/**
 * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 * SPDX-License-Identifier: Apache-2.0.
 */

#include "logging_test_utilities.h"

#include <aws/common/log_writer.h>

#include <aws/common/file.h>
#include <aws/common/string.h>
#include <aws/testing/aws_test_harness.h>

#include <errno.h>
#include <stdio.h>

#ifndef _WIN32
#    include <sys/file.h>
#endif /* _WIN32 */

#define TEST_WRITER_MAX_BUFFER_SIZE 4096

int do_default_log_writer_test(
    struct aws_log_writer *writer,
    const char *test_file_name,
    const char *expected_file_content,
    const struct aws_string *output,
    FILE *close_fp) {

    int result = writer->vtable->write(writer, output);

    aws_log_writer_clean_up(writer);

    /*
     * When we redirect stdout/stderr to a file, we need to close the file manually since the writer implementations do
     * not do so.
     */
    if (close_fp != NULL) {
        fclose(close_fp);
    }

    char buffer[TEST_WRITER_MAX_BUFFER_SIZE];
    FILE *file = aws_fopen(test_file_name, "r");
    int open_error = errno;
    size_t bytes_read = 0;

    if (file != NULL) {
        bytes_read = fread(buffer, 1, TEST_WRITER_MAX_BUFFER_SIZE - 1, file);
        fclose(file);
    }
    remove(test_file_name);

    /*
     * Check that the write call was successful
     */
    ASSERT_TRUE(result == AWS_OP_SUCCESS, "Writing operation failed");

    /*
     * Check the file was read successfully
     */
    ASSERT_TRUE(
        file != NULL, "Unable to open output file \"%s\" to verify contents. Error: %d", test_file_name, open_error);
    ASSERT_TRUE(bytes_read >= 0, "Failed to read test output file \"%s\"", test_file_name);

    /*
     * add end of string marker
     */
    buffer[bytes_read] = 0;

    /*
     * Check file contents
     */
    ASSERT_TRUE(
        strcmp(buffer, expected_file_content) == 0,
        "Expected log file to contain:\n\n%s\n\nbut instead it contained:\n\n%s\n",
        expected_file_content,
        buffer);

    return AWS_OP_SUCCESS;
}

/*
 * Test cases
 */

#define EXISTING_TEXT "Some existing text\n"
#define SIMPLE_FILE_CONTENT "A few\nlog lines.\n"
static const char *s_combined_text = EXISTING_TEXT SIMPLE_FILE_CONTENT;

AWS_STATIC_STRING_FROM_LITERAL(s_simple_file_content, SIMPLE_FILE_CONTENT);

/*
 * Simple file test
 */
static int s_log_writer_simple_file_test(struct aws_allocator *allocator, void *ctx) {
    (void)ctx;

    struct aws_string *test_file_str = aws_string_new_log_writer_test_filename(allocator);
    const char *test_file_cstr = aws_string_c_str(test_file_str);
    remove(test_file_cstr);

    struct aws_log_writer_file_options options = {.filename = test_file_cstr};

    struct aws_log_writer writer;
    ASSERT_SUCCESS(aws_log_writer_init_file(&writer, allocator, &options));

    ASSERT_SUCCESS(
        do_default_log_writer_test(&writer, test_file_cstr, SIMPLE_FILE_CONTENT, s_simple_file_content, NULL));

    aws_string_destroy(test_file_str);
    return AWS_OP_SUCCESS;
}
AWS_TEST_CASE(test_log_writer_simple_file_test, s_log_writer_simple_file_test);

/*
 * Existing file test (verifies append is being used)
 */
static int s_log_writer_existing_file_test(struct aws_allocator *allocator, void *ctx) {
    (void)ctx;

    struct aws_string *test_file_str = aws_string_new_log_writer_test_filename(allocator);
    const char *test_file_cstr = aws_string_c_str(test_file_str);
    remove(test_file_cstr);

    FILE *fp = aws_fopen(test_file_cstr, "w+");
    fprintf(fp, EXISTING_TEXT);
    fclose(fp);

    struct aws_log_writer_file_options options = {.filename = test_file_cstr};

    struct aws_log_writer writer;
    ASSERT_SUCCESS(aws_log_writer_init_file(&writer, allocator, &options));

    ASSERT_SUCCESS(do_default_log_writer_test(&writer, test_file_cstr, s_combined_text, s_simple_file_content, NULL));

    aws_string_destroy(test_file_str);
    return AWS_OP_SUCCESS;
}
AWS_TEST_CASE(test_log_writer_existing_file_test, s_log_writer_existing_file_test);

/*
 * (Error case) Bad filename test
 */
static int s_log_writer_bad_file_test(struct aws_allocator *allocator, void *ctx) {
    (void)ctx;

    struct aws_log_writer_file_options options = {.filename = "."};

    struct aws_log_writer writer;
    int result = aws_log_writer_init_file(&writer, allocator, &options);
    int aws_error = aws_last_error();

    ASSERT_TRUE(result == AWS_OP_ERR, "Log file open succeeded despite an invalid file name");

#ifdef _WIN32
    ASSERT_TRUE(aws_error == AWS_ERROR_NO_PERMISSION, "File open error was not no permission as expected");
#else
    ASSERT_TRUE(aws_error == AWS_ERROR_FILE_INVALID_PATH, "File open error was not invalid path as expected");
#endif /* _WIN32 */

    return AWS_OP_SUCCESS;
}
AWS_TEST_CASE(test_log_writer_bad_file_test, s_log_writer_bad_file_test);