<?php

namespace App\Game;

use App\Engine\Art;

/** The status bar (st_stuff.c): 320 x 32 palette pixels, redrawn each frame from the player's state. */
final class Hud
{
    public const HEIGHT = 32;

    public function __construct(private Art $art)
    {
    }

    public function bar(World $world): string
    {
        $p = $world->player;
        $hud = $this->art->hud;
        $bar = $hud['STBAR']['px'];
        $w = Weapons::LIST[$p->weapon];
        if ($w['ammo'] !== null) {
            $this->big($bar, 50, 5, (string)$p->ammo[$w['ammo']]);
        }
        $this->big($bar, 110, 5, $p->health . '%');
        $this->big($bar, 246, 5, $p->armor . '%');
        // owned weapons 2..5: yellow when owned
        foreach ([2, 3, 4, 5] as $k => $n) {
            $tone = !empty($p->weapons[$n]) ? 'Y' : 'G';
            $this->blit($bar, $hud["S$tone$n"], 123 + ($k % 2) * 16, 7 + intdiv($k, 2) * 12);
        }
        // the helmet: cracks with damage, red visor when just hurt
        $level = $p->health >= 80 ? 0 : ($p->health >= 60 ? 1 : ($p->health >= 40 ? 2 : ($p->health >= 20 ? 3 : 4)));
        $face = $hud['FACE' . $level . ($p->damagecount > 0 || $p->dead ? 'H' : '')];
        $this->blit($bar, $face, 155, 3);
        // keys
        foreach (['red' => 'R', 'blue' => 'B', 'yellow' => 'Y'] as $k => $c) {
            if (!empty($p->keys[$k])) {
                $this->blit($bar, $hud["KEY$c"], 253, 5 + ['R' => 0, 'B' => 8, 'Y' => 16][$c]);
            }
        }
        // stock of each ammunition
        foreach (['bullets', 'shells', 'cells'] as $i => $a) {
            $this->small($bar, 314, 5 + $i * 8, $p->ammo[$a] . '/' . Player::AMMO_MAX[$a]);
        }
        return $bar;
    }

    /** Big red digits, right-aligned at $right. */
    private function big(string &$bar, int $right, int $y, string $text): void
    {
        $x = $right - strlen($text) * 14;
        foreach (str_split($text) as $ch) {
            $pic = $this->art->hud['BIG' . $ch] ?? null;
            if ($pic !== null) {
                $this->blit($bar, $pic, $x, $y);
            }
            $x += 14;
        }
    }

    private function small(string &$bar, int $right, int $y, string $text): void
    {
        $x = $right - strlen($text) * 4;
        foreach (str_split($text) as $ch) {
            if ($ch === '/') {
                $bar[($y + 4) * 320 + $x] = chr(8);
                $bar[($y + 2) * 320 + $x + 1] = chr(8);
                $bar[$y * 320 + $x + 2] = chr(8);
            } elseif (isset($this->art->hud['SY' . $ch])) {
                $this->blit($bar, $this->art->hud['SY' . $ch], $x, $y);
            }
            $x += 4;
        }
    }

    private function blit(string &$bar, array $pic, int $x, int $y): void
    {
        $w = $pic['w'];
        for ($j = 0; $j < $pic['h']; $j++) {
            $row = substr($pic['px'], $j * $w, $w);
            $o = ($y + $j) * 320 + $x;
            for ($i = 0; $i < $w; $i++) {
                if ($row[$i] !== "\xFF") {
                    $bar[$o + $i] = $row[$i];
                }
            }
        }
    }
}