xref: /plugin/aichat/helper.php (revision 9e81bea79e153f16a1470ded51bcd0395dfad8cc) 
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
77        if ($similar) {
78            $context = implode("\n", array_column($similar, 'text'));
79            $prompt = $this->getPrompt('question', ['context' => $context]);
80        } else {
81            $prompt = $this->getPrompt('noanswer');
82        }
83        $messages = [
84            [
85                'role' => 'system',
86                'content' => $prompt
87            ],
88            [
89                'role' => 'user',
90                'content' => $question
91            ]
92        ];
93
94        $answer = $this->openAI->getChatAnswer($messages);
95
96        return [
97            'question' => $question,
98            'answer' => $answer,
99            'sources' => $similar,
100        ];
101    }
102
103    /**
104     * Rephrase a question into a standalone question based on the chat history
105     *
106     * @param string $question The original user question
107     * @param array[] $history The chat history [[user, ai], [user, ai], ...]
108     * @return string The rephrased question
109     * @throws Exception
110     */
111    public function rephraseChatQuestion($question, $history)
112    {
113        // go back in history as far as possible without hitting the token limit
114        $tiktok = new Encoder();
115        $chatHistory = '';
116        $history = array_reverse($history);
117        foreach ($history as $row) {
118            if (count($tiktok->encode($chatHistory)) > 3000) {
119                break;
120            }
121
122            $chatHistory =
123                "Human: " . $row[0] . "\n" .
124                "Assistant: " . $row[1] . "\n" .
125                $chatHistory;
126        }
127
128        // ask openAI to rephrase the question
129        $prompt = $this->getPrompt('rephrase', ['history' => $chatHistory, 'question' => $question]);
130        $messages = [['role' => 'user', 'content' => $prompt]];
131        return $this->openAI->getChatAnswer($messages);
132    }
133
134    /**
135     * Load the given prompt template and fill in the variables
136     *
137     * @param string $type
138     * @param string[] $vars
139     * @return string
140     */
141    protected function getPrompt($type, $vars = [])
142    {
143        $template = file_get_contents($this->localFN('prompt_' . $type));
144
145        $replace = array();
146        foreach ($vars as $key => $val) {
147            $replace['{{' . strtoupper($key) . '}}'] = $val;
148        }
149
150        return strtr($template, $replace);
151    }
152}
153
154