<?php
declare(strict_types=1);

use PHPUnit\Framework\TestCase;

/**
 * Tests for TMDO_Listing_Stats — Zone B/D integration.
 *
 * Tests view counter logic and flush-to-postmeta using
 * the same in-memory wpdb mock as ZoneWarmTest.
 */
class ListingStatsTest extends TestCase {

	/** In-memory warm store: post_id => meta_key => [value, expires_at] */
	public static array $store = [];

	/** Flushed view counts captured during flush_views_to_postmeta(). */
	public static array $flushed = [];

	protected function setUp(): void {
		self::$store   = [];
		self::$flushed = [];
		$GLOBALS['_wp_postmeta'] = [];
		$this->setupWpdbMock();
	}

	private function setupWpdbMock(): void {
		global $wpdb;

		$wpdb = new class {
			public string $prefix   = 'wp_';
			public string $postmeta = 'wp_postmeta';
			public string $posts    = 'wp_posts';

			public function prepare( string $sql, ...$args ): string {
				$i = 0;
				return preg_replace_callback( '/%([sd])/', function ( $m ) use ( &$i, $args ) {
					$val = $args[ $i++ ] ?? '';
					return $m[1] === 'd' ? (string) (int) $val : "'" . addslashes( (string) $val ) . "'";
				}, $sql );
			}

			public function get_var( string $sql ): ?string {
				$store = &ListingStatsTest::$store;
				// Normalize whitespace so multiline SQL works with regex.
				$flat = preg_replace( '/\s+/', ' ', $sql );
				if ( preg_match( '/SELECT id.*post_id = (\d+).*meta_key = \'([^\']+)\'/', $flat, $m ) ) {
					return isset( $store[ $m[1] ][ $m[2] ] ) ? '1' : null;
				}
				if ( preg_match( '/SELECT meta_value.*post_id = (\d+).*meta_key = \'([^\']+)\'/', $flat, $m ) ) {
					$entry = $store[ $m[1] ][ $m[2] ] ?? null;
					if ( ! $entry ) {
						return null;
					}
					if ( $entry['expires_at'] && $entry['expires_at'] < time() ) {
						return null;
					}
					return $entry['value'];
				}
				return null;
			}

			public function get_results( string $sql, $output = null ): array {
				$flat = preg_replace( '/\s+/', ' ', $sql );

				// Postmeta batch query (e.g. hp_view_count) → read from $GLOBALS['_wp_postmeta'].
				if ( strpos( $flat, 'wp_postmeta' ) !== false ) {
					$result = [];
					foreach ( $GLOBALS['_wp_postmeta'] ?? [] as $post_id => $meta ) {
						if ( isset( $meta['hp_view_count'] ) ) {
							$row = [ 'post_id' => (string) $post_id, 'meta_value' => (string) $meta['hp_view_count'] ];
							$result[] = $output === ARRAY_A ? $row : (object) $row;
						}
					}
					return $result;
				}

				// Warm zone query → return from store, filtered by meta_key in SQL.
				$store      = ListingStatsTest::$store;
				$result     = [];
				$filter_key = null;
				if ( preg_match( "/meta_key = '([^']+)'/", $flat, $m ) ) {
					$filter_key = $m[1];
				}
				foreach ( $store as $post_id => $keys ) {
					foreach ( $keys as $meta_key => $entry ) {
						if ( $filter_key && $meta_key !== $filter_key ) {
							continue;
						}
						if ( $entry['expires_at'] && $entry['expires_at'] < time() ) {
							continue;
						}
						$row = [ 'post_id' => $post_id, 'meta_key' => $meta_key, 'meta_value' => $entry['value'] ];
						$result[] = $output === ARRAY_A ? $row : (object) $row;
					}
				}
				return $result;
			}

			public function insert( string $table, array $data, $format = null ): int|false {
				ListingStatsTest::$store[ $data['post_id'] ][ $data['meta_key'] ] = [
					'value'      => $data['meta_value'],
					'expires_at' => isset( $data['expires_at'] ) ? strtotime( $data['expires_at'] ) : null,
				];
				return 1;
			}

			public function update( string $table, array $data, array $where, $f1 = null, $f2 = null ): int|false {
				// Scan store and update matching entries (where clause uses id=1 placeholder).
				foreach ( ListingStatsTest::$store as $post_id => &$keys ) {
					foreach ( $keys as $meta_key => &$entry ) {
						if ( isset( $data['meta_value'] ) ) {
							$entry['value'] = $data['meta_value'];
						}
						if ( isset( $data['expires_at'] ) ) {
							$entry['expires_at'] = strtotime( $data['expires_at'] );
						}
					}
				}
				return 1;
			}

			public function delete( string $table, array $where, $format = null ): int|false {
				$post_id  = $where['post_id'] ?? null;
				$meta_key = $where['meta_key'] ?? null;

				if ( $post_id && $meta_key ) {
					unset( ListingStatsTest::$store[ $post_id ][ $meta_key ] );
				} elseif ( $post_id ) {
					unset( ListingStatsTest::$store[ $post_id ] );
				}
				return 1;
			}

			public function query( string $sql ): int|bool {
				$store = &ListingStatsTest::$store;
				$flat  = preg_replace( '/\s+/', ' ', $sql );

				// Atomic postmeta increment — from flush_views_to_postmeta (P1-22).
				// SQL: UPDATE `wp_postmeta` SET meta_value = meta_value + N WHERE post_id = P AND meta_key = 'hp_view_count'
				if ( stripos( $flat, 'meta_value = meta_value +' ) !== false ) {
					if ( preg_match( '/meta_value = meta_value \+ (\d+).*post_id = (\d+)/i', $flat, $m ) ) {
						$by      = (int) $m[1];
						$post_id = (int) $m[2];
						if ( isset( $GLOBALS['_wp_postmeta'][ $post_id ]['hp_view_count'] ) ) {
							$GLOBALS['_wp_postmeta'][ $post_id ]['hp_view_count'] += $by;
							return 1;
						}
					}
					return 0; // no existing row — caller will add_post_meta
				}

				// INSERT ... ON DUPLICATE KEY UPDATE (from set() via TMDO_DB::upsert())
				if ( stripos( $flat, 'ON DUPLICATE KEY' ) !== false && stripos( $flat, 'COALESCE' ) === false ) {
					if ( preg_match( "/VALUES \((\d+), '([^']+)', '([^']*)', (NULL|'[^']+'), '[^']+'\)/i", $flat, $m ) ) {
						$post_id    = (int) $m[1];
						$meta_key   = $m[2];
						$meta_value = $m[3];
						$expires_at = $m[4] === 'NULL' ? null : strtotime( trim( $m[4], "'" ) );
						$store[ $post_id ][ $meta_key ] = [
							'value'      => $meta_value,
							'expires_at' => $expires_at,
						];
						return 1;
					}
				}

				// INSERT ... ON DUPLICATE KEY UPDATE meta_value = CAST(COALESCE...) + N (from increment())
				if ( stripos( $flat, 'COALESCE' ) !== false ) {
					if ( preg_match( "/VALUES \((\d+), '([^']+)', (\d+),/i", $flat, $m ) ) {
						$post_id  = (int) $m[1];
						$meta_key = $m[2];
						$by       = (int) $m[3];
						$current  = (int) ( $store[ $post_id ][ $meta_key ]['value'] ?? 0 );
						$store[ $post_id ][ $meta_key ] = [
							'value'      => (string) ( $current + $by ),
							'expires_at' => null,
						];
						return 1;
					}
				}

				return 0;
			}
		};
	}

	// ── increment_view ───────────────────────────────────────────────────────

	public function test_increment_view_starts_at_one(): void {
		TMDO_Listing_Stats::increment_view( 10 );
		$this->assertSame( '1', TMDO_Zone_Warm::get( 10, TMDO_Listing_Stats::VIEW_KEY ) );
	}

	public function test_increment_view_accumulates(): void {
		TMDO_Listing_Stats::increment_view( 10 );
		TMDO_Listing_Stats::increment_view( 10 );
		TMDO_Listing_Stats::increment_view( 10 );
		$this->assertSame( '3', TMDO_Zone_Warm::get( 10, TMDO_Listing_Stats::VIEW_KEY ) );
	}

	// ── get_view_count ───────────────────────────────────────────────────────

	public function test_get_view_count_reads_warm_zone_first(): void {
		TMDO_Listing_Stats::increment_view( 20 );
		TMDO_Listing_Stats::increment_view( 20 );

		// postmeta has 0 (default), warm has 2.
		$this->assertSame( 2, TMDO_Listing_Stats::get_view_count( 20 ) );
	}

	public function test_get_view_count_falls_back_to_postmeta(): void {
		// No warm entry → falls back to postmeta.
		$GLOBALS['_wp_postmeta'][30]['hp_view_count'] = 99;
		$this->assertSame( 99, TMDO_Listing_Stats::get_view_count( 30 ) );
	}

	public function test_get_view_count_returns_zero_when_empty(): void {
		$this->assertSame( 0, TMDO_Listing_Stats::get_view_count( 999 ) );
	}

	// ── flush_views_to_postmeta ──────────────────────────────────────────────

	public function test_flush_moves_count_to_postmeta(): void {
		TMDO_Listing_Stats::increment_view( 40 );
		TMDO_Listing_Stats::increment_view( 40 );

		$flushed = TMDO_Listing_Stats::flush_views_to_postmeta();

		$this->assertSame( 1, $flushed );
		$this->assertSame( 2, (int) ( $GLOBALS['_wp_postmeta'][40]['hp_view_count'] ?? 0 ) );
	}

	public function test_flush_clears_warm_entry(): void {
		TMDO_Listing_Stats::increment_view( 50 );
		TMDO_Listing_Stats::flush_views_to_postmeta();

		$this->assertNull( TMDO_Zone_Warm::get( 50, TMDO_Listing_Stats::VIEW_KEY ) );
	}

	public function test_flush_returns_zero_when_no_warm_entries(): void {
		$this->assertSame( 0, TMDO_Listing_Stats::flush_views_to_postmeta() );
	}

	public function test_flush_accumulates_on_top_of_existing_postmeta(): void {
		$GLOBALS['_wp_postmeta'][60]['hp_view_count'] = 10;
		TMDO_Listing_Stats::increment_view( 60 );
		TMDO_Listing_Stats::increment_view( 60 );
		TMDO_Listing_Stats::flush_views_to_postmeta();

		$this->assertSame( 12, (int) ( $GLOBALS['_wp_postmeta'][60]['hp_view_count'] ?? 0 ) );
	}
}