<?php
/**
 * Metrics Repository for Analytics Dashboard
 *
 * @package ROI_APU_Search
 * @since 1.2.0
 */

declare(strict_types=1);

// Prevent direct access
if (!defined('ABSPATH')) {
    exit;
}

/**
 * Repository class for dashboard metrics queries
 */
final class ROI_APU_Metrics_Repository
{
    private PDO $pdo;
    private string $prefix;

    /**
     * Constructor
     *
     * @param PDO $pdo Database connection
     * @param string $prefix Table prefix
     */
    public function __construct(PDO $pdo, string $prefix)
    {
        $this->pdo = $pdo;
        $this->prefix = $prefix;
    }

    /**
     * Get KPIs for dashboard with trends vs previous period
     *
     * @param int $days Number of days to query
     * @return array{total_busquedas: int, pct_sin_resultados: float, clicks: int, ctr: float, pos_prom: float, trends: array}
     */
    public function getKPIs(int $days = 30): array
    {
        // Default values
        $result = [
            'total_busquedas' => 0,
            'pct_sin_resultados' => 0.0,
            'clicks' => 0,
            'ctr' => 0.0,
            'pos_prom' => 0.0,
            'trends' => [
                'busquedas' => 0.0,
                'ctr' => 0.0,
                'sin_resultados' => 0.0,
                'pos_prom' => 0.0,
            ],
        ];

        try {
            // Query 1: Basic KPIs from searches table
            $sql1 = "SELECT
                COUNT(*) as total_busquedas,
                ROUND(SUM(zero_results)*100.0/NULLIF(COUNT(*), 0), 2) as pct_sin_resultados
            FROM {$this->prefix}rcp_paginas_querys
            WHERE ts >= DATE_SUB(NOW(), INTERVAL :days DAY)";

            $stmt1 = $this->pdo->prepare($sql1);
            $stmt1->execute(['days' => $days]);
            $row1 = $stmt1->fetch();

            if ($row1) {
                $result['total_busquedas'] = (int) ($row1['total_busquedas'] ?? 0);
                $result['pct_sin_resultados'] = (float) ($row1['pct_sin_resultados'] ?? 0);
            }

            // Query 2: Clicks, CTR (correct calculation), and average position
            // CTR = búsquedas con al menos 1 click / total búsquedas
            $sql2 = "SELECT
                COUNT(*) as clicks,
                COUNT(DISTINCT search_id) as busquedas_con_click,
                ROUND(AVG(position), 1) as pos_prom
            FROM {$this->prefix}rcp_paginas_querys_log
            WHERE ts >= DATE_SUB(NOW(), INTERVAL :days DAY)";

            $stmt2 = $this->pdo->prepare($sql2);
            $stmt2->execute(['days' => $days]);
            $row2 = $stmt2->fetch();

            if ($row2) {
                $result['clicks'] = (int) ($row2['clicks'] ?? 0);
                $result['pos_prom'] = (float) ($row2['pos_prom'] ?? 0);

                // Calculate CTR correctly: distinct searches with clicks / total searches
                $busquedasConClick = (int) ($row2['busquedas_con_click'] ?? 0);
                if ($result['total_busquedas'] > 0) {
                    $result['ctr'] = round(($busquedasConClick / $result['total_busquedas']) * 100, 1);
                }
            }

            // Query 3: Previous period for trends comparison
            $sqlPrev1 = "SELECT
                COUNT(*) as total_busquedas,
                ROUND(SUM(zero_results)*100.0/NULLIF(COUNT(*), 0), 2) as pct_sin_resultados
            FROM {$this->prefix}rcp_paginas_querys
            WHERE ts >= DATE_SUB(NOW(), INTERVAL :days2 DAY)
              AND ts < DATE_SUB(NOW(), INTERVAL :days DAY)";

            $stmtPrev1 = $this->pdo->prepare($sqlPrev1);
            $stmtPrev1->bindValue('days', $days, PDO::PARAM_INT);
            $stmtPrev1->bindValue('days2', $days * 2, PDO::PARAM_INT);
            $stmtPrev1->execute();
            $prevRow1 = $stmtPrev1->fetch();

            $sqlPrev2 = "SELECT
                COUNT(*) as clicks,
                COUNT(DISTINCT search_id) as busquedas_con_click,
                ROUND(AVG(position), 1) as pos_prom
            FROM {$this->prefix}rcp_paginas_querys_log
            WHERE ts >= DATE_SUB(NOW(), INTERVAL :days2 DAY)
              AND ts < DATE_SUB(NOW(), INTERVAL :days DAY)";

            $stmtPrev2 = $this->pdo->prepare($sqlPrev2);
            $stmtPrev2->bindValue('days', $days, PDO::PARAM_INT);
            $stmtPrev2->bindValue('days2', $days * 2, PDO::PARAM_INT);
            $stmtPrev2->execute();
            $prevRow2 = $stmtPrev2->fetch();

            // Calculate trends
            if ($prevRow1 && $prevRow2) {
                $prevBusquedas = (int) ($prevRow1['total_busquedas'] ?? 0);
                $prevSinResultados = (float) ($prevRow1['pct_sin_resultados'] ?? 0);
                $prevBusquedasConClick = (int) ($prevRow2['busquedas_con_click'] ?? 0);
                $prevCtr = $prevBusquedas > 0 ? round(($prevBusquedasConClick / $prevBusquedas) * 100, 1) : 0;
                $prevPosProm = (float) ($prevRow2['pos_prom'] ?? 0);

                // Trend = current - previous (positive = improvement for most, except pos_prom)
                if ($prevBusquedas > 0) {
                    $result['trends']['busquedas'] = round((($result['total_busquedas'] - $prevBusquedas) / $prevBusquedas) * 100, 1);
                }
                if ($prevCtr > 0) {
                    $result['trends']['ctr'] = round($result['ctr'] - $prevCtr, 1);
                }
                $result['trends']['sin_resultados'] = round($result['pct_sin_resultados'] - $prevSinResultados, 1);
                if ($prevPosProm > 0) {
                    $result['trends']['pos_prom'] = round($result['pos_prom'] - $prevPosProm, 1);
                }
            }
        } catch (PDOException $e) {
            error_log('ROI APU Metrics Repository - getKPIs error: ' . $e->getMessage());
        }

        return $result;
    }

    /**
     * Get terms with truly 0% CTR (have results but ZERO clicks globally)
     * Only shows terms where no search instance ever got a click
     *
     * @param int $days Number of days to query
     * @param int $limit Max results
     * @return array<array{q_term: string, busquedas: int, resultados: int}>
     */
    public function getCTRZero(int $days = 30, int $limit = 20): array
    {
        try {
            // Get terms with results but 0 total clicks (true 0% CTR)
            $sql = "SELECT
                    s.q_term,
                    COUNT(DISTINCT s.id) as busquedas,
                    MAX(s.total_results) as resultados,
                    COUNT(DISTINCT c.id) as clicks
                FROM {$this->prefix}rcp_paginas_querys s
                LEFT JOIN {$this->prefix}rcp_paginas_querys_log c ON s.id = c.search_id
                WHERE s.total_results > 0
                  AND s.ts >= DATE_SUB(NOW(), INTERVAL :days DAY)
                GROUP BY s.q_term
                HAVING clicks = 0 AND busquedas >= 3
                ORDER BY busquedas DESC
                LIMIT :limit";

            $stmt = $this->pdo->prepare($sql);
            $stmt->bindValue('days', $days, PDO::PARAM_INT);
            $stmt->bindValue('limit', $limit, PDO::PARAM_INT);
            $stmt->execute();

            return $stmt->fetchAll();
        } catch (PDOException $e) {
            error_log('ROI APU Metrics Repository - getCTRZero error: ' . $e->getMessage());
            return [];
        }
    }

    /**
     * Get underpositioned posts (many clicks but high position)
     *
     * @param int $days Number of days to query
     * @param int $minClicks Minimum clicks threshold
     * @param int $minPosition Minimum position threshold
     * @param int $limit Max results
     * @return array<array{post_id: int, post_title: string, clicks: int, pos_prom: float}>
     */
    public function getInfraposicionados(
        int $days = 30,
        int $minClicks = 5,
        int $minPosition = 5,
        int $limit = 20
    ): array {
        try {
            $sql = "SELECT c.post_id, p.post_title, COUNT(*) as clicks, ROUND(AVG(c.position), 1) as pos_prom
                FROM {$this->prefix}rcp_paginas_querys_log c
                JOIN {$this->prefix}posts p ON c.post_id = p.ID
                WHERE c.ts >= DATE_SUB(NOW(), INTERVAL :days DAY)
                GROUP BY c.post_id, p.post_title
                HAVING clicks >= :minClicks AND pos_prom >= :minPosition
                ORDER BY clicks DESC
                LIMIT :limit";

            $stmt = $this->pdo->prepare($sql);
            $stmt->bindValue('days', $days, PDO::PARAM_INT);
            $stmt->bindValue('minClicks', $minClicks, PDO::PARAM_INT);
            $stmt->bindValue('minPosition', $minPosition, PDO::PARAM_INT);
            $stmt->bindValue('limit', $limit, PDO::PARAM_INT);
            $stmt->execute();

            return $stmt->fetchAll();
        } catch (PDOException $e) {
            error_log('ROI APU Metrics Repository - getInfraposicionados error: ' . $e->getMessage());
            return [];
        }
    }

    // ========================================================================
    // Dashboard v2 Methods - Recomendaciones Accionables
    // ========================================================================

    /**
     * Get top search terms with metrics (paginated)
     *
     * @param int $days Number of days to query
     * @param int $limit Results per page
     * @param int $offset Pagination offset
     * @return array<array{q_term: string, busquedas: int, clicks: int, ctr: float, resultados: int}>
     */
    public function getTopSearches(int $days = 30, int $limit = 20, int $offset = 0): array
    {
        try {
            $sql = "SELECT
                s.q_term,
                COUNT(DISTINCT s.id) as busquedas,
                COUNT(DISTINCT c.id) as clicks,
                ROUND(COUNT(DISTINCT c.search_id) * 100.0 / NULLIF(COUNT(DISTINCT s.id), 0), 1) as ctr,
                MAX(s.total_results) as resultados
            FROM {$this->prefix}rcp_paginas_querys s
            LEFT JOIN {$this->prefix}rcp_paginas_querys_log c ON s.id = c.search_id
            WHERE s.ts >= DATE_SUB(NOW(), INTERVAL :days DAY)
            GROUP BY s.q_term
            ORDER BY busquedas DESC
            LIMIT :limit OFFSET :offset";

            $stmt = $this->pdo->prepare($sql);
            $stmt->bindValue('days', $days, PDO::PARAM_INT);
            $stmt->bindValue('limit', $limit, PDO::PARAM_INT);
            $stmt->bindValue('offset', $offset, PDO::PARAM_INT);
            $stmt->execute();

            return $stmt->fetchAll();
        } catch (PDOException $e) {
            error_log('ROI APU Metrics Repository - getTopSearches error: ' . $e->getMessage());
            return [];
        }
    }

    /**
     * Get top clicked posts with URL (paginated)
     *
     * @param int $days Number of days to query
     * @param int $limit Results per page
     * @param int $offset Pagination offset
     * @return array<array{post_id: int, post_title: string, post_name: string, clicks: int, busquedas_con_click: int, pos_prom: float}>
     */
    public function getTopClicks(int $days = 30, int $limit = 20, int $offset = 0): array
    {
        try {
            $sql = "SELECT
                c.post_id,
                p.post_title,
                p.post_name,
                COUNT(DISTINCT c.id) as clicks,
                COUNT(DISTINCT c.search_id) as busquedas_con_click,
                ROUND(AVG(c.position), 1) as pos_prom
            FROM {$this->prefix}rcp_paginas_querys_log c
            JOIN {$this->prefix}posts p ON c.post_id = p.ID
            WHERE c.ts >= DATE_SUB(NOW(), INTERVAL :days DAY)
            GROUP BY c.post_id, p.post_title, p.post_name
            ORDER BY clicks DESC
            LIMIT :limit OFFSET :offset";

            $stmt = $this->pdo->prepare($sql);
            $stmt->bindValue('days', $days, PDO::PARAM_INT);
            $stmt->bindValue('limit', $limit, PDO::PARAM_INT);
            $stmt->bindValue('offset', $offset, PDO::PARAM_INT);
            $stmt->execute();

            return $stmt->fetchAll();
        } catch (PDOException $e) {
            error_log('ROI APU Metrics Repository - getTopClicks error: ' . $e->getMessage());
            return [];
        }
    }

    /**
     * Get searches with zero results (paginated)
     *
     * @param int $days Number of days to query
     * @param int $limit Results per page
     * @param int $offset Pagination offset
     * @return array<array{q_term: string, frecuencia: int, ultima_busqueda: string}>
     */
    public function getZeroResults(int $days = 30, int $limit = 20, int $offset = 0): array
    {
        try {
            $sql = "SELECT
                q_term,
                COUNT(*) as frecuencia,
                MAX(ts) as ultima_busqueda
            FROM {$this->prefix}rcp_paginas_querys
            WHERE zero_results = 1
              AND ts >= DATE_SUB(NOW(), INTERVAL :days DAY)
            GROUP BY q_term
            ORDER BY frecuencia DESC
            LIMIT :limit OFFSET :offset";

            $stmt = $this->pdo->prepare($sql);
            $stmt->bindValue('days', $days, PDO::PARAM_INT);
            $stmt->bindValue('limit', $limit, PDO::PARAM_INT);
            $stmt->bindValue('offset', $offset, PDO::PARAM_INT);
            $stmt->execute();

            return $stmt->fetchAll();
        } catch (PDOException $e) {
            error_log('ROI APU Metrics Repository - getZeroResults error: ' . $e->getMessage());
            return [];
        }
    }

    /**
     * Get quick wins: terms in position 2-15 with some CTR
     * Relaxed criteria to show more actionable data
     *
     * @param int $days Number of days to query
     * @param int $limit Max results
     * @return array<array{q_term: string, busquedas: int, clicks: int, ctr: float, pos_prom: float}>
     */
    public function getQuickWins(int $days = 30, int $limit = 10): array
    {
        try {
            $sql = "SELECT
                s.q_term,
                COUNT(DISTINCT s.id) as busquedas,
                COUNT(DISTINCT c.id) as clicks,
                ROUND(COUNT(DISTINCT c.search_id) * 100.0 / NULLIF(COUNT(DISTINCT s.id), 0), 1) as ctr,
                ROUND(AVG(c.position), 1) as pos_prom
            FROM {$this->prefix}rcp_paginas_querys s
            JOIN {$this->prefix}rcp_paginas_querys_log c ON s.id = c.search_id
            WHERE s.ts >= DATE_SUB(NOW(), INTERVAL :days DAY)
            GROUP BY s.q_term
            HAVING pos_prom BETWEEN 2 AND 15
               AND ctr >= 2.0
               AND busquedas >= 2
            ORDER BY busquedas DESC
            LIMIT :limit";

            $stmt = $this->pdo->prepare($sql);
            $stmt->bindValue('days', $days, PDO::PARAM_INT);
            $stmt->bindValue('limit', $limit, PDO::PARAM_INT);
            $stmt->execute();

            return $stmt->fetchAll();
        } catch (PDOException $e) {
            error_log('ROI APU Metrics Repository - getQuickWins error: ' . $e->getMessage());
            return [];
        }
    }

    /**
     * Get star content: posts with most clicks
     *
     * @param int $days Number of days to query
     * @param int $limit Max results
     * @return array<array{post_id: int, post_title: string, post_name: string, clicks: int, busquedas_con_click: int, pos_prom: float}>
     */
    public function getContenidoEstrella(int $days = 30, int $limit = 10): array
    {
        try {
            $sql = "SELECT
                c.post_id,
                p.post_title,
                p.post_name,
                COUNT(DISTINCT c.id) as clicks,
                COUNT(DISTINCT c.search_id) as busquedas_con_click,
                ROUND(AVG(c.position), 1) as pos_prom
            FROM {$this->prefix}rcp_paginas_querys_log c
            JOIN {$this->prefix}posts p ON c.post_id = p.ID
            WHERE c.ts >= DATE_SUB(NOW(), INTERVAL :days DAY)
            GROUP BY c.post_id, p.post_title, p.post_name
            HAVING clicks >= 3
            ORDER BY clicks DESC
            LIMIT :limit";

            $stmt = $this->pdo->prepare($sql);
            $stmt->bindValue('days', $days, PDO::PARAM_INT);
            $stmt->bindValue('limit', $limit, PDO::PARAM_INT);
            $stmt->execute();

            return $stmt->fetchAll();
        } catch (PDOException $e) {
            error_log('ROI APU Metrics Repository - getContenidoEstrella error: ' . $e->getMessage());
            return [];
        }
    }

    /**
     * Get click distribution by position (positions 1-10 individually, 11+ grouped)
     *
     * @param int $days Number of days to query
     * @return array<array{posicion: string, clicks: int, porcentaje: float}>
     */
    public function getClickDistribution(int $days = 30): array
    {
        try {
            $sql = "SELECT
                CASE
                    WHEN position = 1 THEN 'Pos 1'
                    WHEN position = 2 THEN 'Pos 2'
                    WHEN position = 3 THEN 'Pos 3'
                    WHEN position = 4 THEN 'Pos 4'
                    WHEN position = 5 THEN 'Pos 5'
                    WHEN position = 6 THEN 'Pos 6'
                    WHEN position = 7 THEN 'Pos 7'
                    WHEN position = 8 THEN 'Pos 8'
                    WHEN position = 9 THEN 'Pos 9'
                    WHEN position = 10 THEN 'Pos 10'
                    ELSE 'Pos 11+'
                END as posicion,
                COUNT(*) as clicks,
                ROUND(COUNT(*) * 100.0 / NULLIF((
                    SELECT COUNT(*) FROM {$this->prefix}rcp_paginas_querys_log
                    WHERE ts >= DATE_SUB(NOW(), INTERVAL :days2 DAY)
                ), 0), 1) as porcentaje
            FROM {$this->prefix}rcp_paginas_querys_log
            WHERE ts >= DATE_SUB(NOW(), INTERVAL :days DAY)
            GROUP BY posicion
            ORDER BY MIN(position)";

            $stmt = $this->pdo->prepare($sql);
            $stmt->bindValue('days', $days, PDO::PARAM_INT);
            $stmt->bindValue('days2', $days, PDO::PARAM_INT);
            $stmt->execute();

            return $stmt->fetchAll();
        } catch (PDOException $e) {
            error_log('ROI APU Metrics Repository - getClickDistribution error: ' . $e->getMessage());
            return [];
        }
    }

    /**
     * Get decaying content: posts that lost clicks vs previous period
     * Only shows posts with significant traffic (≥5 clicks before) to avoid statistical noise
     *
     * @param int $days Number of days to query
     * @param int $limit Max results
     * @return array<array{post_id: int, post_title: string, post_name: string, clicks_actual: int, clicks_anterior: int, cambio_pct: float}>
     */
    public function getDecayContent(int $days = 30, int $limit = 10): array
    {
        try {
            $sql = "SELECT
                pa.post_id,
                p.post_title,
                p.post_name,
                COALESCE(curr.clicks_actual, 0) as clicks_actual,
                pa.clicks_anterior,
                ROUND((COALESCE(curr.clicks_actual, 0) - pa.clicks_anterior) * 100.0 / pa.clicks_anterior, 1) as cambio_pct
            FROM (
                SELECT post_id, COUNT(*) as clicks_anterior
                FROM {$this->prefix}rcp_paginas_querys_log
                WHERE ts >= DATE_SUB(NOW(), INTERVAL :days2 DAY)
                  AND ts < DATE_SUB(NOW(), INTERVAL :days DAY)
                GROUP BY post_id
            ) pa
            LEFT JOIN (
                SELECT post_id, COUNT(*) as clicks_actual
                FROM {$this->prefix}rcp_paginas_querys_log
                WHERE ts >= DATE_SUB(NOW(), INTERVAL :days3 DAY)
                GROUP BY post_id
            ) curr ON pa.post_id = curr.post_id
            JOIN {$this->prefix}posts p ON pa.post_id = p.ID
            WHERE pa.clicks_anterior >= 5
              AND (COALESCE(curr.clicks_actual, 0) - pa.clicks_anterior) * 100.0 / pa.clicks_anterior <= -20
            ORDER BY cambio_pct ASC
            LIMIT :limit";

            $stmt = $this->pdo->prepare($sql);
            $stmt->bindValue('days', $days, PDO::PARAM_INT);
            $stmt->bindValue('days2', $days * 2, PDO::PARAM_INT);
            $stmt->bindValue('days3', $days, PDO::PARAM_INT);
            $stmt->bindValue('limit', $limit, PDO::PARAM_INT);
            $stmt->execute();

            return $stmt->fetchAll();
        } catch (PDOException $e) {
            error_log('ROI APU Metrics Repository - getDecayContent error: ' . $e->getMessage());
            return [];
        }
    }

    /**
     * Get total counts for pagination
     *
     * @param int $days Number of days to query
     * @return array{total_searches: int, total_clicks: int, total_zero_results: int}
     */
    public function getTotalCounts(int $days = 30): array
    {
        $result = [
            'total_searches' => 0,
            'total_clicks' => 0,
            'total_zero_results' => 0,
        ];

        try {
            // Count distinct search terms
            $sql1 = "SELECT COUNT(DISTINCT q_term) as total
                FROM {$this->prefix}rcp_paginas_querys
                WHERE ts >= DATE_SUB(NOW(), INTERVAL :days DAY)";
            $stmt1 = $this->pdo->prepare($sql1);
            $stmt1->execute(['days' => $days]);
            $result['total_searches'] = (int) $stmt1->fetchColumn();

            // Count distinct clicked posts
            $sql2 = "SELECT COUNT(DISTINCT post_id) as total
                FROM {$this->prefix}rcp_paginas_querys_log
                WHERE ts >= DATE_SUB(NOW(), INTERVAL :days DAY)";
            $stmt2 = $this->pdo->prepare($sql2);
            $stmt2->execute(['days' => $days]);
            $result['total_clicks'] = (int) $stmt2->fetchColumn();

            // Count distinct zero result terms
            $sql3 = "SELECT COUNT(DISTINCT q_term) as total
                FROM {$this->prefix}rcp_paginas_querys
                WHERE zero_results = 1
                  AND ts >= DATE_SUB(NOW(), INTERVAL :days DAY)";
            $stmt3 = $this->pdo->prepare($sql3);
            $stmt3->execute(['days' => $days]);
            $result['total_zero_results'] = (int) $stmt3->fetchColumn();
        } catch (PDOException $e) {
            error_log('ROI APU Metrics Repository - getTotalCounts error: ' . $e->getMessage());
        }

        return $result;
    }
}