package main

import (
	"errors"
	"fmt"
	"math/rand"
	"net/url"
	"strings"
	"time"
)

type Entry struct {
	Content    string
	Name       string
	Categories []string
	Slug       string
	Summary    string
	InReplyTo  string
	LikeOf     string
	RepostOf   string
	section    string
	location   string
	filename   string
	token      string
}

func CreateEntry(contentType ContentType, body string) (*Entry, error) {
	if contentType == WwwForm {
		bodyValues, err := url.ParseQuery(body)
		if err != nil {
			return nil, errors.New("failed to parse query")
		}
		return createEntryFromURLValues(bodyValues)
	} else if contentType == Json || contentType == Multipart {
		return nil, errors.New("multipart and json content-type are not implemented yet")
	} else {
		return nil, errors.New("unsupported content-type")
	}
}

func createEntryFromURLValues(bodyValues url.Values) (*Entry, error) {
	if h, ok := bodyValues["h"]; ok && len(h) == 1 && h[0] != "entry" {
		return nil, errors.New("only entry type is supported so far")
	}
	if _, ok := bodyValues["content"]; ok {
		entry := new(Entry)
		entry.Content = bodyValues["content"][0]
		if name, ok := bodyValues["name"]; ok {
			entry.Name = name[0]
		}
		if category, ok := bodyValues["category"]; ok {
			entry.Categories = category
		} else if categories, ok := bodyValues["category[]"]; ok {
			entry.Categories = categories
		} else {
			entry.Categories = nil
		}
		if slug, ok := bodyValues["mp-slug"]; ok && len(slug) > 0 && slug[0] != "" {
			entry.Slug = slug[0]
		}
		if summary, ok := bodyValues["summary"]; ok {
			entry.Summary = summary[0]
		}
		if inReplyTo, ok := bodyValues["in-reply-to"]; ok {
			entry.InReplyTo = inReplyTo[0]
		}
		if likeOf, ok := bodyValues["like-of"]; ok {
			entry.LikeOf = likeOf[0]
		}
		if repostOf, ok := bodyValues["repost-of"]; ok {
			entry.RepostOf = repostOf[0]
		}
		if token, ok := bodyValues["access_token"]; ok {
			entry.token = "Bearer " + token[0]
		}
		err := computeExtraSettings(entry)
		if err != nil {
			return nil, err
		}
		return entry, nil
	}
	return nil, errors.New("error parsing the entry from URL Values")
}

func computeExtraSettings(entry *Entry) error {
	now := time.Now()
	entry.section = "micro"
	// Find settings hidden in category strings
	filteredCategories := make([]string, 0)
	for _, category := range entry.Categories {
		if strings.HasPrefix(category, "section-") {
			entry.section = strings.TrimPrefix(category, "section-")
		} else if strings.HasPrefix(category, "slug-") {
			entry.Slug = strings.TrimPrefix(category, "slug-")
		} else {
			filteredCategories = append(filteredCategories, category)
		}
	}
	entry.Categories = filteredCategories
	// Compute slug if empty
	if len(entry.Slug) == 0 || entry.Slug == "" {
		random := generateRandomString(now, 5)
		entry.Slug = fmt.Sprintf("%v-%02d-%02d-%v", now.Year(), int(now.Month()), now.Day(), random)
	}
	// Compute filename and location
	blogURL, err := GetBlogURL()
	if err != nil {
		return err
	}
	if entry.section == "posts" {
		entry.filename = "content/" + entry.section + "/" + entry.Slug + ".md"
		entry.location = blogURL + entry.section + "/" + entry.Slug
	} else if entry.section == "thoughts" || entry.section == "links" {
		entry.filename = fmt.Sprintf("content/%v/%02d/%02d/%v.md", entry.section, now.Year(), int(now.Month()), entry.Slug)
		entry.location = fmt.Sprintf("%v%v/%02d/%02d/%v", blogURL, entry.section, now.Year(), int(now.Month()), entry.Slug)
	} else {
		entry.filename = "content/" + entry.section + "/" + entry.Slug + ".md"
		entry.location = blogURL + entry.section + "/" + entry.Slug
	}
	return nil
}

func generateRandomString(now time.Time, n int) string {
	rand.Seed(now.UnixNano())
	letters := []rune("abcdefghijklmnopqrstuvwxyz")
	b := make([]rune, n)
	for i := range b {
		b[i] = letters[rand.Intn(len(letters))]
	}
	return string(b)
}

func WriteEntry(entry *Entry) (string, error) {
	file := WriteHugoPost(entry)
	err := CommitEntry(entry.filename, file, entry.Name)
	if err != nil {
		return "", err
	}
	return entry.location, nil
}