add ollama support (#269)

* add ollama support

---------

Co-authored-by: di-sukharev <dim.sukharev@gmail.com>
Co-authored-by: GPT10 <57486732+di-sukharev@users.noreply.github.com>
Co-authored-by: Jaroslaw Weber <jaroslaw.weber@adriel.com>

src/engine/openAi.ts

@@ -0,0 +1,109 @@
+import axios from 'axios';
+import chalk from 'chalk';
+import { execa } from 'execa';
+import {
+  ChatCompletionRequestMessage,
+  Configuration as OpenAiApiConfiguration,
+  OpenAIApi
+} from 'openai';
+
+import { intro, outro } from '@clack/prompts';
+
+import {
+  CONFIG_MODES,
+  DEFAULT_MODEL_TOKEN_LIMIT,
+  getConfig
+} from '../commands/config';
+import { GenerateCommitMessageErrorEnum } from '../generateCommitMessageFromGitDiff';
+import { tokenCount } from '../utils/tokenCount';
+import { AiEngine } from './Engine';
+
+const config = getConfig();
+
+let maxTokens = config?.OCO_OPENAI_MAX_TOKENS;
+let basePath = config?.OCO_OPENAI_BASE_PATH;
+let apiKey = config?.OCO_OPENAI_API_KEY
+
+const [command, mode] = process.argv.slice(2);
+
+const isLocalModel = config?.OCO_AI_PROVIDER == 'ollama'
+
+
+if (!apiKey && command !== 'config' && mode !== CONFIG_MODES.set && !isLocalModel) {
+  intro('opencommit');
+
+  outro(
+    'OCO_OPENAI_API_KEY is not set, please run `oco config set OCO_OPENAI_API_KEY=<your token> . If you are using GPT, make sure you add payment details, so API works.`'
+  );
+  outro(
+    'For help look into README https://github.com/di-sukharev/opencommit#setup'
+  );
+
+  process.exit(1);
+}
+
+const MODEL = config?.OCO_MODEL || 'gpt-3.5-turbo';
+
+class OpenAi implements AiEngine {
+  private openAiApiConfiguration = new OpenAiApiConfiguration({
+    apiKey: apiKey
+  });
+  private openAI!: OpenAIApi;
+
+  constructor() {
+    if (basePath) {
+      this.openAiApiConfiguration.basePath = basePath;
+    }
+    this.openAI = new OpenAIApi(this.openAiApiConfiguration);
+  }
+
+  public generateCommitMessage = async (
+    messages: Array<ChatCompletionRequestMessage>
+  ): Promise<string | undefined> => {
+    const params = {
+      model: MODEL,
+      messages,
+      temperature: 0,
+      top_p: 0.1,
+      max_tokens: maxTokens || 500
+    };
+    try {
+      const REQUEST_TOKENS = messages
+        .map((msg) => tokenCount(msg.content) + 4)
+        .reduce((a, b) => a + b, 0);
+
+      if (REQUEST_TOKENS > DEFAULT_MODEL_TOKEN_LIMIT - maxTokens) {
+        throw new Error(GenerateCommitMessageErrorEnum.tooMuchTokens);
+      }
+
+      const { data } = await this.openAI.createChatCompletion(params);
+
+      const message = data.choices[0].message;
+
+      return message?.content;
+    } catch (error) {
+      outro(`${chalk.red('✖')} ${JSON.stringify(params)}`);
+
+      const err = error as Error;
+      outro(`${chalk.red('✖')} ${err?.message || err}`);
+
+      if (
+        axios.isAxiosError<{ error?: { message: string } }>(error) &&
+        error.response?.status === 401
+      ) {
+        const openAiError = error.response.data.error;
+
+        if (openAiError?.message) outro(openAiError.message);
+        outro(
+          'For help look into README https://github.com/di-sukharev/opencommit#setup'
+        );
+      }
+
+      throw err;
+    }
+  };
+}
+
+
+
+export const api = new OpenAi();