/**
 * Copyright (c) 2025 Dominic Masters
 * 
 * This software is released under the MIT License.
 * https://opensource.org/licenses/MIT
 */

#include "asset.h"
#include "util/memory.h"
#include "console/console.h"
#include "util/string.h"
#include "assert/assert.h"

#define ASSET_ASSET_FILE "dusk.dsk"

asset_t ASSET;

errorret_t assetInit(void) {
  memoryZero(&ASSET, sizeof(asset_t));

  // Open zip file
  char_t searchPath[FILENAME_MAX];
  consolevar_t *var = consoleVarGet("sys_path");
  const char_t *sysPath = var ? var->value : ".";
  for(int32_t i = 0; i < ASSET_SEARCH_PATHS_COUNT; i++) {
    sprintf(
      searchPath,
      ASSET_SEARCH_PATHS[i],
      sysPath,
      ASSET_ASSET_FILE
    );

    // Try open
    ASSET.zip = zip_open(searchPath, ZIP_RDONLY, NULL);
    if(ASSET.zip == NULL) continue;
    consolePrint("Opened asset file: %s", searchPath);
    break;
  }
  
  // Did we open the asset?
  if(ASSET.zip == NULL) errorThrow("Failed to open asset file.");

  errorOk();
}

void assetLoad(
  const char_t *filename,
  void (*callback)(void* data),
  void *data
) {
  assertNotNull(filename, "Filename cannot be NULL.");
  assertTrue(strlen(filename) < ASSET_FILENAME_MAX, "Filename too long.");
  assertTrue(strlen(filename) > 0, "Filename cannot be empty.");

  assertTrue(
    ASSET.state != ASSET_STATE_LOADING,
    "Asset system is already loading an asset."
  );

  // Determine the asset map type we are expecting based on the extension.
  const assetmap_t *expected = &ASSET_MAP[0];
  do {
    if(stringEndsWith(filename, expected->extension)) break;
    expected++;
  } while(expected->extension);
  assertNotNull(expected->extension, "Unknown asset type.");
  
  // Pass off to the thread to begin loading.
  ASSET.callback = callback;
  ASSET.callbackData = data;
  ASSET.errorState = ERROR_STATE_INIT;
  ASSET.state = ASSET_STATE_LOADING;
  stringCopy(ASSET.filename, filename, ASSET_FILENAME_MAX);
  memoryZero(&ASSET.data, sizeof(ASSET.data));

  // For the sake of testing I'm going to do blocking load, fun stuff.
  zip_file_t *file = zip_fopen(ASSET.zip, filename, 0);
  if(file == NULL) {
    ASSET.state = ASSET_STATE_ERROR;
    ASSET.error = errorCreate(
      &ASSET.errorState,
      "Failed to open asset: %s",
      filename
    );
    if(ASSET.callback) ASSET.callback(ASSET.callbackData);
    return;
  }

  printf("Loading asset: %s\n", filename);

  // Determine length of the file (uncompressed)
  struct zip_stat st;
  if(zip_stat(ASSET.zip, filename, 0, &st) != 0) {
    zip_fclose(file);
    ASSET.state = ASSET_STATE_ERROR;
    ASSET.error = errorCreate(
      &ASSET.errorState,
      "Failed to stat asset: %s",
      filename
    );
    if(ASSET.callback) ASSET.callback(ASSET.callbackData);
    return;
  }

  if(st.size > sizeof(ASSET.data.palette)) {
    zip_fclose(file);
    ASSET.state = ASSET_STATE_ERROR;
    ASSET.error = errorCreate(
      &ASSET.errorState,
      "Asset size mismatch: %s (got %d, expected %d)",
      filename,
      (int)st.size,
      (int)sizeof(ASSET.data.palette)
    );
    if(ASSET.callback) ASSET.callback(ASSET.callbackData);
    return;
  }

  // Read entire file into the asset data.
  zip_fread(file, &ASSET.data, st.size); 
  zip_fclose(file);
  ASSET.state = ASSET_STATE_LOADED;

  if(memoryCompare(
    ASSET.data.header, expected->header, ASSET_HEADER_LENGTH
  ) != 0) {
    ASSET.state = ASSET_STATE_ERROR;
    ASSET.error = errorCreate(
      &ASSET.errorState,
      "Asset header mismatch: %s (got %c%c%c, expected %c%c%c)",
      filename,
      ASSET.data.header[0],
      ASSET.data.header[1],
      ASSET.data.header[2],
      expected->header[0],
      expected->header[1],
      expected->header[2]
    );
    if(ASSET.callback) ASSET.callback(ASSET.callbackData);
    return;
  }

  // Parse the asset.
  assertNotNull(expected->parser, "Asset parser cannot be NULL.");
  expected->parser();

  printf("Loaded asset: %s\n", filename);
  if(ASSET.callback) ASSET.callback(ASSET.callbackData);
}

void assetDispose(void) {
  if(ASSET.zip != NULL) {
    zip_close(ASSET.zip);
    ASSET.zip = NULL;
  }
}