#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>

#include <phosg/Filesystem.hh>
#include <phosg/Image.hh>
#include <phosg/Strings.hh>
#include <stdexcept>
#include <string>

#include "DataCodecs/Codecs.hh"
#include "ImageSaver.hh"

using namespace std;
using namespace phosg;
using namespace ResourceDASM;

ImageRGB888 render_Blev(const string& data, const ImageRGB888& tile_sheet) {
  StringReader r(data);
  string header_data = r.read(0x0E); // Format unknown
  uint16_t key = r.get_u16b();

  string decoded;
  while (!r.eof()) {
    uint8_t ch = r.get_u8();
    decoded.push_back(key ^ ch);
    key = ch;
  }

  decoded = unpack_bits(decoded);
  if (decoded.size() != 0x280) {
    throw runtime_error("incorrect decompressed level size");
  }

  ImageRGB888 ret(512, 320);
  for (size_t y = 0; y < 0x14; y++) {
    for (size_t x = 0; x < 0x20; x++) {
      // Levels are stored in column-major order, hence the weird index here
      uint8_t tile_id = decoded[x * 0x14 + y];
      // Convert non-editor tiles into annotated tiles (e.g. show boat direction
      // on water tiles)
      if (tile_id >= 0x51 && tile_id <= 0x55) { // Directional water tiles
        tile_id += 0x50;
      }
      if (tile_id == 0x30) { // Passable wall tile
        tile_id = 0xA0;
      }
      if (tile_id == 0xC5) { // Movable wall tile
        tile_id = 0xA6;
      }
      // Tiles are 16x16, and arranged in column-major order on the tilesheet
      size_t tile_sheet_x = tile_id & 0xF0;
      size_t tile_sheet_y = (tile_id << 4) & 0xF0;
      ret.copy_from(tile_sheet, x << 4, y << 4, 16, 16, tile_sheet_x, tile_sheet_y);
    }
  }

  return ret;
}

static void print_usage() {
  fwrite_fmt(stderr, "\
Usage: blobbo_render [options] <Blev-file.bin> PMP8-128.bmp [output-filename]\n\
\n\
You can get Blev files by using resource_dasm on the Blobbo game itself.\n\
To generate PMP8-128.bmp, use render_sprite to decode the PMP8 resource with ID\n\
128, which also comes from Blobbo.\n\
\n\
If no output filename is given, the output is written to <Blev-file>.<image ext>.\n\
\n" IMAGE_SAVER_HELP);
}

int main(int argc, char** argv) {
  ImageSaver image_saver;
  string input_filename;
  string tile_sheet_filename;
  string output_filename;
  for (int x = 1; x < argc; x++) {
    if (image_saver.process_cli_arg(argv[x])) {
      // Nothing
    } else if (input_filename.empty()) {
      input_filename = argv[x];
    } else if (tile_sheet_filename.empty()) {
      tile_sheet_filename = argv[x];
    } else if (output_filename.empty()) {
      output_filename = argv[x];
    } else {
      fwrite_fmt(stderr, "excess argument: {}\n", argv[x]);
      print_usage();
      return 2;
    }
  }

  if (input_filename.empty() || tile_sheet_filename.empty()) {
    fwrite_fmt(stderr, "input filename and tile sheet filename must be given\n");
    print_usage();
    return 2;
  }

  if (output_filename.empty()) {
    output_filename = input_filename;
  }

  string input_data = load_file(input_filename);

  auto tile_sheet = ImageRGB888::from_file_data(load_file(tile_sheet_filename));
  if (tile_sheet.get_width() < 16 * 16) {
    throw runtime_error("tile sheet is too narrow");
  }
  if (tile_sheet.get_height() < 16 * 16) {
    throw runtime_error("tile sheet is too short");
  }

  ImageRGB888 map = render_Blev(input_data, tile_sheet);
  output_filename = image_saver.save_image(map, output_filename);

  fwrite_fmt(stderr, "... {}\n", output_filename);
  return 0;
}