/**
 * Copyright (c) 2026 Dominic Masters
 *
 * This software is released under the MIT License.
 * https://opensource.org/licenses/MIT
 */

#include "dusktest.h"
#include "asset/asset.h"
#include "asset/assetfile.h"
#include "util/memory.h"
#include <zip.h>

// ============================================================
// Fixtures
// ============================================================

static const char_t *TXT_HELLO = "Hello, World!";
static const char_t *TXT_LINES = "line one\nline two\r\nline three";
static const char_t *TXT_LONGLINE = "abcdefghijklmnopqrstuvwxyz\n";

// ============================================================
// In-memory ZIP
// ============================================================

static zip_t *g_zip = NULL;

static int file_zip_add(
  zip_t *za, const char_t *name, const void *data, size_t len
) {
  zip_source_t *s = zip_source_buffer(za, data, len, 0);
  return (int)zip_file_add(za, name, s, ZIP_FL_OVERWRITE);
}

static int zip_setup(void **state) {
  zip_error_t err;
  zip_error_init(&err);

  zip_source_t *write_src = zip_source_buffer_create(NULL, 0, 1, &err);
  if(!write_src) return -1;

  zip_t *za = zip_open_from_source(write_src, ZIP_TRUNCATE, &err);
  if(!za) { zip_source_free(write_src); return -1; }

  if(
    file_zip_add(za, "hello.txt", TXT_HELLO, strlen(TXT_HELLO)) < 0 ||
    file_zip_add(za, "empty.txt", "", 0) < 0 ||
    file_zip_add(za, "lines.txt", TXT_LINES, strlen(TXT_LINES)) < 0 ||
    file_zip_add(za, "longline.txt", TXT_LONGLINE, strlen(TXT_LONGLINE)) < 0
  ) {
    zip_close(za); return -1;
  }

  zip_source_keep(write_src);
  if(zip_close(za) != 0) { zip_source_free(write_src); return -1; }

  zip_stat_t zs;
  memset(&zs, 0, sizeof(zs));
  if(zip_source_stat(write_src, &zs) != 0 || !(zs.valid & ZIP_STAT_SIZE)) {
    zip_source_free(write_src); return -1;
  }

  void *zipbuf = malloc((size_t)zs.size);
  if(!zipbuf) { zip_source_free(write_src); return -1; }

  if(zip_source_open(write_src) != 0) {
    free(zipbuf); zip_source_free(write_src); return -1;
  }
  zip_source_read(write_src, zipbuf, (zip_uint64_t)zs.size);
  zip_source_close(write_src);
  zip_source_free(write_src);

  zip_error_init(&err);
  zip_source_t *read_src = zip_source_buffer_create(
    zipbuf, (zip_uint64_t)zs.size, 1, &err
  );
  if(!read_src) { free(zipbuf); return -1; }

  g_zip = zip_open_from_source(read_src, 0, &err);
  if(!g_zip) { zip_source_free(read_src); return -1; }

  ASSET.zip = g_zip;
  return 0;
}

static int zip_teardown(void **state) {
  if(g_zip) { zip_close(g_zip); g_zip = NULL; }
  ASSET.zip = NULL;
  return 0;
}

// ============================================================
// assetFileInit tests
// ============================================================

static void test_assetFileInit_valid(void **state) {
  assetfile_t file;
  errorret_t ret = assetFileInit(&file, "hello.txt", NULL, NULL);
  assert_true(errorIsOk(ret));
  assert_int_equal((int)file.size, (int)strlen(TXT_HELLO));

  errorret_t disposeRet = assetFileDispose(&file);
  assert_true(errorIsOk(disposeRet));
  assert_int_equal(memoryGetAllocatedCount(), 0);
}

static void test_assetFileInit_missing_file(void **state) {
  assetfile_t file;
  errorret_t ret = assetFileInit(&file, "nonexistent.txt", NULL, NULL);
  assert_true(errorIsNotOk(ret));
  errorCatch(ret);
  assert_int_equal(memoryGetAllocatedCount(), 0);
}

static void test_assetFileInit_zero_size_errors(void **state) {
  assetfile_t file;
  errorret_t ret = assetFileInit(&file, "empty.txt", NULL, NULL);
  assert_true(errorIsNotOk(ret));
  errorCatch(ret);
  assert_int_equal(memoryGetAllocatedCount(), 0);
}

// ============================================================
// Open / read / close tests
// ============================================================

static void test_assetFile_open_read_close(void **state) {
  assetfile_t file;
  assetFileInit(&file, "hello.txt", NULL, NULL);

  errorret_t ret = assetFileOpen(&file);
  assert_true(errorIsOk(ret));

  char_t buf[32];
  ret = assetFileRead(&file, buf, strlen(TXT_HELLO));
  assert_true(errorIsOk(ret));
  buf[strlen(TXT_HELLO)] = '\0';
  assert_string_equal(buf, TXT_HELLO);
  assert_int_equal((int)file.position, (int)strlen(TXT_HELLO));
  assert_int_equal((int)file.lastRead, (int)strlen(TXT_HELLO));

  ret = assetFileClose(&file);
  assert_true(errorIsOk(ret));
  assert_null(file.zipFile);

  errorret_t disposeRet = assetFileDispose(&file);
  assert_true(errorIsOk(disposeRet));
  assert_int_equal(memoryGetAllocatedCount(), 0);
}

static void test_assetFile_read_skip_advances_position_by_exactly_n(
  void **state
) {
  // Regression test: assetFileRead's NULL-buffer skip path used to advance
  // file->position by 2x the skipped amount (the recursive real-read call
  // already advances it once, and the skip loop wrongly advanced it again).
  assetfile_t file;
  assetFileInit(&file, "hello.txt", NULL, NULL);
  assetFileOpen(&file);

  errorret_t ret = assetFileRead(&file, NULL, 7);  // skip "Hello, "
  assert_true(errorIsOk(ret));
  assert_int_equal((int)file.position, 7);
  assert_int_equal((int)file.lastRead, 7);

  char_t buf[16];
  ret = assetFileRead(&file, buf, 6);  // "World!"
  assert_true(errorIsOk(ret));
  buf[6] = '\0';
  assert_string_equal(buf, "World!");
  assert_int_equal((int)file.position, 13);

  assetFileClose(&file);
  errorret_t disposeRet = assetFileDispose(&file);
  assert_true(errorIsOk(disposeRet));
  assert_int_equal(memoryGetAllocatedCount(), 0);
}

static void test_assetFile_skip_spanning_multiple_chunks(void **state) {
  // The skip loop reads through a 256-byte scratch buffer per chunk; verify
  // a skip larger than that scratch buffer still lands on the right byte.
  assetfile_t file;
  assetFileInit(&file, "longline.txt", NULL, NULL);
  assetFileOpen(&file);

  // longline.txt is the 26-letter alphabet + '\n' = 27 bytes; skip the
  // first 25 letters (a..y), leaving "z\n".
  errorret_t ret = assetFileRead(&file, NULL, 25);
  assert_true(errorIsOk(ret));
  assert_int_equal((int)file.position, 25);

  char_t buf[4];
  ret = assetFileRead(&file, buf, 2);
  assert_true(errorIsOk(ret));
  buf[2] = '\0';
  assert_string_equal(buf, "z\n");

  assetFileClose(&file);
  errorret_t disposeRet = assetFileDispose(&file);
  assert_true(errorIsOk(disposeRet));
  assert_int_equal(memoryGetAllocatedCount(), 0);
}

static void test_assetFile_rewind_reads_from_start_again(void **state) {
  assetfile_t file;
  assetFileInit(&file, "hello.txt", NULL, NULL);
  assetFileOpen(&file);

  char_t buf[16];
  assetFileRead(&file, buf, 5);
  buf[5] = '\0';
  assert_string_equal(buf, "Hello");

  errorret_t ret = assetFileRewind(&file);
  assert_true(errorIsOk(ret));
  assert_int_equal((int)file.position, 0);

  assetFileRead(&file, buf, 5);
  buf[5] = '\0';
  assert_string_equal(buf, "Hello");

  assetFileClose(&file);
  errorret_t disposeRet = assetFileDispose(&file);
  assert_true(errorIsOk(disposeRet));
  assert_int_equal(memoryGetAllocatedCount(), 0);
}

static void test_assetFile_rewind_noop_at_start(void **state) {
  assetfile_t file;
  assetFileInit(&file, "hello.txt", NULL, NULL);
  assetFileOpen(&file);

  // Never having read anything, position is already 0 -- rewind must be a
  // cheap no-op rather than closing/reopening the handle.
  errorret_t ret = assetFileRewind(&file);
  assert_true(errorIsOk(ret));
  assert_non_null(file.zipFile);

  assetFileClose(&file);
  errorret_t disposeRet = assetFileDispose(&file);
  assert_true(errorIsOk(disposeRet));
  assert_int_equal(memoryGetAllocatedCount(), 0);
}

static void test_assetFile_dispose_closes_open_handle(void **state) {
  assetfile_t file;
  assetFileInit(&file, "hello.txt", NULL, NULL);
  assetFileOpen(&file);

  errorret_t ret = assetFileDispose(&file);
  assert_true(errorIsOk(ret));
  assert_null(file.zipFile);
  assert_int_equal((int)file.size, 0);

  assert_int_equal(memoryGetAllocatedCount(), 0);
}

// ============================================================
// assetFileReadEntire tests
// ============================================================

static void test_assetFileReadEntire_reads_full_contents(void **state) {
  assetfile_t file;
  assetFileInit(&file, "hello.txt", NULL, NULL);

  uint8_t *buffer = NULL;
  size_t size = 0;
  errorret_t ret = assetFileReadEntire(&file, &buffer, &size);
  assert_true(errorIsOk(ret));
  assert_non_null(buffer);
  assert_int_equal((int)size, (int)strlen(TXT_HELLO));
  assert_memory_equal(buffer, TXT_HELLO, size);

  // The file handle is closed again by the time this returns.
  assert_null(file.zipFile);

  memoryFree(buffer);
  errorret_t disposeRet = assetFileDispose(&file);
  assert_true(errorIsOk(disposeRet));
  assert_int_equal(memoryGetAllocatedCount(), 0);
}

// ============================================================
// Line reader tests
// ============================================================

static void test_lineReader_reads_lines_stripping_crlf(void **state) {
  assetfile_t file;
  assetFileInit(&file, "lines.txt", NULL, NULL);
  assetFileOpen(&file);

  uint8_t readBuf[64];
  uint8_t outBuf[64];
  assetfilelinereader_t reader;
  assetFileLineReaderInit(
    &reader, &file, readBuf, sizeof(readBuf), outBuf, sizeof(outBuf)
  );

  errorret_t ret = assetFileLineReaderNext(&reader);
  assert_true(errorIsOk(ret));
  assert_string_equal((char_t *)outBuf, "line one");

  ret = assetFileLineReaderNext(&reader);
  assert_true(errorIsOk(ret));
  assert_string_equal((char_t *)outBuf, "line two");  // \r stripped

  ret = assetFileLineReaderNext(&reader);
  assert_true(errorIsOk(ret));
  assert_string_equal((char_t *)outBuf, "line three");  // no trailing \n

  assetFileClose(&file);
  errorret_t disposeRet = assetFileDispose(&file);
  assert_true(errorIsOk(disposeRet));
  assert_int_equal(memoryGetAllocatedCount(), 0);
}

static void test_lineReader_next_past_eof_throws(void **state) {
  assetfile_t file;
  assetFileInit(&file, "lines.txt", NULL, NULL);
  assetFileOpen(&file);

  uint8_t readBuf[64];
  uint8_t outBuf[64];
  assetfilelinereader_t reader;
  assetFileLineReaderInit(
    &reader, &file, readBuf, sizeof(readBuf), outBuf, sizeof(outBuf)
  );

  assetFileLineReaderNext(&reader);
  assetFileLineReaderNext(&reader);
  assetFileLineReaderNext(&reader);  // consumes "line three", the last line

  errorret_t ret = assetFileLineReaderNext(&reader);
  assert_true(errorIsNotOk(ret));
  errorCatch(ret);

  assetFileClose(&file);
  errorret_t disposeRet = assetFileDispose(&file);
  assert_true(errorIsOk(disposeRet));
  assert_int_equal(memoryGetAllocatedCount(), 0);
}

static void test_lineReader_small_read_buffer_spans_multiple_fills(
  void **state
) {
  // readBuffer is far smaller than the line, forcing assetFileLineReaderFill
  // to be called repeatedly (and to slide unread bytes down) before the
  // newline is finally seen.
  assetfile_t file;
  assetFileInit(&file, "longline.txt", NULL, NULL);
  assetFileOpen(&file);

  uint8_t readBuf[4];
  uint8_t outBuf[64];
  assetfilelinereader_t reader;
  assetFileLineReaderInit(
    &reader, &file, readBuf, sizeof(readBuf), outBuf, sizeof(outBuf)
  );

  errorret_t ret = assetFileLineReaderNext(&reader);
  assert_true(errorIsOk(ret));
  assert_string_equal((char_t *)outBuf, "abcdefghijklmnopqrstuvwxyz");

  assetFileClose(&file);
  errorret_t disposeRet = assetFileDispose(&file);
  assert_true(errorIsOk(disposeRet));
  assert_int_equal(memoryGetAllocatedCount(), 0);
}

// ============================================================
// main
// ============================================================

int main(void) {
  assertInit();
  const struct CMUnitTest tests[] = {
    cmocka_unit_test_setup_teardown(test_assetFileInit_valid, zip_setup, zip_teardown),
    cmocka_unit_test_setup_teardown(test_assetFileInit_missing_file, zip_setup, zip_teardown),
    cmocka_unit_test_setup_teardown(test_assetFileInit_zero_size_errors, zip_setup, zip_teardown),

    cmocka_unit_test_setup_teardown(test_assetFile_open_read_close, zip_setup, zip_teardown),
    cmocka_unit_test_setup_teardown(test_assetFile_read_skip_advances_position_by_exactly_n, zip_setup, zip_teardown),
    cmocka_unit_test_setup_teardown(test_assetFile_skip_spanning_multiple_chunks, zip_setup, zip_teardown),
    cmocka_unit_test_setup_teardown(test_assetFile_rewind_reads_from_start_again, zip_setup, zip_teardown),
    cmocka_unit_test_setup_teardown(test_assetFile_rewind_noop_at_start, zip_setup, zip_teardown),
    cmocka_unit_test_setup_teardown(test_assetFile_dispose_closes_open_handle, zip_setup, zip_teardown),

    cmocka_unit_test_setup_teardown(test_assetFileReadEntire_reads_full_contents, zip_setup, zip_teardown),

    cmocka_unit_test_setup_teardown(test_lineReader_reads_lines_stripping_crlf, zip_setup, zip_teardown),
    cmocka_unit_test_setup_teardown(test_lineReader_next_past_eof_throws, zip_setup, zip_teardown),
    cmocka_unit_test_setup_teardown(test_lineReader_small_read_buffer_spans_multiple_fills, zip_setup, zip_teardown),
  };
  return cmocka_run_group_tests(tests, NULL, NULL);
}