1// SPDX-FileCopyrightText: 2022 Amolith <amolith@secluded.site>
2//
3// SPDX-License-Identifier: BSD-2-Clause
4
5package main
6
7import (
8 "errors"
9 "fmt"
10 "log"
11 "strings"
12 "text/template"
13
14 "github.com/dgraph-io/badger/v3"
15)
16
17// Create shortens a given URL with an optional name. If a name is provided,
18// that name will be used. Otherwise, 4-character string will be generated and
19// used instead.
20func (m model) create(name string, url string) string {
21 err := m.database.Update(func(txn *badger.Txn) error {
22 return txn.Set([]byte(name), []byte(url))
23 })
24 if err != nil {
25 return fmt.Sprint(err)
26 }
27
28 log.Println("\"" + url + "\" mapped to \"" + name + "\"")
29 return fmt.Sprint("URL mapped to ", name, "\n")
30}
31
32// read() accepts a start variable for the first link in a set (implying reverse
33// iteration), an end variable for the last link in a set (implying forward
34// iteration), and a count variable for the number of requested entries. The
35// requested set is returned as JSON.
36func (m model) read(start string, end string, count int) (map[string]string, error) {
37 links := make(map[string]string)
38
39 if !(count > 0) {
40 return nil, errors.New("Count parameter is required")
41 }
42
43 err := m.database.View(func(txn *badger.Txn) error {
44 opts := badger.DefaultIteratorOptions
45 opts.PrefetchSize = 10
46 if start != "" && end == "" {
47 opts.Reverse = true
48 }
49 iterator := txn.NewIterator(opts)
50 if start != "" && end == "" {
51 iterator.Seek([]byte(end))
52 } else if start == "" && end != "" {
53 iterator.Seek([]byte(start))
54 }
55 defer iterator.Close()
56 for iterator.Rewind(); iterator.Valid(); iterator.Next() {
57 err := iterator.Item().Value(func(v []byte) error {
58 links[string(iterator.Item().Key())] = string(v)
59 return nil
60 })
61 if err != nil {
62 return err
63 }
64 }
65 return nil
66 })
67 if err != nil {
68 return nil, err
69 }
70
71 return links, nil
72}
73
74// Update modifies a shortened link
75func (m model) update(name string, url string, oldName string) string {
76 m.create(name, url)
77 if name != oldName {
78 m.delete(oldName)
79 }
80 return fmt.Sprint("\"" + url + "\" mapped to \"" + name + "\"")
81}
82
83// Delete removes a shortened URL from the database given its name.
84func (m model) delete(name string) string {
85 err := m.database.Update(func(txn *badger.Txn) error {
86 return txn.Delete([]byte(name))
87 })
88 if err != nil {
89 return fmt.Sprint(err)
90 }
91
92 log.Println("\"" + name + "\" has been deleted")
93 return fmt.Sprint("\"" + name + "\" has been deleted\n")
94}
95
96// nameExists returns true if the provided name is already stored in the
97// database and false if it's not.
98func (m model) nameExists(name string) bool {
99 err := m.database.View(func(txn *badger.Txn) error {
100 _, err := txn.Get([]byte(name))
101 if err != nil {
102 return err
103 }
104 return nil
105 })
106 return err == nil
107}
108
109// unauthenticated serves the unauthenticated home page to the visitor
110func unauthenticated() string {
111 home, err := templates.ReadFile("templates/home_unauthenticated.html")
112 if err != nil {
113 log.Fatalln(err)
114 }
115 return string(home)
116}
117
118// authenticated serves the authenticated dashboard to the user
119func (m model) authenticated() string {
120 dash, err := templates.ReadFile("templates/home_authenticated.html")
121 if err != nil {
122 log.Fatalln(err)
123 }
124 tmpl, err := template.New("authenticated").Parse(string(dash))
125 if err != nil {
126 log.Println(err)
127 }
128 page := new(strings.Builder)
129 err = tmpl.Execute(page, m.genTable())
130 if err != nil {
131 log.Println(err)
132 }
133 return page.String()
134}
135
136type EditFields struct {
137 URL string
138 Name string
139}
140
141// update serves the editing interface to the user
142func (m model) edit(name string, url string) string {
143 fields := EditFields{url, name}
144 editPage, err := templates.ReadFile("templates/edit.html")
145 if err != nil {
146 log.Fatalln(err)
147 }
148 tmpl, err := template.New("editPage").Parse(string(editPage))
149 if err != nil {
150 log.Println(err)
151 }
152 page := new(strings.Builder)
153 err = tmpl.Execute(page, fields)
154 if err != nil {
155 log.Println(err)
156 }
157 return page.String()
158}