import { ToolConfig } from '../types'
import { GoogleDocsToolParams, GoogleDocsWriteResponse } from './types'

export const writeTool: ToolConfig<GoogleDocsToolParams, GoogleDocsWriteResponse> = {
  id: 'google_docs_write',
  name: 'Write to Google Docs Document',
  description: 'Write or update content in a Google Docs document',
  version: '1.0',
  oauth: {
    required: true,
    provider: 'google-docs',
    additionalScopes: [
      'https://www.googleapis.com/auth/documents',
      'https://www.googleapis.com/auth/drive',
    ],
  },
  params: {
    accessToken: { type: 'string', required: true },
    documentId: { type: 'string', required: true },
    content: { type: 'string', required: true },
  },
  request: {
    url: (params) => {
      // Ensure documentId is valid
      const documentId = params.documentId?.trim()
      if (!documentId) {
        throw new Error('Document ID is required')
      }

      return `https://docs.googleapis.com/v1/documents/${documentId}:batchUpdate`
    },
    method: 'POST',
    headers: (params) => {
      // Validate access token
      if (!params.accessToken) {
        throw new Error('Access token is required')
      }

      return {
        Authorization: `Bearer ${params.accessToken}`,
        'Content-Type': 'application/json',
      }
    },
    body: (params) => {
      // Validate content
      if (!params.content) {
        throw new Error('Content is required')
      }

      // Following the exact format from the Google Docs API examples
      // Always insert at the end of the document to avoid duplication
      // See: https://developers.google.com/docs/api/reference/rest/v1/documents/request#InsertTextRequest
      const requestBody = {
        requests: [
          {
            insertText: {
              endOfSegmentLocation: {},
              text: params.content,
            },
          },
        ],
      }

      return requestBody
    },
  },
  transformResponse: async (response: Response) => {
    if (!response.ok) {
      let errorText = ''
      try {
        const responseClone = response.clone()
        const responseText = await responseClone.text()
        errorText = responseText
      } catch (e) {
        errorText = 'Unable to read error response'
      }

      throw new Error(`Failed to write to Google Docs document (${response.status}): ${errorText}`)
    }

    try {
      const responseText = await response.text()

      // Parse the response if it's not empty
      let data = {}
      if (responseText.trim()) {
        data = JSON.parse(responseText)
      }

      // Get the document ID from the URL
      const urlParts = response.url.split('/')
      let documentId = ''
      for (let i = 0; i < urlParts.length; i++) {
        if (urlParts[i] === 'documents' && i + 1 < urlParts.length) {
          documentId = urlParts[i + 1].split(':')[0]
          break
        }
      }

      // Create document metadata
      const metadata = {
        documentId,
        title: 'Updated Document',
        mimeType: 'application/vnd.google-apps.document',
        url: `https://docs.google.com/document/d/${documentId}/edit`,
      }

      return {
        success: true,
        output: {
          updatedContent: true,
          metadata,
        },
      }
    } catch (error) {
      throw error
    }
  },
  transformError: (error) => {
    // If it's an Error instance with a message, use that
    if (error instanceof Error) {
      return error.message
    }

    // If it's an object with an error or message property
    if (typeof error === 'object' && error !== null) {
      if (error.error) {
        return typeof error.error === 'string' ? error.error : JSON.stringify(error.error)
      }
      if (error.message) {
        return error.message
      }
    }

    // Default fallback message
    return 'An error occurred while writing to Google Docs'
  },
}