM)")
	}
	return flagsInit, func([]string) error { return postNew(f) }
}