const cron = require('node-cron')
const Property = require('../components/property/propertyModel')
const propertyService = require('../components/property/propertyService')
const { client } = require('../setup/typesense')

let lastIndexedAt = new Date(0)
let lastIndexedCount = null
let isIndexing = false

const checkAndIndexProperties = async () => {
    if (isIndexing) {
        console.log('[Property Index Cron] Indexing already in progress. Skipping this run.')
        return
    }

    isIndexing = true
    try {
        const mongoCount = await Property.countDocuments({ isActive: true })

        // Check Typesense collection document count
        let typesenseCount = 0
        let collectionExists = false
        try {
            const collection = await client.collections('properties').retrieve()
            typesenseCount = collection.num_documents || 0
            collectionExists = true
        } catch (err) {
            collectionExists = false
        }

        // Count new or updated properties in MongoDB since last index
        const query = {
            isActive: true,
            $or: [
                { updatedAt: { $gt: lastIndexedAt } },
                { createdAt: { $gt: lastIndexedAt } }
            ]
        }
        const changedCount = await Property.countDocuments(query)

        const shouldIndex =
            !collectionExists ||
            (typesenseCount === 0 && mongoCount > 0) ||
            mongoCount !== typesenseCount ||
            (lastIndexedCount !== null && mongoCount !== lastIndexedCount) ||
            changedCount > 0

        if (shouldIndex) {
            console.log(
                `[Property Index Cron] Changes detected (MongoDB: ${mongoCount}, Typesense: ${typesenseCount}, New/Updated: ${changedCount}). Starting indexing...`
            )
            const result = await propertyService.indexAllProperties()
            lastIndexedAt = new Date()
            lastIndexedCount = mongoCount
            console.log(`[Property Index Cron] Successfully indexed ${result.totalCount} properties.`)
        } else {
            console.log(
                `[Property Index Cron] No new or updated properties found since ${lastIndexedAt.toISOString()} (MongoDB: ${mongoCount}, Typesense: ${typesenseCount}). Skipping.`
            )
        }
    } catch (err) {
        console.error('[Property Index Cron] Error during property indexing check:', err)
    } finally {
        isIndexing = false
    }
}

const startPropertyIndexCron = () => {
    // Schedule every 5 minutes
    const task = cron.schedule('*/5 * * * *', async () => {
        console.log('[Property Index Cron] Running scheduled 5-minute property index check...')
        await checkAndIndexProperties()
    })

    console.log('[Property Index Cron] Scheduled to run every 5 minutes (*/5 * * * *)')

    // Initial check after startup
    setTimeout(() => {
        checkAndIndexProperties().catch((err) => {
            console.error('[Property Index Cron] Initial index check failed:', err)
        })
    }, 10000)

    return task
}

module.exports = {
    startPropertyIndexCron,
    checkAndIndexProperties,
}