xref: /plugin/aichat/helper.php (revision 0337f47f2dd6cc31bdbfd81a2499e687ce633b47)
1<?php
2
3use dokuwiki\plugin\aichat\Embeddings;
4use dokuwiki\plugin\aichat\OpenAI;
5use TikToken\Encoder;
6
7require_once __DIR__ . '/vendor/autoload.php';
8
9/**
10 * DokuWiki Plugin aichat (Helper Component)
11 *
12 * @license GPL 2 http://www.gnu.org/licenses/gpl-2.0.html
13 * @author  Andreas Gohr <gohr@cosmocode.de>
14 */
15class helper_plugin_aichat extends \dokuwiki\Extension\Plugin
16{
17    /** @var OpenAI */
18    protected $openAI;
19    /** @var Embeddings */
20    protected $embeddings;
21
22    public function __construct()
23    {
24        $this->openAI = new OpenAI($this->getConf('openaikey'), $this->getConf('openaiorg'));
25        $this->embeddings = new Embeddings($this->openAI);
26    }
27
28    /**
29     * Access the OpenAI client
30     *
31     * @return OpenAI
32     */
33    public function getOpenAI()
34    {
35        return $this->openAI;
36    }
37
38    /**
39     * Access the Embeddings interface
40     *
41     * @return Embeddings
42     */
43    public function getEmbeddings()
44    {
45        return $this->embeddings;
46    }
47
48    /**
49     * Ask a question with a chat history
50     *
51     * @param string $question
52     * @param array[] $history The chat history [[user, ai], [user, ai], ...]
53     * @return array ['question' => $question, 'answer' => $answer, 'sources' => $sources]
54     * @throws Exception
55     */
56    public function askChatQuestion($question, $history = [])
57    {
58        if ($history) {
59            $standaloneQuestion = $this->rephraseChatQuestion($question, $history);
60        } else {
61            $standaloneQuestion = $question;
62        }
63        return $this->askQuestion($standaloneQuestion);
64    }
65
66    /**
67     * Ask a single standalone question
68     *
69     * @param string $question
70     * @return array ['question' => $question, 'answer' => $answer, 'sources' => $sources]
71     * @throws Exception
72     */
73    public function askQuestion($question)
74    {
75        $similar = $this->embeddings->getSimilarChunks($question);
76        $context = implode("\n", array_column($similar, 'text'));
77
78        $prompt = $this->getPrompt('question', ['context' => $context]);
79        $messages = [
80            [
81                'role' => 'system',
82                'content' => $prompt
83            ],
84            [
85                'role' => 'user',
86                'content' => $question
87            ]
88        ];
89
90        $answer = $this->openAI->getChatAnswer($messages);
91
92        return [
93            'question' => $question,
94            'answer' => $answer,
95            'sources' => $similar,
96        ];
97    }
98
99    /**
100     * Rephrase a question into a standalone question based on the chat history
101     *
102     * @param string $question The original user question
103     * @param array[] $history The chat history [[user, ai], [user, ai], ...]
104     * @return string The rephrased question
105     * @throws Exception
106     */
107    public function rephraseChatQuestion($question, $history)
108    {
109        // go back in history as far as possible without hitting the token limit
110        $tiktok = new Encoder();
111        $chatHistory = '';
112        $history = array_reverse($history);
113        foreach ($history as $row) {
114            if (count($tiktok->encode($chatHistory)) > 3000) {
115                break;
116            }
117
118            $chatHistory =
119                "Human: " . $row[0] . "\n" .
120                "Assistant: " . $row[1] . "\n" .
121                $chatHistory;
122        }
123
124        // ask openAI to rephrase the question
125        $prompt = $this->getPrompt('rephrase', ['history' => $chatHistory, 'question' => $question]);
126        $messages = [['role' => 'user', 'content' => $prompt]];
127        return $this->openAI->getChatAnswer($messages);
128    }
129
130    /**
131     * Load the given prompt template and fill in the variables
132     *
133     * @param string $type
134     * @param string[] $vars
135     * @return string
136     */
137    protected function getPrompt($type, $vars = [])
138    {
139        $template = file_get_contents($this->localFN('prompt_' . $type));
140
141        $replace = array();
142        foreach ($vars as $key => $val) {
143            $replace['{{' . strtoupper($key) . '}}'] = $val;
144        }
145
146        return strtr($template, $replace);
147    }
148}
149
150