import { omit } from 'lodash'
import { ICommonObject, IDocument, INode, INodeData, INodeParams, INodeOptionsValue } from '../../../src/Interface'
import { TextSplitter } from 'langchain/text_splitter'
import {
    convertMultiOptionsToStringArray,
    getCredentialData,
    getCredentialParam,
    handleEscapeCharacters,
    INodeOutputsValue,
    refreshOAuth2Token
} from '../../../src'

class GoogleSheets_DocumentLoaders implements INode {
    label: string
    name: string
    version: number
    description: string
    type: string
    icon: string
    category: string
    baseClasses: string[]
    credential: INodeParams
    inputs: INodeParams[]
    outputs: INodeOutputsValue[]

    constructor() {
        this.label = 'Google Sheets'
        this.name = 'googleSheets'
        this.version = 1.0
        this.type = 'Document'
        this.icon = 'google-sheets.svg'
        this.category = 'Document Loaders'
        this.description = `Load data from Google Sheets as documents`
        this.baseClasses = [this.type]
        this.credential = {
            label: 'Connect Credential',
            name: 'credential',
            type: 'credential',
            description: 'Google Sheets OAuth2 Credential',
            credentialNames: ['googleSheetsOAuth2']
        }
        this.inputs = [
            {
                label: 'Select Spreadsheet',
                name: 'spreadsheetIds',
                type: 'asyncMultiOptions',
                loadMethod: 'listSpreadsheets',
                description: 'Select spreadsheet from your Google Drive',
                refresh: true
            },
            {
                label: 'Sheet Names',
                name: 'sheetNames',
                type: 'string',
                description: 'Comma-separated list of sheet names to load. If empty, loads all sheets.',
                placeholder: 'Sheet1, Sheet2',
                optional: true
            },
            {
                label: 'Range',
                name: 'range',
                type: 'string',
                description: 'Range to load (e.g., A1:E10). If empty, loads entire sheet.',
                placeholder: 'A1:E10',
                optional: true
            },
            {
                label: 'Include Headers',
                name: 'includeHeaders',
                type: 'boolean',
                description: 'Whether to include the first row as headers',
                default: true
            },
            {
                label: 'Value Render Option',
                name: 'valueRenderOption',
                type: 'options',
                description: 'How values should be represented in the output',
                options: [
                    {
                        label: 'Formatted Value',
                        name: 'FORMATTED_VALUE'
                    },
                    {
                        label: 'Unformatted Value',
                        name: 'UNFORMATTED_VALUE'
                    },
                    {
                        label: 'Formula',
                        name: 'FORMULA'
                    }
                ],
                default: 'FORMATTED_VALUE',
                optional: true
            },
            {
                label: 'Text Splitter',
                name: 'textSplitter',
                type: 'TextSplitter',
                optional: true
            },
            {
                label: 'Additional Metadata',
                name: 'metadata',
                type: 'json',
                description: 'Additional metadata to be added to the extracted documents',
                optional: true,
                additionalParams: true
            },
            {
                label: 'Omit Metadata Keys',
                name: 'omitMetadataKeys',
                type: 'string',
                rows: 4,
                description:
                    'Each document loader comes with a default set of metadata keys that are extracted from the document. You can use this field to omit some of the default metadata keys. The value should be a list of keys, seperated by comma. Use * to omit all metadata keys execept the ones you specify in the Additional Metadata field',
                placeholder: 'key1, key2, key3.nestedKey1',
                optional: true,
                additionalParams: true
            }
        ]
        this.outputs = [
            {
                label: 'Document',
                name: 'document',
                description: 'Array of document objects containing metadata and pageContent',
                baseClasses: [...this.baseClasses, 'json']
            },
            {
                label: 'Text',
                name: 'text',
                description: 'Concatenated string from pageContent of documents',
                baseClasses: ['string', 'json']
            }
        ]
    }

    //@ts-ignore
    loadMethods = {
        async listSpreadsheets(nodeData: INodeData, options: ICommonObject): Promise<INodeOptionsValue[]> {
            const returnData: INodeOptionsValue[] = []

            try {
                let credentialData = await getCredentialData(nodeData.credential ?? '', options)
                credentialData = await refreshOAuth2Token(nodeData.credential ?? '', credentialData, options)
                const accessToken = getCredentialParam('access_token', credentialData, nodeData)

                if (!accessToken) {
                    return returnData
                }

                // Query for Google Sheets files specifically
                const query = "mimeType='application/vnd.google-apps.spreadsheet' and trashed = false"

                const url = new URL('https://www.googleapis.com/drive/v3/files')
                url.searchParams.append('q', query)
                url.searchParams.append('pageSize', '100')
                url.searchParams.append('fields', 'files(id, name, modifiedTime, webViewLink)')
                url.searchParams.append('orderBy', 'modifiedTime desc')

                const response = await fetch(url.toString(), {
                    headers: {
                        Authorization: `Bearer ${accessToken}`,
                        'Content-Type': 'application/json'
                    }
                })

                if (!response.ok) {
                    console.error(`Failed to list spreadsheets: ${response.statusText}`)
                    return returnData
                }

                const data = await response.json()

                for (const file of data.files) {
                    const obj: INodeOptionsValue = {
                        name: file.id,
                        label: file.name,
                        description: `Modified: ${new Date(file.modifiedTime).toLocaleDateString()}`
                    }
                    returnData.push(obj)
                }
            } catch (error) {
                console.error('Error listing Google Sheets:', error)
            }

            return returnData
        }
    }

    async init(nodeData: INodeData, _: string, options: ICommonObject): Promise<any> {
        const _spreadsheetIds = nodeData.inputs?.spreadsheetIds as string
        const sheetNames = nodeData.inputs?.sheetNames as string
        const range = nodeData.inputs?.range as string
        const includeHeaders = nodeData.inputs?.includeHeaders as boolean
        const valueRenderOption = (nodeData.inputs?.valueRenderOption as string) || 'FORMATTED_VALUE'
        const textSplitter = nodeData.inputs?.textSplitter as TextSplitter
        const metadata = nodeData.inputs?.metadata
        const _omitMetadataKeys = nodeData.inputs?.omitMetadataKeys as string
        const output = nodeData.outputs?.output as string

        let omitMetadataKeys: string[] = []
        if (_omitMetadataKeys) {
            omitMetadataKeys = _omitMetadataKeys.split(',').map((key) => key.trim())
        }

        if (!_spreadsheetIds) {
            throw new Error('At least one spreadsheet is required')
        }

        let spreadsheetIds = convertMultiOptionsToStringArray(_spreadsheetIds)

        let credentialData = await getCredentialData(nodeData.credential ?? '', options)
        credentialData = await refreshOAuth2Token(nodeData.credential ?? '', credentialData, options)
        const accessToken = getCredentialParam('access_token', credentialData, nodeData)

        if (!accessToken) {
            throw new Error('No access token found in credential')
        }

        let docs: IDocument[] = []

        try {
            // Process each spreadsheet
            for (const spreadsheetId of spreadsheetIds) {
                try {
                    // Get spreadsheet metadata first
                    const spreadsheetMetadata = await this.getSpreadsheetMetadata(spreadsheetId, accessToken)

                    // Determine which sheets to load
                    let sheetsToLoad: string[] = []
                    if (sheetNames) {
                        sheetsToLoad = sheetNames.split(',').map((name) => name.trim())
                    } else {
                        // Get all sheet names from metadata
                        sheetsToLoad = spreadsheetMetadata.sheets?.map((sheet: any) => sheet.properties.title) || []
                    }

                    // Load data from each sheet
                    for (const sheetName of sheetsToLoad) {
                        const sheetRange = range ? `${sheetName}!${range}` : sheetName
                        const sheetData = await this.getSheetData(spreadsheetId, sheetRange, valueRenderOption, accessToken)

                        if (sheetData.values && sheetData.values.length > 0) {
                            const sheetDoc = this.convertSheetToDocument(
                                sheetData,
                                sheetName,
                                spreadsheetId,
                                spreadsheetMetadata,
                                includeHeaders
                            )
                            docs.push(sheetDoc)
                        }
                    }
                } catch (error) {
                    console.warn(`Failed to process spreadsheet ${spreadsheetId}: ${error.message}`)
                    // Continue processing other spreadsheets even if one fails
                }
            }

            // Apply text splitter if provided
            if (textSplitter && docs.length > 0) {
                docs = await textSplitter.splitDocuments(docs)
            }

            // Apply metadata transformations
            if (metadata) {
                const parsedMetadata = typeof metadata === 'object' ? metadata : JSON.parse(metadata)
                docs = docs.map((doc) => ({
                    ...doc,
                    metadata:
                        _omitMetadataKeys === '*'
                            ? {
                                  ...parsedMetadata
                              }
                            : omit(
                                  {
                                      ...doc.metadata,
                                      ...parsedMetadata
                                  },
                                  omitMetadataKeys
                              )
                }))
            } else {
                docs = docs.map((doc) => ({
                    ...doc,
                    metadata:
                        _omitMetadataKeys === '*'
                            ? {}
                            : omit(
                                  {
                                      ...doc.metadata
                                  },
                                  omitMetadataKeys
                              )
                }))
            }
        } catch (error) {
            throw new Error(`Failed to load Google Sheets data: ${error.message}`)
        }

        if (output === 'document') {
            return docs
        } else {
            let finaltext = ''
            for (const doc of docs) {
                finaltext += `${doc.pageContent}\n`
            }
            return handleEscapeCharacters(finaltext, false)
        }
    }

    private async getSpreadsheetMetadata(spreadsheetId: string, accessToken: string): Promise<any> {
        const url = `https://sheets.googleapis.com/v4/spreadsheets/${spreadsheetId}`

        const response = await fetch(url, {
            headers: {
                Authorization: `Bearer ${accessToken}`,
                'Content-Type': 'application/json'
            }
        })

        if (!response.ok) {
            const errorText = await response.text()
            throw new Error(`Failed to get spreadsheet metadata: ${response.status} ${response.statusText} - ${errorText}`)
        }

        return response.json()
    }

    private async getSheetData(spreadsheetId: string, range: string, valueRenderOption: string, accessToken: string): Promise<any> {
        const url = `https://sheets.googleapis.com/v4/spreadsheets/${spreadsheetId}/values/${encodeURIComponent(range)}`
        const params = new URLSearchParams({
            valueRenderOption,
            dateTimeRenderOption: 'FORMATTED_STRING',
            majorDimension: 'ROWS'
        })

        const response = await fetch(`${url}?${params}`, {
            headers: {
                Authorization: `Bearer ${accessToken}`,
                'Content-Type': 'application/json'
            }
        })

        if (!response.ok) {
            const errorText = await response.text()
            throw new Error(`Failed to get sheet data: ${response.status} ${response.statusText} - ${errorText}`)
        }

        return response.json()
    }

    private convertSheetToDocument(
        sheetData: any,
        sheetName: string,
        spreadsheetId: string,
        spreadsheetMetadata: any,
        includeHeaders: boolean
    ): IDocument {
        const values = sheetData.values || []

        if (values.length === 0) {
            return {
                pageContent: '',
                metadata: {
                    source: `Google Sheets: ${spreadsheetMetadata.properties?.title || 'Unknown'} - ${sheetName}`,
                    spreadsheetId,
                    sheetName,
                    spreadsheetTitle: spreadsheetMetadata.properties?.title,
                    range: sheetData.range,
                    rowCount: 0,
                    columnCount: 0
                }
            }
        }

        let headers: string[] = []
        let dataRows: string[][] = []

        if (includeHeaders && values.length > 0) {
            headers = values[0] || []
            dataRows = values.slice(1)
        } else {
            // Generate default headers like A, B, C, etc.
            const maxColumns = Math.max(...values.map((row: any[]) => row.length))
            headers = Array.from({ length: maxColumns }, (_, i) => String.fromCharCode(65 + i))
            dataRows = values
        }

        // Convert to markdown table format
        let content = ''

        if (headers.length > 0) {
            // Create header row
            content += '| ' + headers.join(' | ') + ' |\n'
            // Create separator row
            content += '| ' + headers.map(() => '---').join(' | ') + ' |\n'

            // Add data rows
            for (const row of dataRows) {
                const paddedRow = [...row]
                // Pad row to match header length
                while (paddedRow.length < headers.length) {
                    paddedRow.push('')
                }
                content += '| ' + paddedRow.join(' | ') + ' |\n'
            }
        }

        return {
            pageContent: content,
            metadata: {
                source: `Google Sheets: ${spreadsheetMetadata.properties?.title || 'Unknown'} - ${sheetName}`,
                spreadsheetId,
                sheetName,
                spreadsheetTitle: spreadsheetMetadata.properties?.title,
                spreadsheetUrl: `https://docs.google.com/spreadsheets/d/${spreadsheetId}`,
                range: sheetData.range,
                rowCount: values.length,
                columnCount: headers.length,
                headers: includeHeaders ? headers : undefined,
                totalDataRows: dataRows.length
            }
        }
    }
}

module.exports = { nodeClass: GoogleSheets_DocumentLoaders }