feat: Add support for Google Gemini

src/providers/google/api.ts

@@ -0,0 +1,15 @@
+export interface GoogleFetchPayload {
+  apiKey: string
+  body: Record<string, any>
+  model?: string
+}
+
+export const fetchChatCompletion = async(payload: GoogleFetchPayload) => {
+  const { apiKey, body, model } = payload || {}
+  const initOptions = {
+    headers: { 'Content-Type': 'application/json' },
+    method: 'POST',
+    body: JSON.stringify({ ...body }),
+  }
+  return fetch(`https://generativelanguage.googleapis.com/v1/models/${model}:generateContent?key=${apiKey}`, initOptions)
+}

src/providers/google/handler.ts

@@ -0,0 +1,71 @@
+import { fetchChatCompletion } from './api'
+import { parseMessageList } from './parser'
+import type { Message } from '@/types/message'
+import type { HandlerPayload, Provider } from '@/types/provider'
+
+export const handlePrompt: Provider['handlePrompt'] = async(payload, signal?: AbortSignal) => {
+  if (payload.botId === 'chat_continuous')
+    return handleChatCompletion(payload, signal)
+  if (payload.botId === 'chat_single')
+    return handleChatCompletion(payload, signal)
+}
+
+export const handleRapidPrompt: Provider['handleRapidPrompt'] = async(prompt, globalSettings) => {
+  const rapidPromptPayload = {
+    conversationId: 'temp',
+    conversationType: 'chat_single',
+    botId: 'temp',
+    globalSettings: {
+      ...globalSettings,
+      model: 'gemini-pro',
+    },
+    botSettings: {},
+    prompt,
+    messages: { contents: [{ role: 'user', parts: [{ text: prompt }] }] },
+  } as unknown as HandlerPayload
+  const result = await handleChatCompletion(rapidPromptPayload)
+  if (typeof result === 'string')
+    return result
+  return ''
+}
+
+export const handleChatCompletion = async(payload: HandlerPayload, signal?: AbortSignal) => {
+  // An array to store the chat messages
+  const messages: Message[] = []
+
+  let maxTokens = payload.globalSettings.maxTokens as number
+  let messageHistorySize = payload.globalSettings.messageHistorySize as number
+
+  // Iterate through the message history
+  while (messageHistorySize > 0) {
+    messageHistorySize--
+    // Get the last message from the payload
+    const m = payload.messages.pop()
+    if (m === undefined)
+      break
+
+    if (maxTokens - m.content.length < 0)
+      break
+
+    maxTokens -= m.content.length
+    messages.unshift(m)
+  }
+
+  const response = await fetchChatCompletion({
+    apiKey: payload.globalSettings.apiKey as string,
+    body: {
+      contents: parseMessageList(messages),
+    },
+    model: payload.globalSettings.model as string,
+  })
+
+  if (response.ok) {
+    const json = await response.json()
+    // console.log('json', json)
+    const output = json.candidates[0].content.parts[0].text || json
+    return output as string
+  }
+
+  const text = await response.text()
+  throw new Error(`Failed to fetch chat completion: ${text}`)
+}

src/providers/google/index.ts

@@ -0,0 +1,70 @@
+import {
+  handlePrompt,
+  handleRapidPrompt,
+} from './handler'
+import type { Provider } from '@/types/provider'
+
+const providerGoogle = () => {
+  const provider: Provider = {
+    id: 'provider-google',
+    icon: 'i-simple-icons-google', // @unocss-include
+    name: 'Google',
+    globalSettings: [
+      {
+        key: 'apiKey',
+        name: 'API Key',
+        type: 'api-key',
+      },
+      {
+        key: 'model',
+        name: 'Google model',
+        description: 'Custom model for Google API.',
+        type: 'select',
+        options: [
+          { value: 'gemini-pro', label: 'gemini-pro' },
+        ],
+        default: 'gemini-pro',
+      },
+      {
+        key: 'maxTokens',
+        name: 'Max Tokens',
+        description: 'The maximum number of tokens to generate in the completion.',
+        type: 'slider',
+        min: 0,
+        max: 32768,
+        default: 2048,
+        step: 1,
+      },
+      {
+        key: 'messageHistorySize',
+        name: 'Max History Message Size',
+        description: 'The number of retained historical messages will be truncated if the length of the message exceeds the MaxToken parameter.',
+        type: 'slider',
+        min: 1,
+        max: 24,
+        default: 5,
+        step: 1,
+      },
+    ],
+    bots: [
+      {
+        id: 'chat_continuous',
+        type: 'chat_continuous',
+        name: 'Continuous Chat',
+        settings: [],
+      },
+      {
+        id: 'chat_single',
+        type: 'chat_single',
+        name: 'Single Chat',
+        settings: [],
+      },
+
+    ],
+    handlePrompt,
+    handleRapidPrompt,
+  }
+  return provider
+}
+
+export default providerGoogle

src/providers/google/parser.ts

@@ -0,0 +1,35 @@
+import type { Message } from '@/types/message'
+
+export const parseMessageList = (rawList: Message[]) => {
+  interface GoogleGeminiMessage {
+    role: 'user' | 'model'
+    // TODO: Add support for image input
+    parts: [
+      { text: string },
+    ]
+  }
+
+  if (rawList.length === 0)
+    return []
+
+  const parsedList: GoogleGeminiMessage[] = []
+  // if first message is system message, insert an empty message after it
+  if (rawList[0].role === 'system') {
+    parsedList.push({ role: 'user', parts: [{ text: rawList[0].content }] })
+    parsedList.push({ role: 'model', parts: [{ text: 'OK.' }] })
+  }
+  // covert other messages
+  const roleDict = {
+    user: 'user',
+    assistant: 'model',
+  } as const
+  for (const message of rawList) {
+    if (message.role === 'system')
+      continue
+    parsedList.push({
+      role: roleDict[message.role],
+      parts: [{ text: message.content }],
+    })
+  }
+  return parsedList
+}

src/stores/provider.ts

@@ -1,5 +1,6 @@
 import providerOpenAI from '@/providers/openai'
 import providerAzure from '@/providers/azure'
+import providerGoogle from '@/providers/google'
 import providerReplicate from '@/providers/replicate'
 import { allConversationTypes } from '@/types/conversation'
 import type { BotMeta } from '@/types/app'
@@ -8,6 +9,7 @@ export const providerList = [
   providerOpenAI(),
   providerAzure(),
   providerReplicate(),
+  providerGoogle(),
 ]
 
 export const providerMetaList = providerList.map(provider => ({