const { apiSsrBaseURL, ssrPublishCheckCollections } = require("../config")

/**
 * api request via server, cache result in context.ssrCache
 * should be elimated in client code via tree shaking
 *
 * @param {string} cacheKey
 * @param {string} endpoint
 * @param {string} query
 * @param {ApiOptions} options
 * @returns {ApiResult<any>}
 */
function ssrRequest(cacheKey, endpoint, query, options) {
    let url = endpoint + (query ? "?" + query : "")

    // track which collections/entries contribute to this SSR render
    // endpoint may contain path segments (e.g. "content/abc123") or query strings
    const collectionName = endpoint.split("?")[0].split("/")[0]

    if (ssrPublishCheckCollections?.includes(endpoint)) {
        // @ts-ignore
        let validUntil = context.ssrCacheValidUntil

        // check in db for publish date to invalidate cache
        const _optionsPublishSearch = Object.assign(
            {},
            { filter: options?.filter },
            {
                selector: { publication: 1 },
                projection: null,
            }
        )
        const publishSearch = context.db.find(endpoint, _optionsPublishSearch)
        publishSearch?.forEach((item) => {
            const publicationFrom = item.publication?.from ? new Date(item.publication.from.unixMilli()) : null
            const publicationTo = item.publication?.to ? new Date(item.publication.to.unixMilli()) : null

            if (publicationFrom && publicationFrom > new Date()) {
                // entry has a publish date that is further in in the future than current, set global validUntil
                if (validUntil == null || validUntil > publicationFrom) {
                    validUntil = publicationFrom
                }
            }
            if (publicationTo && publicationTo > new Date()) {
                // entry has a unpublish date that is further in in the future than current, set global validUntil
                if (validUntil == null || validUntil > publicationTo) {
                    validUntil = publicationTo
                }
            }
        })
        // @ts-ignore
        context.ssrCacheValidUntil = validUntil
    }

    // console.log("############ FETCHING ", apiSsrBaseURL + url)

    const response = context.http.fetch(apiSsrBaseURL + url, {
        method: options.method,
        headers: options.headers,
    })

    // console.log(JSON.stringify(response.headers, null, 2))

    const json = response.body.json()
    const count = parseInt(response.headers["X-Results-Count"] || "0")

    // json is go data structure and incompatible with js, so we need to convert it
    const r = { data: JSON.parse(JSON.stringify(json)), count: count }

    // track dependencies: "col:id" for single-entry, "col:*" for list queries
    // @ts-ignore – dynamic property set by get_read.js
    if (context.ssrDeps) {
        let entryId = null

        if (!Array.isArray(r.data) && r.data && r.data.id) {
            // direct ID lookup (COLLECTION/ID) – API returned single object
            entryId = r.data.id
        } else if (options?.limit === 1 && Array.isArray(r.data) && r.data.length === 1 && r.data[0] && r.data[0].id) {
            // filter-based detail query with limit:1
            entryId = r.data[0].id
        }

        if (entryId) {
            // @ts-ignore
            context.ssrDeps[collectionName + ":" + entryId] = true
        } else {
            // list query – any change to this collection affects this page
            // @ts-ignore
            context.ssrDeps[collectionName + ":*"] = true
        }

        // --- EXTENSION: Track dependencies from lookup and aggregate ---
        // Both `lookup` and `aggregate` parameters can inject data from other collections.
        // We must invalidate the SSR cache if any of those referenced collections change.
        if (options && options.lookup) {
            const lookups = typeof options.lookup === "string" ? options.lookup.split(",") : [];
            for (const l of lookups) {
                // format: "fieldPath:collectionName"
                const parts = l.split(":");
                if (parts.length > 1) {
                    const targetCollection = parts[parts.length - 1];
                    // @ts-ignore
                    context.ssrDeps[targetCollection + ":*"] = true;
                }
            }
        }
        if (options && options.params && options.params.aggregate) {
            const aggregates = typeof options.params.aggregate === "string" 
                ? options.params.aggregate.split(",") 
                : [];
            for (const a of aggregates) {
                // simple format: "collectionName:foreignField:..."
                // json format: '{"collection":"comments",...}'
                try {
                    if (a.startsWith("{")) {
                        const parsed = JSON.parse(a);
                        if (parsed && parsed.collection) {
                            // @ts-ignore
                            context.ssrDeps[parsed.collection + ":*"] = true;
                        }
                    } else {
                        const parts = a.split(":");
                        if (parts.length > 0) {
                            const targetCollection = parts[0];
                            // @ts-ignore
                            context.ssrDeps[targetCollection + ":*"] = true;
                        }
                    }
                } catch (e) {
                    // silently ignore parse errors here
                }
            }
        }
        // --- END EXTENSION ---
    }

    // @ts-ignore
    context.ssrCache[cacheKey] = r

    return r
}

module.exports = {
    ssrRequest,
}