<?php

namespace AcademicCrew\Shortcodes;

use AcademicCrew\Core\Loader;
use AcademicCrew\Courses\AcademicYearCalculator;
use AcademicCrew\Members\RoleRegistry;

/**
 * [acc_stat_counters]
 *
 * A row of big-number counters — published courses / projects / people plus
 * any number of custom, manually-entered ones — with an optional count-up
 * animation that fires when the widget scrolls into view (skipped for
 * `prefers-reduced-motion`). Rounding is configured per counter.
 *
 * Attributes:
 *   show="courses,projects,people"   which built-in counters, in this order;
 *                                    "none" shows none of them (custom only)
 *   animate="yes"                    yes | no
 *   columns="3"                      grid columns on desktop (1–4)
 *   duration="2000"                  count-up duration in ms
 *   courses_label / projects_label / people_label   override the labels
 *
 *   courses="all"          all | current   (current = latest academic year only)
 *   projects="all"         all | active | past
 *   members_exclude=""     comma list of role slugs to leave out of the people
 *                          count; the token "former" expands to every former-*
 *                          role plus "alumni"
 *
 *   num_size=""            CSS size for the big number (e.g. "3rem", "48px")
 *   label_size=""          CSS size for the label under it (e.g. "12px")
 *   num_color=""           CSS color for the big number (e.g. "#c41230",
 *                          "rebeccapurple", "var(--acc-primary)")
 *   label_color=""         CSS color for the label underneath
 *
 *   round="0"              default rounding for every counter: 0 = exact,
 *                          otherwise round the count DOWN to the nearest
 *                          multiple of this (round="10": 48 → 40)
 *   suffix="+"             default suffix appended after a rounded number
 *                          ("40+"); ignored when that counter isn't rounded
 *   courses_round / courses_suffix,
 *   projects_round / projects_suffix,
 *   people_round   / people_suffix     per-counter overrides of the two above
 *
 *   custom=""               extra hand-entered counters, one per line:
 *                           "Label | Value | Round | Suffix" — Round and
 *                           Suffix are optional and fall back to round/suffix
 *                           above, e.g.:
 *                             Patents | 34
 *                             Awards | 128 | 10 | +
 *
 * Block alias: academiccrew/stat-counters
 */
class StatCountersShortcode {

    private const METRICS   = [ 'courses', 'projects', 'people' ];
    private const MAX_CUSTOM = 12;

    public function register( Loader $loader ): void {
        add_shortcode( 'acc_stat_counters', [ $this, 'render' ] );
    }

    /**
     * @param array<string,string> $atts
     */
    public function render( $atts ): string {
        $atts = shortcode_atts( [
            'show'            => 'courses,projects,people',
            'animate'         => 'yes',
            'columns'         => 3,
            'duration'        => 2000,
            'courses_label'   => '',
            'projects_label'  => '',
            'people_label'    => '',
            'courses'         => 'all',
            'projects'        => 'all',
            'members_exclude' => '',
            'num_size'        => '',
            'label_size'      => '',
            'num_color'       => '',
            'label_color'     => '',
            'round'           => 0,
            'suffix'          => '+',
            'courses_round'   => '',
            'courses_suffix'  => '',
            'projects_round'  => '',
            'projects_suffix' => '',
            'people_round'    => '',
            'people_suffix'   => '',
            'custom'          => '',
        ], (array) $atts, 'acc_stat_counters' );

        $courses_scope  = in_array( strtolower( (string) $atts['courses'] ), [ 'all', 'current' ], true )
            ? strtolower( (string) $atts['courses'] ) : 'all';
        $projects_scope = in_array( strtolower( (string) $atts['projects'] ), [ 'all', 'active', 'past' ], true )
            ? strtolower( (string) $atts['projects'] ) : 'all';
        $exclude_roles  = $this->parse_excluded_roles( (string) $atts['members_exclude'] );

        $show_raw = trim( strtolower( (string) $atts['show'] ) );
        if ( 'none' === $show_raw ) {
            $wanted = [];
        } else {
            $wanted = array_values( array_unique( array_filter(
                array_map( 'trim', explode( ',', $show_raw ) ),
                static fn( $m ) => in_array( $m, self::METRICS, true )
            ) ) );
            if ( ! $wanted ) {
                $wanted = self::METRICS;
            }
        }

        $animate    = 'no' !== strtolower( (string) $atts['animate'] );
        $columns    = max( 1, min( 4, (int) $atts['columns'] ) );
        $duration   = max( 200, min( 10000, (int) $atts['duration'] ) );
        $num_size    = $this->sanitize_css_size( (string) $atts['num_size'] );
        $label_size  = $this->sanitize_css_size( (string) $atts['label_size'] );
        $num_color   = $this->sanitize_css_color( (string) $atts['num_color'] );
        $label_color = $this->sanitize_css_color( (string) $atts['label_color'] );
        $def_round  = max( 0, min( 100000, (int) $atts['round'] ) );
        $def_suffix = mb_substr( (string) $atts['suffix'], 0, 8 );

        $labels = [
            'courses'  => $atts['courses_label']  ?: __( 'Courses', 'academiccrew' ),
            'projects' => $atts['projects_label'] ?: __( 'Projects', 'academiccrew' ),
            'people'   => $atts['people_label']   ?: __( 'People', 'academiccrew' ),
        ];
        $counts = [
            'courses'  => $this->count_courses( $courses_scope ),
            'projects' => $this->count_projects( $projects_scope ),
            'people'   => $this->count_members( $exclude_roles ),
        ];

        // Build one flat list of counters — built-ins the caller asked for,
        // then the hand-entered custom ones — each with its own round/suffix
        // (falling back to the round="" / suffix="" defaults above).
        $counters = [];
        foreach ( $wanted as $metric ) {
            [ $round, $suffix ] = $this->resolve_round(
                (string) $atts[ $metric . '_round' ],
                (string) $atts[ $metric . '_suffix' ],
                $def_round,
                $def_suffix
            );
            $counters[] = [
                'key'    => $metric,
                'label'  => $labels[ $metric ],
                'raw'    => (int) $counts[ $metric ],
                'round'  => $round,
                'suffix' => $suffix,
            ];
        }
        array_push( $counters, ...$this->parse_custom( (string) $atts['custom'], $def_round, $def_suffix ) );

        if ( ! $counters ) {
            return '';
        }

        $wrap_style = '--acc-stats-cols:' . $columns;
        if ( '' !== $num_size ) {
            $wrap_style .= ';--acc-stat-num-size:' . $num_size;
        }
        if ( '' !== $label_size ) {
            $wrap_style .= ';--acc-stat-label-size:' . $label_size;
        }
        if ( '' !== $num_color ) {
            $wrap_style .= ';--acc-stat-num-color:' . $num_color;
        }
        if ( '' !== $label_color ) {
            $wrap_style .= ';--acc-stat-label-color:' . $label_color;
        }

        ob_start();
        ?>
        <div class="acc-stats" style="<?php echo esc_attr( $wrap_style ); ?>">
            <?php foreach ( $counters as $c ) :
                if ( $c['round'] > 0 && $c['raw'] >= $c['round'] ) {
                    $value       = intdiv( $c['raw'], $c['round'] ) * $c['round'];
                    $with_suffix = $c['suffix'];
                } else {
                    $value       = $c['raw'];
                    $with_suffix = '';
                }
                ?>
                <div class="acc-stat acc-stat--<?php echo esc_attr( $c['key'] ); ?>">
                    <span class="acc-stat-num"
                          data-acc-count="<?php echo esc_attr( (string) $value ); ?>"
                          data-acc-suffix="<?php echo esc_attr( $with_suffix ); ?>"
                          <?php echo $animate ? 'data-acc-animate="1" data-acc-duration="' . esc_attr( (string) $duration ) . '"' : ''; ?>><?php
                        echo esc_html( $animate ? '0' . $with_suffix : number_format_i18n( $value ) . $with_suffix );
                    ?></span>
                    <span class="acc-stat-label"><?php echo esc_html( $c['label'] ); ?></span>
                </div>
            <?php endforeach; ?>
        </div>
        <?php
        $this->enqueue_assets_once();

        return (string) ob_get_clean();
    }

    /**
     * A per-counter round/suffix override, falling back to the widget-wide
     * default when left blank ("").
     *
     * @return array{0:int,1:string}
     */
    private function resolve_round( string $round_override, string $suffix_override, int $default_round, string $default_suffix ): array {
        $round  = '' !== trim( $round_override ) ? max( 0, min( 100000, (int) $round_override ) ) : $default_round;
        $suffix = '' !== $suffix_override ? mb_substr( $suffix_override, 0, 8 ) : $default_suffix;
        return [ $round, $suffix ];
    }

    /**
     * Parses the "custom" textarea: one counter per line,
     * "Label | Value | Round | Suffix" (Round/Suffix optional).
     *
     * @return array<int,array{key:string,label:string,raw:int,round:int,suffix:string}>
     */
    private function parse_custom( string $raw, int $default_round, string $default_suffix ): array {
        $out = [];
        $n   = 0;
        foreach ( preg_split( '/\r\n|\r|\n/', $raw ) as $line ) {
            $line = trim( $line );
            if ( '' === $line || $n >= self::MAX_CUSTOM ) {
                continue;
            }
            $parts = array_map( 'trim', explode( '|', $line ) );
            $label = sanitize_text_field( $parts[0] ?? '' );
            if ( '' === $label ) {
                continue;
            }
            $n++;
            [ $round, $suffix ] = $this->resolve_round(
                $parts[2] ?? '',
                $parts[3] ?? '',
                $default_round,
                $default_suffix
            );
            $out[] = [
                'key'    => 'custom-' . $n,
                'label'  => $label,
                'raw'    => max( 0, (int) preg_replace( '/[^0-9-]/', '', $parts[1] ?? '0' ) ),
                'round'  => $round,
                'suffix' => $suffix,
            ];
        }
        return $out;
    }

    /**
     * Allow a CSS length / clamp() expression only — digits, units, and the
     * handful of characters `clamp()`/`calc()` need. Anything else → ''.
     */
    private function sanitize_css_size( string $raw ): string {
        $raw = trim( $raw );
        if ( '' === $raw || strlen( $raw ) > 60 ) {
            return '';
        }
        return preg_match( '/^[0-9a-z.,%()\s\/*+-]+$/i', $raw ) ? $raw : '';
    }

    /**
     * Allow a CSS color value only — hex, named colors, rgb()/rgba()/hsl(),
     * or a var() reference. Anything else (no ':' means no javascript: URLs
     * can sneak in) → ''.
     */
    private function sanitize_css_color( string $raw ): string {
        $raw = trim( $raw );
        if ( '' === $raw || strlen( $raw ) > 60 ) {
            return '';
        }
        return preg_match( '/^[#0-9a-z.,%()\s-]+$/i', $raw ) ? $raw : '';
    }

    /** @return int[] published post IDs of a type (unfiltered). */
    private function ids( string $post_type ): array {
        return get_posts( [
            'post_type'      => $post_type,
            'post_status'    => 'publish',
            'posts_per_page' => -1,
            'fields'         => 'ids',
            'no_found_rows'  => true,
            'suppress_filters' => true,
        ] );
    }

    /** courses="all" | "current" (only the latest academic year). */
    private function count_courses( string $scope ): int {
        if ( 'current' !== $scope ) {
            return (int) ( wp_count_posts( 'academiccrew_course' )->publish ?? 0 );
        }
        $current_ay = ( new AcademicYearCalculator() )->calculate( 1 );
        return count( get_posts( [
            'post_type'      => 'academiccrew_course',
            'post_status'    => 'publish',
            'posts_per_page' => -1,
            'fields'         => 'ids',
            'no_found_rows'  => true,
            'meta_query'     => [ [
                'key'     => '_acc_academic_year',
                'value'   => $current_ay,
                'compare' => '>=',
                'type'    => 'NUMERIC',
            ] ],
        ] ) );
    }

    /** projects="all" | "active" (ongoing) | "past" (completed). */
    private function count_projects( string $scope ): int {
        if ( 'all' === $scope ) {
            return (int) ( wp_count_posts( 'acc_collaboration' )->publish ?? 0 );
        }
        $today = current_time( 'Y-m-d' );
        $n     = 0;
        foreach ( $this->ids( 'acc_collaboration' ) as $id ) {
            $end       = (string) get_post_meta( (int) $id, '_acc_end_date', true );
            $completed = '' !== $end && $end < $today;
            if ( ( 'past' === $scope ) === $completed ) {
                $n++;
            }
        }
        return $n;
    }

    /** People count, minus any excluded role slugs. */
    private function count_members( array $exclude_roles ): int {
        if ( ! $exclude_roles ) {
            return (int) ( wp_count_posts( 'academiccrew_member' )->publish ?? 0 );
        }
        $n = 0;
        foreach ( $this->ids( 'academiccrew_member' ) as $id ) {
            $role = (string) get_post_meta( (int) $id, '_acc_member_role', true ) ?: 'collaborator';
            if ( ! in_array( $role, $exclude_roles, true ) ) {
                $n++;
            }
        }
        return $n;
    }

    /**
     * "phd-student, former" → ['phd-student', 'former-professor', …, 'alumni'].
     * Unknown slugs are dropped.
     *
     * @return string[]
     */
    private function parse_excluded_roles( string $raw ): array {
        $tokens = array_filter( array_map( 'trim', explode( ',', strtolower( $raw ) ) ) );
        if ( ! $tokens ) {
            return [];
        }
        $valid = RoleRegistry::keys();
        $out   = [];
        foreach ( $tokens as $token ) {
            if ( 'former' === $token ) {
                foreach ( $valid as $key ) {
                    if ( str_starts_with( $key, 'former-' ) || 'alumni' === $key ) {
                        $out[] = $key;
                    }
                }
            } elseif ( in_array( $token, $valid, true ) ) {
                $out[] = $token;
            }
        }
        return array_values( array_unique( $out ) );
    }

    /**
     * Enqueues the inline CSS + count-up JS, at most once per request.
     */
    private function enqueue_assets_once(): void {
        static $done = false;
        if ( $done ) {
            return;
        }
        $done = true;

        $css = '.acc-stats{display:grid;grid-template-columns:repeat(var(--acc-stats-cols,3),1fr);gap:24px;margin:1.5rem 0;text-align:center}'
            . '.acc-stat{display:flex;flex-direction:column;gap:6px;padding:12px 8px}'
            . '.acc-stat-num{font-family:var(--acc-font-display,"Roboto Slab",Georgia,serif);font-weight:800;font-size:var(--acc-stat-num-size,clamp(2.4rem,5vw,3.6rem));line-height:1;color:var(--acc-stat-num-color,var(--acc-primary,#0d2340));font-variant-numeric:tabular-nums}'
            . '.acc-stat-label{font-family:var(--acc-font-mono,monospace);font-size:var(--acc-stat-label-size,11px);letter-spacing:.16em;text-transform:uppercase;color:var(--acc-stat-label-color,var(--acc-muted,#8893a6))}'
            . '@media(max-width:600px){.acc-stats{grid-template-columns:1fr;gap:14px}}'
            . '@media(prefers-reduced-motion:reduce){.acc-stat-num{transition:none}}';

        $js = "(function(){"
            . "if(window.__accStatsInit)return;window.__accStatsInit=1;"
            . "var reduce=window.matchMedia&&window.matchMedia('(prefers-reduced-motion: reduce)').matches;"
            . "function fmt(n){try{return n.toLocaleString();}catch(e){return String(n);}}"
            . "function animate(el){"
            . "var target=parseInt(el.getAttribute('data-acc-count'),10)||0;"
            . "var sfx=el.getAttribute('data-acc-suffix')||'';"
            . "if(reduce||!el.hasAttribute('data-acc-animate')){el.textContent=fmt(target)+sfx;return;}"
            . "var dur=parseInt(el.getAttribute('data-acc-duration'),10)||2000,start=null;"
            . "function step(ts){"
            . "if(start===null)start=ts;"
            . "var p=Math.min((ts-start)/dur,1),eased=1-Math.pow(1-p,3);"
            . "el.textContent=fmt(Math.round(eased*target))+sfx;"
            . "if(p<1)requestAnimationFrame(step);else el.textContent=fmt(target)+sfx;"
            . "}"
            . "requestAnimationFrame(step);"
            . "}"
            . "function run(){"
            . "var nums=document.querySelectorAll('.acc-stat-num[data-acc-count]');"
            . "if(!nums.length)return;"
            . "if(!('IntersectionObserver' in window)){Array.prototype.forEach.call(nums,animate);return;}"
            . "var io=new IntersectionObserver(function(entries){"
            . "entries.forEach(function(e){if(e.isIntersecting){animate(e.target);io.unobserve(e.target);}});"
            . "},{threshold:0.4});"
            . "Array.prototype.forEach.call(nums,function(n){io.observe(n);});"
            . "}"
            . "if(document.readyState!=='loading')run();"
            . "else document.addEventListener('DOMContentLoaded',run);"
            . "}());";

        wp_register_style( 'acc-stat-counters', false, [], ACADEMICCREW_VERSION );
        wp_add_inline_style( 'acc-stat-counters', $css );
        wp_enqueue_style( 'acc-stat-counters' );

        wp_register_script( 'acc-stat-counters', '', [], ACADEMICCREW_VERSION, true );
        wp_add_inline_script( 'acc-stat-counters', $js );
        wp_enqueue_script( 'acc-stat-counters' );
    }
}