<?php
/*
 * Part of the VastuIQ plugin: the Vastu scoring engine, the same rules VastuIQ.com uses.
 * License: GPLv2 or later.
 */
/**
 * VastuIQ Home Report Engine — main entrance pada (32-pada method)
 *
 * Same method, numbers and wording as the Pada Calculator and the Main Door
 * Vastu Checker: each wall is split into 8 padas (N1–N8, E1–E8, S1–S8, W1–W8),
 * pada 1 starts at the corner listed first in wall_order, and
 *   position score = round(dir_base×0.50 + zone_score×0.35 + position_assessment×0.15).
 * Settings are read from data/main-door-rules.json, the same file VastuIQ.com uses.
 */

namespace VastuIQWP\Engine;

defined( 'ABSPATH' ) || exit;

final class EntrancePada
{
    private const FALLBACK = [
        'wall_order' => ['North' => ['NW corner', 'NE corner'], 'East' => ['NE corner', 'SE corner'],
                         'South' => ['SE corner', 'SW corner'], 'West' => ['SW corner', 'NW corner']],
        'zone_by_index' => ['Transitional', 'Supportive', 'Balanced', 'Primary', 'Primary', 'Balanced', 'Supportive', 'Transitional'],
        'zone_score' => ['Transitional' => 52, 'Supportive' => 70, 'Balanced' => 85, 'Primary' => 92],
        'zone_rating' => ['Primary' => 'Excellent', 'Balanced' => 'Favourable', 'Supportive' => 'Neutral', 'Transitional' => 'Needs attention'],
        'dir_base' => ['North' => 90, 'East' => 88, 'South' => 55, 'West' => 65],
    ];
    private const PREFIX = ['North' => 'N', 'East' => 'E', 'South' => 'S', 'West' => 'W'];

    private array $P;
    private ?array $db = null;

    public function __construct()
    {
        $rules = json_decode(is_readable(dirname(__DIR__) . '/data/main-door-rules.json') ? (string)file_get_contents(dirname(__DIR__) . '/data/main-door-rules.json') : '', true); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents -- reads a file bundled with the plugin.
        $this->P = (is_array($rules['position'] ?? null) ? $rules['position'] : []) + self::FALLBACK;
        $this->db = null; // door-position text is not used by the plugin
    }

    /** Score for a wall direction and a position along it (0–100 % from the first corner). */
    public function score(string $wall, float $pct): array
    {
        $pct = max(0.0, min(99.999, $pct));
        $idx = (int)floor($pct / 12.5);
        $zone = $this->P['zone_by_index'][$idx];
        $within = fmod($pct, 12.5) / 12.5;
        $assess = (int)round(100 - abs($within - 0.5) * 2 * 45);
        $s = (int)round($this->P['dir_base'][$wall] * 0.5 + $this->P['zone_score'][$zone] * 0.35 + $assess * 0.15);
        return ['pada' => self::PREFIX[$wall] . ($idx + 1), 'index' => $idx, 'zone' => $zone,
                'zone_rating' => $this->P['zone_rating'][$zone] ?? '', 'score' => $s];
    }

    /**
     * Pada of the entrance from plan geometry.
     * $outlineLocal: house outline in the wall-aligned frame (x right, y down, centre at 0,0, aspect-corrected)
     * $doorLocal: the door in the same frame. $toTrue: callable(local direction angle in image terms) → true bearing.
     */
    public function fromPlan(array $centre, array $outline, array $door, float $aspect, float $wallRotImg, float $trueNorthImg): ?array
    {
        if (count($outline) < 3) return null;
        $rot = deg2rad(-$wallRotImg);
        $toLocal = function (array $p) use ($rot, $aspect, $centre) {
            $x = ($p[0] - $centre[0]) * $aspect; $y = $p[1] - $centre[1];
            return [$x * cos($rot) - $y * sin($rot), $x * sin($rot) + $y * cos($rot)];
        };
        $o = array_map($toLocal, $outline);
        [$minX, $minY, $maxX, $maxY] = Orientation::bbox($o);
        [$dx, $dy] = $toLocal($door);

        // the four walls of the (wall-aligned) footprint: [distance to door, outward normal in local frame, start, end]
        $walls = [
            ['d' => abs($dy - $minY), 'n' => [0, -1], 'a' => [$minX, $minY], 'b' => [$maxX, $minY]],
            ['d' => abs($dx - $maxX), 'n' => [1, 0],  'a' => [$maxX, $minY], 'b' => [$maxX, $maxY]],
            ['d' => abs($dy - $maxY), 'n' => [0, 1],  'a' => [$maxX, $maxY], 'b' => [$minX, $maxY]],
            ['d' => abs($dx - $minX), 'n' => [-1, 0], 'a' => [$minX, $maxY], 'b' => [$minX, $minY]],
        ];
        usort($walls, fn($p, $q) => $p['d'] <=> $q['d']);
        $w = $walls[0];

        // local direction → image bearing → true bearing
        $localToTrue = function (array $v) use ($wallRotImg, $trueNorthImg) {
            $imgBearing = rad2deg(atan2($v[0], -$v[1])) + $wallRotImg;
            return Orientation::wrap($imgBearing - $trueNorthImg);
        };
        $normal = $localToTrue($w['n']);
        $cardinals = ['North' => 0, 'East' => 90, 'South' => 180, 'West' => 270];
        $wall = 'North'; $off = 999;
        foreach ($cardinals as $name => $deg) {
            $d = abs(fmod($normal - $deg + 540, 360) - 180);
            if ($d < $off) { $off = $d; $wall = $name; }
        }

        // pada 1 is at the end of the wall that lies toward (facing − 90°)
        $len = hypot($w['b'][0] - $w['a'][0], $w['b'][1] - $w['a'][1]);
        if ($len < 1e-6) return null;
        $u = [($w['b'][0] - $w['a'][0]) / $len, ($w['b'][1] - $w['a'][1]) / $len];
        $alongTrue = $localToTrue($u);                                      // direction from a to b
        $wantStart = Orientation::wrap($cardinals[$wall] - 90);             // first corner side
        $dAB = abs(fmod($alongTrue - $wantStart + 540, 360) - 180);         // small → b is the start
        $t = (($dx - $w['a'][0]) * $u[0] + ($dy - $w['a'][1]) * $u[1]) / $len;
        $t = max(0.0, min(1.0, $t));
        $pct = ($dAB < 90 ? (1 - $t) : $t) * 100;

        $s = $this->score($wall, $pct);
        $better = [];
        for ($i = 0; $i < 8; $i++) {
            $alt = $this->score($wall, $i * 12.5 + 6.25);
            if ($alt['score'] > $s['score']) $better[] = $alt + ['from_pct' => $i * 12.5, 'to_pct' => ($i + 1) * 12.5];
        }
        usort($better, fn($p, $q) => $q['score'] <=> $p['score']);

        $entry = $this->db[$s['pada']] ?? null;
        return $s + [
            'wall' => $wall,
            'facing_bearing' => round($normal, 1),
            'angled' => $off >= 15,   // wall well off the compass: nearest direction used
            'offset' => round($off, 1),
            'position_pct' => round($pct, 1),
            'corners' => $this->P['wall_order'][$wall],
            'better' => array_slice($better, 0, 3),
            'interpretation' => $entry['interpretation'] ?? null,
            'strengths' => $entry['strengths'] ?? [],
            'cautions' => $entry['cautions'] ?? [],
        ];
    }
}