<?php

if (!defined('ABSPATH')) {
    exit;
}

class AdGhost_Zone_Inferrer {

    const NAME_TOKENS = [
        'interstitial' => 'out-of-page',
        'reward'       => 'out-of-page',
        'skyscraper'   => 'sidebar',
        'leaderboard'  => 'header',
        'incontent'    => 'content',
        'sidebar'      => 'sidebar',
        'anchor'       => 'anchor',
        'sticky'       => 'anchor',
        'header'       => 'header',
        'footer'       => 'footer',
        'bottom'       => 'footer',
        'article'      => 'content',
        'content'      => 'content',
        'rail'         => 'sidebar',
        'top'          => 'header',
    ];

    const NAME_FORMATS = [
        'leaderboard'  => 'leaderboard',
        'skyscraper'   => 'skyscraper',
        'anchor'       => 'anchor',
        'sticky'       => 'anchor',
        'interstitial' => 'interstitial',
        'reward'       => 'reward',
        'mpu'          => 'mpu',
        'rectangle'    => 'mpu',
    ];

    const SHAPE_ZONES = [
        'leaderboard' => 'header',
        'skyscraper'  => 'sidebar',
        'mpu'         => 'content',
        'anchor'      => 'anchor',
        'special'     => 'out-of-page',
    ];

    const ZONE_POSITIONS = [
        'header'      => 'header',
        'footer'      => 'footer',
        'sidebar'     => 'sidebar',
        'content'     => 'incontent',
        'anchor'      => 'anchor',
        'out-of-page' => 'interstitial',
    ];

    public static function infer(array $unit) {
        $name  = strtolower((string) ($unit['name'] ?? '') . ' ' . (string) ($unit['id'] ?? ''));
        $sizes = (string) ($unit['sizes'] ?? '');

        $from_name = self::from_name($name);
        $from_size = self::from_size($sizes);

        if ($from_size !== null && $from_name !== null && $from_size['zone'] !== $from_name['zone']) {
            return self::result(
                $from_size['zone'],
                $from_name['format'] ?: $from_size['format'],
                sprintf(
                    'Name suggests %s but a %s creative only fits %s — size decides the zone',
                    $from_name['zone'],
                    $from_size['shape'],
                    $from_size['zone']
                )
            );
        }

        if ($from_size !== null) {
            $format = ($from_name !== null && $from_name['format']) ? $from_name['format'] : $from_size['format'];
            return self::result(
                $from_size['zone'],
                $format,
                sprintf('%s creative (%s) belongs in %s', $from_size['shape'], $from_size['size'], $from_size['zone'])
            );
        }

        if ($from_name !== null) {
            return self::result(
                $from_name['zone'],
                $from_name['format'] ?: 'unknown',
                sprintf('Name contains "%s"', $from_name['token'])
            );
        }

        return [
            'zone'     => 'content',
            'format'   => 'unknown',
            'position' => 'incontent',
            'reason'   => 'Nothing in the name or size indicates a zone — defaulting to in-content',
            'inferred' => false,
        ];
    }

    public static function position(array $unit) {
        $result = self::infer($unit);
        return $result['position'];
    }

    private static function result($zone, $format, $reason) {
        return [
            'zone'     => $zone,
            'format'   => $format,
            'position' => self::ZONE_POSITIONS[$zone] ?? 'incontent',
            'reason'   => $reason,
            'inferred' => true,
        ];
    }

    private static function from_name($name) {
        if ($name === '') {
            return null;
        }
        foreach (self::NAME_TOKENS as $token => $zone) {

            $found = in_array($token, ['top', 'rail'], true)
                ? preg_match('/(?<![a-z])' . $token . '(?![a-z])/', $name)
                : strpos($name, $token) !== false;
            if ($found) {
                return [
                    'zone'   => $zone,
                    'format' => self::NAME_FORMATS[$token] ?? '',
                    'token'  => $token,
                ];
            }
        }
        return null;
    }

    private static function from_size($sizes_str) {
        if (trim($sizes_str) === '') {
            return null;
        }

        $first = trim(preg_split('/[;,]/', $sizes_str)[0]);
        $flat  = strtolower(str_replace([' ', '_', '-'], '', $first));

        if ($flat === 'outofpage' || $flat === 'fluid' || $flat === 'native') {
            return self::shape('special', $first);
        }

        if (!preg_match('/^(\d+)x(\d+)$/i', $flat, $m)) {
            return null;
        }
        $w = (int) $m[1];
        $h = (int) $m[2];
        if ($w <= 0 || $h <= 0) {
            return null;
        }

        if ($w === 320 && ($h === 50 || $h === 100)) {
            return self::shape('anchor', $first);
        }

        if ($h > 0 && ($w / $h) >= 4 && $w >= 728) {
            return self::shape('leaderboard', $first);
        }

        if ($h >= ($w * 2) && $h >= 600) {
            return self::shape('skyscraper', $first);
        }

        if ($w >= 250 && $w <= 350 && $h >= 250 && $h <= 350) {
            return self::shape('mpu', $first);
        }

        return null;
    }

    private static function shape($shape, $size) {
        return [
            'zone'   => self::SHAPE_ZONES[$shape],
            'format' => $shape,
            'shape'  => $shape,
            'size'   => $size,
        ];
    }
}