<?php

namespace App\Gfx;

/** Build-time-free procedural wall posters, shared by native OpenGL and WASM/WebGL. */
final class PosterFactory
{
    public const ATLAS_COLS = 4;
    public const ATLAS_ROWS = 4;
    public const TILE_W = 200;
    public const TILE_H = 290;

    /**
     * 4x4 atlas. Four cells keep the banal "VOTRE PUB ICI" gag; the other
     * twelve are generated by the DeepSeek MinitelRosePoster supplied for the game.
     */
    public static function advert(): \GdImage
    {
        $atlas = imagecreatetruecolor(self::ATLAS_COLS * self::TILE_W, self::ATLAS_ROWS * self::TILE_H);
        imagealphablending($atlas, true);
        imagesavealpha($atlas, true);
        imagefill($atlas, 0, 0, imagecolorallocate($atlas, 16, 8, 24));

        $rose = new MinitelRosePoster();
        for ($i = 0; $i < self::ATLAS_COLS * self::ATLAS_ROWS; $i++) {
            if ($i % 4 === 0) {
                $tile = self::advertTile($i);
            } else {
                $tile = $rose->generate(361500 + $i * 97);
                self::zoomPixelatePortrait($tile);
            }
            $x = ($i % self::ATLAS_COLS) * self::TILE_W;
            $y = intdiv($i, self::ATLAS_COLS) * self::TILE_H;
            imagecopyresized(
                $atlas,
                $tile,
                $x,
                $y,
                0,
                0,
                self::TILE_W,
                self::TILE_H,
                imagesx($tile),
                imagesy($tile),
            );
            imagedestroy($tile);
        }
        return $atlas;
    }

    /**
     * Keep DeepSeek's generated portrait, but make it deliberately anonymous:
     * crop tightly into the face, collapse it to a 10x10 source and blow it back
     * up with nearest-neighbour blocks. At 320x180 it reads as "Minitel rose",
     * not as a recognisable person.
     */
    private static function zoomPixelatePortrait(\GdImage $im): void
    {
        $tiny = imagecreatetruecolor(10, 10);
        imagecopyresized($tiny, $im, 0, 0, 100, 90, 10, 10, 200, 200);
        imagecopyresized($im, $tiny, 50, 45, 0, 0, 300, 300, 10, 10);
        imagedestroy($tiny);

        $frame = imagecolorallocate($im, 255, 96, 160);
        imagerectangle($im, 48, 43, 351, 346, $frame);
    }

    private static function advertTile(int $variant): \GdImage
    {
        $im = imagecreatetruecolor(MinitelRosePoster::WIDTH, MinitelRosePoster::HEIGHT);
        imagealphablending($im, true);
        imagesavealpha($im, true);

        $ink = imagecolorallocate($im, 18, 10, 28);
        $paper = imagecolorallocate($im, 245, 214 - ($variant % 3) * 12, 70 + ($variant % 2) * 18);
        $pink = imagecolorallocate($im, 242, 52, 151);
        $cyan = imagecolorallocate($im, 55, 226, 226);
        $white = imagecolorallocate($im, 250, 245, 224);

        imagefilledrectangle($im, 0, 0, 399, 579, $paper);
        imagefilledrectangle($im, 14, 14, 385, 565, $ink);
        imagefilledrectangle($im, 26, 30, 373, 178, $pink);
        imagefilledrectangle($im, 26, 194, 373, 486, $white);
        imagefilledrectangle($im, 26, 508, 373, 536, $cyan);

        // The wall poster is viewed from several metres away in a 320x180 game.
        // Use deliberately huge bitmap typography so the gag reads immediately.
        self::drawTextScaled($im, 'VOTRE', 200, 62, $white, 5);
        self::drawTextScaled($im, 'PUB ICI', 200, 248, $ink, 5);
        self::drawTextScaled($im, 'EMPLACEMENT', 200, 382, $pink, 2);
        self::drawTextScaled($im, 'DISPONIBLE', 200, 420, $pink, 2);
        self::drawTextScaled($im, '3615 / RESERVE', 200, 520, $ink, 1);

        imagefilledrectangle($im, 38, 210, 72, 244, $cyan);
        imagefilledrectangle($im, 328, 438, 362, 472, $cyan);
        imagerectangle($im, 5, 5, 394, 574, $pink);
        return $im;
    }

    private static function drawTextScaled(\GdImage $im, string $text, int $cx, int $y, int $color, int $scale): void
    {
        $font = 5;
        $w = imagefontwidth($font) * strlen($text);
        $h = imagefontheight($font);
        $tmp = imagecreatetruecolor(max(1, $w), $h);
        $white = imagecolorallocate($tmp, 255, 255, 255);
        $black = imagecolorallocate($tmp, 0, 0, 0);
        imagefill($tmp, 0, 0, $white);
        imagestring($tmp, $font, 0, 0, $text, $black);
        $drawW = $w * $scale;
        $x0 = $cx - intdiv($drawW, 2);
        for ($py = 0; $py < $h; $py++) {
            for ($px = 0; $px < $w; $px++) {
                if ((imagecolorat($tmp, $px, $py) & 0xFF) < 128) {
                    imagefilledrectangle(
                        $im,
                        $x0 + $px * $scale,
                        $y + $py * $scale,
                        $x0 + ($px + 1) * $scale - 1,
                        $y + ($py + 1) * $scale - 1,
                        $color,
                    );
                }
            }
        }
        imagedestroy($tmp);
    }
}