package org.terst.feedreader.data

import org.terst.feedreader.readability.ConsentNotice

/** What a cached `articles.extractedContent` value turned out to be worth. */
data class CachedExtraction(
    /** The content to show, or null if there is nothing usable. */
    val content: String?,
    /**
     * True when a cached consent notice was thrown away. The caller has nothing to
     * show and should extract again -- the cache is the reason the article looked
     * broken, so dropping it silently would just leave a blank reader.
     */
    val discardedConsentNotice: Boolean
)

/**
 * Reads a cached extraction, dropping it if it is the site's cookie/consent notice
 * rather than the article.
 *
 * Needed because the extractor's own guard can only keep a bad extraction from
 * being written in future. The reported bug ("reader mode just extracts cookie
 * disclaimer", with `extractedContent cached: true`) was already on disk: every
 * subsequent open read it straight back out, so no amount of fixing the extractor
 * would have changed what the user saw. A poisoned row is cleared here rather than
 * in a schema migration, so it is repaired whenever the article is next opened --
 * including for anything extracted before this check existed.
 *
 * [clearCache] is passed in rather than taking the DAO so this stays a plain
 * decision that can be tested without a database.
 */
suspend fun loadCachedExtraction(
    cached: String?,
    clearCache: suspend () -> Unit
): CachedExtraction {
    if (!ConsentNotice.looksLikeConsentNotice(cached)) {
        return CachedExtraction(content = cached, discardedConsentNotice = false)
    }
    clearCache()
    return CachedExtraction(content = null, discardedConsentNotice = true)
}