import EventSource from 'eventsource';
import axios from 'axios';
import { URL } from 'url';
import { Client as NotionClient } from '@notionhq/client';
import { NotionToMarkdown } from 'notion-to-md';
import {
    CustomActionModel,
    CustomActionRunCommonOptions,
    CustomActionModelRunOptions,
    CustomActionInputField,
    CustomActionProgressFunction,
    ModelMap,
    Logger
} from '@stackbit/types';

export type GenerateContentFromPresetOptions = {
    /**
     * The label for the AI action.
     * @default Generate content with AI
     */
    label?: string;
    /**
     * The name of the field that contains the page's section.
     * For example, 'sections', 'blocks', 'components'.
     * Use `modelsConfig.mailListField` when setting root config actions.
     */
    mainListField?: string;
    /**
     * Custom AI prompt.
     * Use `modelsConfig.customPrompt` when setting root config actions.
     */
    customPrompt?: string;
    /**
     * Allow content editor to change the custom prompt.
     */
    allowOverrideCustomPrompt?: boolean;
    /**
     * Use `modelsConfig` when setting root config actions, and specify
     * `mainListField` and `customPrompt` per model `name`.
     */
    modelsConfig?: {
        name: string;
        mainListField?: string;
        customPrompt?: string;
    }[];
    /**
     * Temporary solution to connect the action with site related AI-knowledge.
     */
    siteId?: string;
};

function GenerateContentFromPreset({
    label,
    mainListField,
    customPrompt,
    allowOverrideCustomPrompt,
    modelsConfig,
    siteId
}: GenerateContentFromPresetOptions): CustomActionModel {
    return {
        type: 'model',
        name: '_create_from_preset_ai',
        label: label ?? 'Generate content with AI',
        models: modelsConfig ? modelsConfig.map((model) => model.name) : undefined,
        inputFields: [
            {
                type: 'slug',
                name: 'slug',
                label: 'Slug'
            },
            ...(siteId
                ? [
                      {
                          type: 'string',
                          name: '_spark_ai_site_id',
                          hidden: true,
                          default: siteId
                      } satisfies CustomActionInputField
                  ]
                : []),
            ...(allowOverrideCustomPrompt
                ? [
                      {
                          type: 'text',
                          name: 'customPrompt',
                          label: 'Custom Prompt',
                          default: customPrompt
                      } satisfies CustomActionInputField
                  ]
                : [])
        ],
        run: async (options: CustomActionRunCommonOptions & CustomActionModelRunOptions) => {
            const logger = options.getLogger();
            logger.info(`generate content from preset`);

            const schemas = options.getSchemas();
            const modelsByName: ModelMap = {};
            for (const schema of schemas) {
                for (const model of schema.models) {
                    modelsByName[model.name] = model;
                }
            }

            const sparkClient = new SparkClient({ logger });

            const modelConf = (modelsConfig ?? []).find((model) => model.name === options.actionModel.name);
            if (modelConf) {
                mainListField = modelConf.mainListField ?? mainListField;
                customPrompt = modelConf.customPrompt ?? customPrompt;
            }

            const progressCallback = createProgressCallback(options.progress);

            progressCallback({
                percent: 0,
                categoryMessage: 'Initializing',
                progressMessage: 'Initializing'
            });

            const contentMarkdown = await fetchContent(options, progressCallback, logger);

            if (!contentMarkdown || contentMarkdown.length === 0) {
                throw new Error('Content must not be empty');
            }

            const result = await sparkClient.performContentGen({
                contentMarkdown,
                knowledge: getKnowledgeForInputData(options.inputData),
                preset: options.inputData?.presetData,
                customPrompt: options.inputData?.customPrompt ?? customPrompt,
                modelName: options.actionModel.name,
                sectionsField: mainListField,
                engineName: 'openai',
                modelsByName,
                progressCallback
            });

            if (options.inputData?.slug) {
                result.slug = options.inputData?.slug;
            }

            logger.info('create document');
            progressCallback({
                percent: 95,
                categoryMessage: 'Saving content',
                progressMessage: 'Saving content'
            });
            const { documentId } = await options.contentSourceActions.createDocumentFromObject({
                modelName: options.actionModel.name,
                object: result
            });
            logger.info(`created document with ID: '${documentId}'`);
            return {
                success: 'Successfully generated document',
                result: { documentId }
            };
        }
    };
}

class SparkClient {
    private readonly logger: Logger;

    constructor({ logger }: { logger: any }) {
        this.logger = logger;
    }

    async performContentGen({
        contentMarkdown,
        knowledge,
        preset,
        modelName,
        sectionsField,
        customPrompt,
        engineName,
        modelsByName,
        progressCallback
    }: {
        contentMarkdown: string;
        knowledge?: SparkKnowledge;
        preset: any;
        modelName: string;
        sectionsField?: string;
        customPrompt?: string;
        engineName?: string;
        modelsByName: Record<string, any>;
        progressCallback: ProgressCallback;
    }) {
        const presetData = JSON.stringify(preset);
        const modelsByNameData = JSON.stringify(modelsByName);

        this.logger.debug('initialize content-gen workload');

        const baseUrl = process.env.SPARK_URL ?? 'https://api-create.services.netlify.com/spark';
        const initializedWorkloadResult = await axios({
            url: `${baseUrl}/api/v1/workload/content-gen`,
            method: 'post',
            headers: {
                'Content-Type': 'application/json',
                ...(process.env.SPARK_API_KEY
                    ? {
                          'x-spark-api-key': process.env.SPARK_API_KEY
                      }
                    : null)
            },
            data: {
                inputs: {
                    model: modelName,
                    engine: engineName ?? 'openai',
                    sectionsField: sectionsField,
                    customPrompt: customPrompt
                },
                uploads: {
                    createData: {
                        preset: hashCode(presetData),
                        modelsByName: hashCode(modelsByNameData)
                    },
                    sourceData: {
                        sourceContent: hashCode(contentMarkdown)
                    }
                },
                knowledge
            }
        }).catch((error) => {
            throw new Error(`Failed to initialize AI workload: ${error.message}`);
        });

        // all of our signed urls are set on this workload result object.
        const workloadData = initializedWorkloadResult.data;
        this.logger.debug('initialized workload');

        if (!workloadData.startWorkload) {
            throw new Error('Workload does not contain startWorkload URL');
        }

        // upload the resources we specified that we would upload on the original init call
        this.logger.debug('uploading workload createData');
        progressCallback({
            percent: 5,
            categoryMessage: 'Initializing',
            progressMessage: 'Uploading content'
        });
        await Promise.all([
            axios({
                url: workloadData.requiredUploads.createData.preset,
                method: 'post',
                headers: { 'Content-Type': 'application/json' },
                data: preset
            }),
            axios({
                url: workloadData.requiredUploads.createData.modelsByName,
                method: 'post',
                headers: { 'Content-Type': 'application/json' },
                data: modelsByName
            }),
            axios({
                url: workloadData.requiredUploads.sourceData.sourceContent,
                method: 'post',
                headers: { 'Content-Type': 'application/json' },
                data: contentMarkdown
            })
        ]).catch((error) => {
            throw new Error(`Failed to upload data to AI workload: ${error.message}`);
        });

        // now that all files are uploaded, kick off the workload
        await axios({
            url: workloadData.startWorkload,
            method: 'post'
        }).catch((error) => {
            throw new Error(`Failed to start AI workload: ${error.message}`);
        });
        this.logger.debug('started workload');

        // wait until the workload is done
        await this.waitUntilDone({
            sseUrl: workloadData.progress.sse,
            progressCallback: (sparkEvent: SparkEvent) => {
                progressCallback(null, sparkEvent);
            }
        });

        progressCallback({
            percent: 90,
            categoryMessage: 'Transforming content',
            progressMessage: 'Content transformation completed'
        });

        // fetch the result
        this.logger.debug('workload finished, fetching workload result');
        const workloadResult = await axios({
            url: workloadData.workloadResult,
            method: 'get'
        }).catch((error) => {
            throw new Error(`Failed to get AI workload result: ${error.message}`);
        });
        this.logger.debug('got workload result', {
            status: workloadResult.status,
            statusText: workloadResult.statusText
        });

        return workloadResult.data;
    }

    waitUntilDone({
        sseUrl,
        progressCallback,
        retryCount = 0
    }: {
        sseUrl: string;
        progressCallback?: (sparkEvent: SparkEvent) => void;
        retryCount?: number;
    }): Promise<void> {
        this.logger.debug('subscribe to server-side-events', { retryCount });
        const sse = new EventSource(sseUrl);
        return new Promise((resolve, reject) => {
            sse.onerror = (event) => {
                sse.close();
                this.logger.error('server-side-event error', { event });
                if (retryCount < 3) {
                    setTimeout(() => {
                        resolve(
                            this.waitUntilDone({
                                sseUrl,
                                progressCallback,
                                retryCount: retryCount + 1
                            })
                        );
                    }, 1000);
                } else {
                    this.logger.error('got 3 server-side-event errors, aborting');
                    reject(new Error('AI Workload failed: could not establish SSE channel'));
                }
            };

            sse.addEventListener('message', (event) => {
                this.logger.debug('eventsource event:', { event });
                try {
                    const sparkEvent = JSON.parse(event.data) as SparkEvent;
                    if (!sparkEvent.latest) {
                        return;
                    }
                    const percentage = sparkEvent.latest.percentage;
                    if (typeof percentage === 'number' && percentage >= 100) {
                        sse.close();
                        if (sparkEvent.latest.systemFailure) {
                            reject(new Error(`AI Workload failed: ${sparkEvent.latest.errorMessage}`));
                        } else {
                            resolve();
                        }
                    } else {
                        progressCallback?.(sparkEvent);
                    }
                } catch (error) {
                    sse.close();
                    reject(new Error('AI Workload failed: could not parse Spark event'));
                }
            });
        });
    }
}

type SparkEvent = {
    latest?: SparkEventProgressMessage;
    allProgress?: SparkEventProgressMessage[];
};

type SparkEventProgressMessage = {
    percentage?: number;
    categoryMessage?: string;
    progressMessage?: string;
    systemFailure?: boolean;
    errorMessage?: string;
};

type ProgressCallback = (localEvent: { percent: number; categoryMessage: string; progressMessage: string } | null, remoteSparkEvent?: SparkEvent) => void;

function createProgressCallback(progressCallback: CustomActionProgressFunction): ProgressCallback {
    const localProgressBefore: SparkEventProgressMessage[] = [];
    const localProgressAfter: SparkEventProgressMessage[] = [];
    let remoteProgress: SparkEventProgressMessage[] = [];
    let gotRemoteEvents = false;

    const adjustPercentage = (percentage?: number) => {
        return 10 + Math.round((percentage ?? 0) * 0.8);
    };

    return (localEvent: { percent: number; categoryMessage: string; progressMessage: string } | null, remoteSparkEvent?: SparkEvent) => {
        let sparkEvent: SparkEvent | undefined;
        if (remoteSparkEvent) {
            gotRemoteEvents = true;
            remoteProgress =
                remoteSparkEvent.allProgress?.map((step) => {
                    return {
                        ...step,
                        percentage: adjustPercentage(step.percentage)
                    };
                }) ?? remoteProgress;
            if (remoteSparkEvent.latest) {
                sparkEvent = {
                    ...remoteSparkEvent,
                    latest: {
                        ...remoteSparkEvent.latest,
                        percentage: adjustPercentage(remoteSparkEvent.latest.percentage)
                    },
                    allProgress: localProgressBefore.concat(remoteProgress ?? [])
                };
            }
        } else if (localEvent) {
            const latest = createSparkEventProgressMessage(localEvent);
            if (!gotRemoteEvents) {
                localProgressBefore.push(latest);
                sparkEvent = {
                    latest,
                    allProgress: localProgressBefore
                };
            } else {
                localProgressAfter.push(latest);
                sparkEvent = {
                    latest,
                    allProgress: localProgressBefore.concat(remoteProgress, localProgressAfter)
                };
            }
        }
        if (sparkEvent?.latest) {
            progressCallback?.({
                percent: sparkEvent.latest?.percentage,
                message: JSON.stringify(sparkEvent)
            });
        }
    };
}

function createSparkEventProgressMessage(options: {
    percent: number;
    categoryMessage: string;
    progressMessage: string;
    systemFailure?: boolean;
    errorMessage?: string;
}): SparkEventProgressMessage {
    return {
        percentage: options.percent,
        categoryMessage: options.categoryMessage,
        progressMessage: options.progressMessage,
        systemFailure: options.systemFailure,
        errorMessage: options.errorMessage
    };
}

function hashCode(str: string) {
    let hash = 0;
    for (let i = 0; i < str.length; i++) {
        const code = str.charCodeAt(i);
        hash = (hash << 5) - hash + code;
        hash = hash & hash; // Convert to 32bit integer
    }
    return hash;
}

type SparkKnowledge = {
    scopes: ScopeSelections;
    selected: SparkKnowledgeSelection[];
};

type ScopeSelections = {
    shared?: 'netlify-known' | 'public';
    orgId?: string;
    accountId?: string;
    siteId?: string;
};

type SparkKnowledgeSelection = {
    type: string;
    scopeType?: keyof ScopeSelections;
    id?: string;
};

function getKnowledgeForInputData(inputData?: Record<string, any>): SparkKnowledge | undefined {
    if (!inputData) {
        return undefined;
    }
    if (inputData._spark_ai_knowledge) {
        return inputData._spark_ai_knowledge;
    }
    const selected: SparkKnowledgeSelection[] = [];
    if (inputData._spark_ai_voiceTone) {
        selected.push({
            type: 'voice-and-tone',
            id: inputData._spark_ai_voiceTone
        });
    }
    if (inputData._spark_ai_targetAudience) {
        selected.push({
            type: 'target-audience',
            id: inputData._spark_ai_targetAudience
        });
    }
    if (selected.length === 0) {
        return undefined;
    }
    return {
        scopes: {
            shared: 'netlify-known'
        },
        selected
    };
}

async function fetchContent(options: CustomActionRunCommonOptions, progressCallback: ProgressCallback, logger: Logger): Promise<string> {
    const googleDoc = await fetchGoogleDoc(options, progressCallback, logger);
    if (googleDoc) {
        logger.debug('Got Google doc');
        return googleDoc;
    }

    const notionPage = await fetchNotionPage(options, progressCallback, logger);
    if (notionPage) {
        logger.debug('Got Notion page');
        return notionPage;
    }

    return options.inputData?._spark_ai_content;
}

async function fetchGoogleDoc(options: CustomActionRunCommonOptions, progressCallback: ProgressCallback, logger: Logger): Promise<string | undefined> {
    const googleDocUrl = options.inputData?._spark_ai_googleDocUrl ?? options.inputData?._spark_ai_content;
    const match = googleDocUrl?.match(/docs\.google\.com\/document\/d\/([^/?#]+)/);
    if (!match) {
        return;
    }
    const googleDocId = match[1];
    if (!googleDocId) {
        return;
    }

    logger.debug('Found Google doc URL');

    let googleConnection;
    if (options.currentUser && 'connections' in options.currentUser && Array.isArray(options.currentUser.connections)) {
        googleConnection = options.currentUser.connections.find((connection) => connection.type === 'google');
    }
    if (!googleConnection || !('accessToken' in googleConnection)) {
        logger.debug('User does not have Google connection');
        throw new Error('Please connect your Google account');
    }

    progressCallback({
        percent: 2,
        categoryMessage: 'Initializing',
        progressMessage: `Fetching from ${googleDocUrl}`
    });

    logger.debug('Fetching Google doc');
    // const url = `https://docs.google.com/feeds/download/documents/export/Export?id=${documentId}&exportFormat=markdown`;
    const url = `https://www.googleapis.com/drive/v3/files/${googleDocId}/export?mimeType=text/markdown`;
    const googleDocResult = await axios({
        url: url,
        method: 'get',
        headers: {
            Authorization: `Bearer ${googleConnection.accessToken}`
        }
    }).catch((error) => {
        throw new Error(`Failed to fetch Google doc: ${error.message}`);
    });
    return googleDocResult.data;
}

async function fetchNotionPage(options: CustomActionRunCommonOptions, progressCallback: ProgressCallback, logger: Logger): Promise<string | undefined> {
    // Example for notion page URLs
    // https://www.notion.so/{COMPANY_SLUG}/{PAGE_SLUG}-{PAGE_ID}
    // https://www.notion.so/{PAGE_ID}
    // https://notion.so/{PAGE_SLUG}-{PAGE_ID}
    const notionUrl = options.inputData?._spark_ai_notionUrl ?? options.inputData?._spark_ai_content;
    if (!/notion\.so\//.test(notionUrl)) {
        return undefined;
    }
    let urlObject: URL;
    try {
        urlObject = new URL(notionUrl);
    } catch (error) {
        return undefined;
    }
    if (!['www.notion.so', 'notion.so'].includes(urlObject.hostname)) {
        return undefined;
    }

    // The notion page ID is encoded into the last section of the URL path after the last hyphen
    // https://www.notion.so/Hello-World-12a4dc5adgh230e5ad5ad56456b457d9
    //                                   ↳        Notion Page ID        ↲
    const pathParts = urlObject.pathname.replace(/^\//, '').split('/');
    const notionPageSlugAndId = pathParts[pathParts.length - 1];
    if (!notionPageSlugAndId) {
        return undefined;
    }
    const pageSlugAndIdParts = notionPageSlugAndId.split('-');
    const notionPageId = pageSlugAndIdParts[pageSlugAndIdParts.length - 1];
    if (!notionPageId) {
        return undefined;
    }

    logger.debug(`Found Notion page URL with ID: ${notionPageId}`);

    let notionConnection;
    if (options.currentUser && 'connections' in options.currentUser && Array.isArray(options.currentUser.connections)) {
        notionConnection = options.currentUser.connections.find((connection) => connection.type === 'notion');
    }
    if (!notionConnection || !('accessToken' in notionConnection)) {
        logger.debug('User does not have Notion connection');
        throw new Error('Please connect your Notion account');
    }

    progressCallback({
        percent: 2,
        categoryMessage: 'Initializing',
        progressMessage: `Fetching from ${notionUrl}`
    });

    logger.debug('Fetching Notion page');
    const notionClient = new NotionClient({ auth: notionConnection.accessToken });
    const n2m = new NotionToMarkdown({ notionClient });
    const mdBlocks = await n2m.pageToMarkdown(notionPageId);
    const mdString = n2m.toMarkdownString(mdBlocks);
    return mdString.parent;
}

export const Actions = {
    GenerateContentFromPreset
};