// Part of JoeyLib, Copyright (c) 2026 Scott Duensing, under the MIT License.
// See LICENSE.md for license information.
// SPDX-License-Identifier: MIT
//
// keysCells.c - read which of KEYS's named-key cells are lit off a
// screenshot.
//
//     keysCells PNG [--at X,Y] [--scale S]
//
// KEYS (examples/keys) draws a cell for each named key, lit (color 2,
// green) while jlKeyDown says it is down and dark gray (color 1)
// otherwise. This reads the cells of its fourth row that a port gives a
// second physical key for -- Return, Ctrl, Alt, Up, Down, Left, and Right
// -- at the middle of each, and prints one digit a cell, in that order: 1
// lit, 0 not, ? neither color.
//
// --at: where the stage's top left is in the screenshot (default 0,0).
// --scale: screen pixels a stage pixel (default 1). A point off the
// screenshot is fatal (exit 1); a bad command line exits 2.

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

#include "gateArg.h"
#include "gateImage.h"
#include "toolFile.h"

#define TOOL_NAME    "keysCells"
// examples/keys: CELL_W x CELL_H cells GAP apart from (MARGIN_X,
// MARGIN_Y), the named keys in row 4 at these columns.
#define CELL_W       28
#define CELL_H       26
#define GAP          4
#define MARGIN_X     2
#define MARGIN_Y     2
#define ROW          4
#define COLUMN_COUNT 7u
// KEYS's colors 1 and 2, and how near a pixel must be: a 15- or 16-bit
// screen is off by at most 8 a gun.
#define UNLIT_INDEX  1u
#define LIT_INDEX    2u
#define MAX_DIST     (3u * 9u * 9u)


// Return, Ctrl, Alt, Up, Down, Left, Right.
static const long kColumns[COLUMN_COUNT] = { 2, 3, 4, 5, 6, 7, 8 };

static const char *const kUsage[] = {
    "keysCells - read which of KEYS's named-key cells are lit off a screenshot.",
    "",
    "KEYS (examples/keys) draws a cell for each named key, lit (color 2, green)",
    "while jlKeyDown says it is down and dark gray (color 1) otherwise. This",
    "reads the cells of its fourth row that a port gives a second physical key",
    "for -- Return, Ctrl, Alt, Up, Down, Left, and Right -- at the middle of",
    "each, and prints one digit a cell, in that order: 1 lit, 0 not, ? neither",
    "color.",
    "",
    "    keysCells PNG [--at X,Y] [--scale S]",
    "",
    "--at: where the stage's top left is in the screenshot (default 0,0).",
    "--scale: screen pixels a stage pixel (default 1)."
};


int main(int argc, char **argv) {
    GateImageT     img;
    const char    *png;
    const uint8_t *pixel;
    uint16_t       words[GATE_KEYS_COLORS];
    uint8_t        lit[GATE_RGB_BYTES];
    uint8_t        unlit[GATE_RGB_BYTES];
    char           digits[COLUMN_COUNT + 1u];
    long           atX;
    long           atY;
    long           scale;
    long           x;
    long           y;
    uint32_t       i;
    int            arg;

    toolFileName(TOOL_NAME);
    png   = NULL;
    atX   = 0;
    atY   = 0;
    scale = 1;
    for (arg = 1; arg < argc; arg++) {
        if (strcmp(argv[arg], "--at") == 0 && arg + 1 < argc) {
            gateArgPair("at", argv[++arg], ',', &atX, &atY);
        } else if (strcmp(argv[arg], "--scale") == 0 && arg + 1 < argc) {
            scale = gateArgLong("scale", argv[++arg]);
            if (scale < 1) {
                gateArgBad("scale", argv[arg]);
            }
        } else if (argv[arg][0] == '-' || png != NULL) {
            return gateUsage(kUsage, GATE_COUNT_OF(kUsage));
        } else {
            png = argv[arg];
        }
    }
    if (png == NULL) {
        return gateUsage(kUsage, GATE_COUNT_OF(kUsage));
    }
    gateImageLoad(png, &img);
    gateKeysPalette(words);
    gateRgb12(words[LIT_INDEX], lit);
    gateRgb12(words[UNLIT_INDEX], unlit);
    // Each cell's middle, on the screenshot.
    y = atY + (MARGIN_Y + ROW * (CELL_H + GAP) + CELL_H / 2) * scale;
    for (i = 0; i < COLUMN_COUNT; i++) {
        x = atX + (MARGIN_X + kColumns[i] * (CELL_W + GAP) + CELL_W / 2) * scale;
        if (!gateImageHas(&img, x, y)) {
            toolFail("cell %u's middle, %ld,%ld, is off the %ux%u screenshot", (unsigned)i, x, y, (unsigned)img.width, (unsigned)img.height);
        }
        pixel = gateImagePixel(&img, (uint32_t)x, (uint32_t)y);
        if (gateDistance(pixel, lit) <= MAX_DIST) {
            digits[i] = '1';
        } else if (gateDistance(pixel, unlit) <= MAX_DIST) {
            digits[i] = '0';
        } else {
            digits[i] = '?';
        }
    }
    digits[COLUMN_COUNT] = '\0';
    printf("%s\n", digits);
    gateImageFree(&img);
    return 0;
}