// staxibake -- generate the Space Taxi cel bank (.spr) for offline
// sprite pre-compilation. Runs on the host: it links the game's shared
// cel table (stCels.c) and the C64 sprite bitmaps (stC64Data.c) and
// writes the cross-platform JSP1 sprite bank in kStCels order. The
// per-target spritebake then compiles it to a .spc the game loads at
// boot with jlSpriteBankLoadPrecompiled, so no cel is JIT-compiled on
// the 65816 (which costs ~0.4 s each).
//
// Usage: staxibake OUTPUT.spr

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

#include "stCels.h"
#include "stC64Data.h"

// JSP1 header (mirrors tools/spritebake + jlSpriteBankLoad): magic,
// target byte (0 = cross-platform chunky), has-palette, w/h tiles,
// cell count LE16, then a 32-byte palette block, all in 44 bytes.
#define SPR_HEADER_BYTES   44u
#define SPR_OFF_TARGET      4u
#define SPR_OFF_HAS_PAL     5u
#define SPR_OFF_WIDTH       6u
#define SPR_OFF_HEIGHT      7u
#define SPR_OFF_CELLS       8u


int main(int argc, char **argv) {
    uint8_t  header[SPR_HEADER_BYTES];
    FILE    *out;
    uint16_t i;

    if (argc < 2) {
        fprintf(stderr, "usage: staxibake OUTPUT.spr\n");
        return 2;
    }
    out = fopen(argv[1], "wb");
    if (out == NULL) {
        fprintf(stderr, "staxibake: cannot write %s\n", argv[1]);
        return 1;
    }
    memset(header, 0, sizeof(header));
    memcpy(header, "JSP1", 4);
    header[SPR_OFF_TARGET]  = 0u;                       // cross-platform chunky
    header[SPR_OFF_HAS_PAL] = 0u;                       // the game owns its palette
    header[SPR_OFF_WIDTH]   = (uint8_t)ST_CEL_TILES;
    header[SPR_OFF_HEIGHT]  = (uint8_t)ST_CEL_TILES;
    header[SPR_OFF_CELLS]   = (uint8_t)(kStCelCount & 0xFFu);
    header[SPR_OFF_CELLS + 1u] = (uint8_t)(kStCelCount >> 8);
    if (fwrite(header, 1, SPR_HEADER_BYTES, out) != SPR_HEADER_BYTES) {
        fprintf(stderr, "staxibake: header write failed\n");
        fclose(out);
        return 1;
    }
    for (i = 0u; i < kStCelCount; i++) {
        uint8_t        blob[ST_CEL_BYTES];
        const uint8_t *bm = stC64SpriteBitmap((uint8_t)(kStCels[i].ptr - ST_SPRITE_PTR_FIRST));

        stCelBlob(bm, kStCels[i].multi, kStCels[i].color, kStCels[i].mc0, kStCels[i].mc1, blob);
        if (fwrite(blob, 1, ST_CEL_BYTES, out) != ST_CEL_BYTES) {
            fprintf(stderr, "staxibake: cel %u write failed\n", (unsigned)i);
            fclose(out);
            return 1;
        }
    }
    fclose(out);
    fprintf(stderr, "staxibake: wrote %u cels (%ux%u tiles) -> %s\n", (unsigned)kStCelCount, (unsigned)ST_CEL_TILES, (unsigned)ST_CEL_TILES, argv[1]);
    return 0;
}