package db

import (
	"bytes"
	"git.giftfish.de/ston1th/gowiki/pkg/render"
	"github.com/boltdb/bolt"
	"html/template"
	"strings"
)

type Snippet struct {
	Title      string        `json:"title"`
	LinkTitle  string        `json:"-"`
	Index      template.HTML `json:"index"`
	Text       template.HTML `json:"text"`
	MD         string        `json:"md"`
	Created    string        `json:"created"`
	Updated    string        `json:"updated"`
	Permission int           `json:"permission"`
}

func copyBuf(buf []byte) (b []byte) {
	b = make([]byte, len(buf))
	copy(b, buf)
	return
}

var (
	errSnippetNotExists = dbErr("snippet does not exist")
	errSnippetExists    = dbErr("snippet already exist")
)

func (bs *BoltStore) GetSnippets(username string) (snip []Snippet, err error) {
	user := []byte(username)
	var buf [][]byte
	err = bs.db.View(func(tx *bolt.Tx) error {
		return tx.Bucket([]byte(snippetTable)).ForEach(func(k, v []byte) error {
			if !bytes.HasPrefix(k, user) {
				return nil
			}
			buf = append(buf, copyBuf(v))
			return nil
		})
	})
	if err != nil {
		return
	}
	for _, b := range buf {
		s := new(Snippet)
		if err = bs.Unmarshal(b, s); err != nil {
			return
		}
		snip = append(snip, *s)
	}
	return
}

func (bs *BoltStore) GetSnippet(username, title string, perm int) (*Snippet, error) {
	s := new(Snippet)
	err := bs.db.View(func(tx *bolt.Tx) error {
		v := tx.Bucket([]byte(snippetTable)).Get([]byte(title))
		if v == nil {
			return errSnippetNotExists
		}
		return bs.Unmarshal(v, s)
	})
	if err != nil {
		return nil, err
	}
	switch s.Permission {
	case 0:
		return s, nil
	case 1:
		if username != "" {
			return s, nil
		}
	case 2:
		if strings.HasPrefix(title, username) {
			return s, nil
		}
	}
	return nil, errSnippetNotExists
}

func (bs *BoltStore) snippetExists(username, title string, perm int) (err error) {
	_, err = bs.GetSnippet(username, title, perm)
	return
}

func makeKey(username, title string) string {
	return username + title
}

func checkPerm(p int) error {
	switch p {
	case 0, 1, 2:
		return nil
	}
	return errInvalidPermission
}

func (bs *BoltStore) CreateSnippet(username, title, text string, perm int) (newTitle string, err error) {
	//newTitle, title = makeLinkTitle(title)
	err = checkPerm(perm)
	if err != nil {
		return
	}
	err = bs.snippetExists(username, title, perm)
	if err == nil {
		err = errSnippetExists
		return
	}
	err = bs.db.Update(func(tx *bolt.Tx) error {
		snip := render.Render(text).Snippet()
		snip.Title = title
		snip.Created = username + " " + now()
		snip.Permission = perm
		v, err := bs.Marshal(snip)
		if err != nil {
			return err
		}
		return tx.Bucket([]byte(snippetTable)).Put([]byte(makeKey(username, title)), v)
	})
	return
}

func (bs *BoltStore) EditSnippet(username, title, text string, perm int) (err error) {
	err = checkPerm(perm)
	if err != nil {
		return
	}
	err = bs.snippetExists(username, title, perm)
	if err != nil {
		return
	}
	err = bs.db.Update(func(tx *bolt.Tx) error {
		snip := render.Render(text).Snippet()
		snip.Title = title
		snip.Created = username + " " + now()
		snip.Permission = perm
		v, err := bs.Marshal(snip)
		if err != nil {
			return err
		}
		return tx.Bucket([]byte(snippetTable)).Put([]byte(makeKey(username, title)), v)
	})
	return
}