/*
  StarForth — Steady-State Virtual Machine Runtime

  Copyright (c) 2023–2025 Robert A. James
  All rights reserved.

  Licensed under the StarForth License, Version 1.0.
*/

/**
 * ttftest.c — Host-side unit test for src/starkernel/hal/ttf.c (FABRIC.md
 * item 4.3.7). No QEMU needed, same pattern as tools/README.md's fbtest.c
 * entry (that file is itself missing from tools/ — stale doc, reported
 * separately, not fixed here).
 *
 * Expected values below were independently computed by a from-scratch
 * Python/struct reference reader (not this codebase's parser), against
 * JetBrainsMono-Regular.ttf.
 *
 * Usage: ./ttftest <path-to-ttf>
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "../include/starkernel/ttf.h"

typedef struct {
    uint32_t codepoint;
    uint32_t expect_glyph;
    int16_t expect_contours;
    int16_t expect_xmin, expect_ymin, expect_xmax, expect_ymax;
    uint32_t expect_glyf_offset;
    uint32_t expect_glyf_length;
} expect_t;

static const expect_t EXPECTED[] = {
    /*   cp     glyph   nc  xmin ymin xmax ymax    off      len */
    {0x0041, 1, 2, 50, 0, 550, 730, 35536, 112},   /* 'A' */
    {0x0061, 198, 2, 67, -10, 508, 560, 46968, 244}, /* 'a' */
    {0x0030, 737, 3, 80, -10, 520, 740, 92152, 184}, /* '0' */
    {0x002E, 908, 1, 218, -10, 382, 152, 110044, 72}, /* '.' */
    {0x0021, 913, 2, 225, -5, 375, 730, 110632, 108}, /* '!' */
    {0x0040, 1151, 2, 45, -180, 560, 740, 144400, 224}, /* '@' */
    {0x0020, 821, 0, 0, 0, 0, 0, 99448, 0},         /* space, empty glyph */
};

static int failures = 0;

static void check_eq_i(const char *what, uint32_t cp, long got, long want) {
    if (got != want) {
        printf("  FAIL U+%04X %s: got %ld want %ld\n", cp, what, got, want);
        failures++;
    }
}

int main(int argc, char **argv) {
    FILE *fp;
    long size;
    uint8_t *buf;
    ttf_font_t font;
    int rc;
    size_t i;

    if (argc < 2) {
        fprintf(stderr, "usage: %s <path-to-ttf>\n", argv[0]);
        return 2;
    }

    fp = fopen(argv[1], "rb");
    if (!fp) {
        perror("fopen");
        return 2;
    }
    fseek(fp, 0, SEEK_END);
    size = ftell(fp);
    fseek(fp, 0, SEEK_SET);
    buf = malloc((size_t) size);
    if (!buf || fread(buf, 1, (size_t) size, fp) != (size_t) size) {
        fprintf(stderr, "read failed\n");
        return 2;
    }
    fclose(fp);

    rc = ttf_parse(buf, (uint32_t) size, &font);
    if (rc != TTF_OK) {
        printf("ttf_parse failed: rc=%d\n", rc);
        return 1;
    }
    printf("parsed: unitsPerEm=%u numGlyphs=%u indexToLocFormat=%d has_cmap=%d\n",
           font.units_per_em, font.num_glyphs, font.index_to_loc_format, font.has_cmap);

    for (i = 0; i < sizeof(EXPECTED) / sizeof(EXPECTED[0]); i++) {
        const expect_t *e = &EXPECTED[i];
        uint32_t gid = ttf_codepoint_to_glyph(&font, e->codepoint);
        ttf_glyph_header_t hdr;
        int hrc;

        printf("U+%04X -> glyph %u (want %u)\n", e->codepoint, gid, e->expect_glyph);
        check_eq_i("glyph", e->codepoint, gid, e->expect_glyph);

        hrc = ttf_glyph_header(&font, gid, &hdr);
        if (hrc != TTF_OK) {
            printf("  FAIL U+%04X ttf_glyph_header rc=%d\n", e->codepoint, hrc);
            failures++;
            continue;
        }
        check_eq_i("num_contours", e->codepoint, hdr.num_contours, e->expect_contours);
        check_eq_i("x_min", e->codepoint, hdr.x_min, e->expect_xmin);
        check_eq_i("y_min", e->codepoint, hdr.y_min, e->expect_ymin);
        check_eq_i("x_max", e->codepoint, hdr.x_max, e->expect_xmax);
        check_eq_i("y_max", e->codepoint, hdr.y_max, e->expect_ymax);
        check_eq_i("glyf_offset", e->codepoint, hdr.glyf_offset, e->expect_glyf_offset);
        check_eq_i("glyf_length", e->codepoint, hdr.glyf_length, e->expect_glyf_length);
    }

    free(buf);

    if (failures) {
        printf("%d check(s) FAILED\n", failures);
        return 1;
    }
    printf("all checks passed\n");
    return 0;
}