#include <stddef.h>
#include "studio/geometry.h"
#include "studio/pdf.h"
#include "studio/random.h"
#include "triangles.h"

int postcard(void * const device, const int cards)
{
    if (cards <= 0)
        return 0;
    const vector pagesize = landscape(a6);
    const vector margin = scalar(7.5 mm);
    const vector grid = {.x = 13.0, .y = 9.0};
    const vector tile = divide(subtract(multiply(margin, scalar(2.0)), pagesize), grid);
    const vector squares = scalar(min(tile.x, tile.y));
    const matrix layout = scale(squares, translate(divide(subtract(multiply(grid, squares), pagesize), scalar(2.0)), identity()));
    uint32_t triangles[(90 * 90) - 1] = {0};
    static_assert(count(triangles) <= UINT32_MAX, "");
    for (uint32_t number = 0; number < count(triangles); ++number)
        triangles[number] = number;
    assert(grid.x <= count(triangles) / grid.y);
    struct pdf pdf = startpdf(
        (struct pdf){.write = output, .device = device, .title = "triangles", .author = "David W. Speck"}
    );
    const size_t resources = (pdf = dictionary(pdf, "/ProcSet [/PDF]")).object.number;
    for (unsigned card = 0; card < (unsigned)cards; ++card) {
        const struct pdf stream = (pdf = startpage(pdf, pagesize, resources));
        for (unsigned column = 0; column <= grid.x; ++column) {
            pdf = generate(point(generate(point(pdf,
                transform((vector){.x = column, .y = 0}, layout)), "m "),
                transform((vector){.x = column, .y = grid.y}, layout)), "l\n"
            );
        }
        for (unsigned row = 0; row <= grid.y; ++row) {
            pdf = generate(point(generate(point(pdf,
                transform((vector){.x = 0, .y = row}, layout)), "m "),
                transform((vector){.x = grid.x, .y = row}, layout)), "l\n"
            );
        }
        pdf = generate(pdf, "0 w S\n");
        for (unsigned column = 0; column < grid.x; ++column) {
            for (unsigned row = 0; row < grid.y; ++row) {
                const size_t cell = (column * grid.y) + row;
                const size_t pick = cell + any((count(triangles) - 1) - cell);
                const uint32_t picked = triangles[pick];
                triangles[pick] = triangles[cell];
                triangles[cell] = picked;
                const struct vertices object = triangle(shape(picked));
                const matrix position = translate((vector){.x = column, .y = row}, layout);
                pdf = generate(generate(point(generate(point(generate(point(pdf,
                    transform(object.A, position)), "m "),
                    transform(object.B, position)), "l "),
                    transform(object.C, position)), "l "),
                    "h\n"
                );
            }
        }
        pdf = endpage(generate(pdf, "1 j 1 M %0.2f w S\n", 0.4 mm), stream);
    }
    const size_t textresources = (pdf = dictionary(pdf,
        "/ProcSet [/PDF /text] /Font <<\n"
        "  /Courier-Bold <<\n" 
        "    /Type /Font /Subtype /Type1 /Name /Courier-Bold /BaseFont /Courier-Bold /Encoding /MacRomanEncoding\n"
        "  >> /Courier-BoldOblique <<\n"
        "    /Type /Font /Subtype /Type1 /Name /Courier-BoldOblique /BaseFont /Courier-BoldOblique /Encoding /MacRomanEncoding\n"
        "  >>\n"
        ">> "
    )).object.number;
    const struct pdf stream = (pdf = startpage(pdf, pagesize, textresources));
    const double fontsize = 10;
    const double leading = fontsize * 1.2;
    pdf = generate(point(generate(pdf,
        "BT %0.2f TL ", leading), add((vector){.y = 5 * leading}, margin)), "Td\n"
        "/Courier-Bold %0.2f Tf (triangles) '\n"
        "/Courier-BoldOblique %0.2f Tf (dreiecke) '\n"
        "/Courier-Bold %0.2f Tf () '\n"
        "(David W. Speck, 2025) '\n"
        "(rndmao.org/dws) '\n"
        "ET\n", fontsize, fontsize, fontsize
    );
    pdf = endpdf(endpage(pdf, stream));
    return 1;
}