#include "slide_combine_c.h"
#include <locale.h>

// 提取书签从bkmk文件
ErrorCode extract_bookmarks_from_bkmk(const char* filename, BookmarkItem* bookmarks, int* count) {
    if (!filename || !bookmarks || !count) {
        return ERROR_INVALID_PATH;
    }

    FILE* file = fopen(filename, "rb");
    if (!file) {
        return ERROR_FILE_NOT_FOUND;
    }

    // 读取文件内容到缓冲区
    fseek(file, 0, SEEK_END);
    long file_size = ftell(file);
    fseek(file, 0, SEEK_SET);

    char* buffer = (char*)malloc(file_size + 1);
    if (!buffer) {
        fclose(file);
        return ERROR_MEMORY_ALLOCATION;
    }

    size_t bytes_read = fread(buffer, 1, file_size, file);
    buffer[bytes_read] = '\0';
    fclose(file);

    // 检测并转换编码
    ErrorCode encoding_result = detect_file_encoding(filename, buffer, file_size + 1);
    if (encoding_result != ERROR_NONE) {
        free(buffer);
        return encoding_result;
    }

    // 按行分割内容
    char* line = strtok(buffer, "\r\n");
    *count = 0;

    while (line && *count < MAX_BOOKMARKS) {
        char* trimmed = trim_whitespace(line);
        if (strlen(trimmed) > 0) {
            // 解析书签行
            char* last_space = strrchr(trimmed, ' ');
            if (last_space) {
                *last_space = '\0';

                char* title = trim_whitespace(trimmed);
                char* page = trim_whitespace(last_space + 1);

                if (strlen(title) > 0 && strlen(page) > 0) {
                    strcpy_s(bookmarks[*count].title, sizeof(bookmarks[*count].title), title);
                    strcpy_s(bookmarks[*count].page, sizeof(bookmarks[*count].page), page);
                    (*count)++;
                }
            }
        }
        line = strtok(NULL, "\r\n");
    }

    free(buffer);
    return ERROR_NONE;
}

// 从TXT文件读取元数据
ErrorCode read_metadata_from_txt(const char* filename, DocumentMetadata* metadata) {
    if (!filename || !metadata) {
        return ERROR_INVALID_PATH;
    }

    FILE* file = fopen(filename, "r");
    if (!file) {
        return ERROR_FILE_NOT_FOUND;
    }

    char line[MAX_BUFFER_SIZE];

    // 初始化所有字段为空
    for (int i = 0; i < FIELD_COUNT; i++) {
        metadata->fields[i][0] = '\0';
    }
    metadata->bookmark_count = 0;

    while (fgets(line, sizeof(line), file)) {
        // 移除换行符
        line[strcspn(line, "\r\n")] = '\0';

        char* trimmed = trim_whitespace(line);
        if (strlen(trimmed) == 0) continue;

        // 分割键值对
        char* separator = strchr(trimmed, ':');
        if (!separator) continue;

        *separator = '\0';
        char* key = trim_whitespace(trimmed);
        char* value = trim_whitespace(separator + 1);

        // 查找对应的字段
        for (int i = 0; i < FIELD_COUNT; i++) {
            if (strcmp(key, FIELD_NAMES[i]) == 0) {
                strcpy_s(metadata->fields[i], sizeof(metadata->fields[i]), value);
                break;
            }
        }
    }

    fclose(file);
    return ERROR_NONE;
}

// 创建输出内容
ErrorCode create_output_content(DocumentMetadata* docs, int count, char** output) {
    if (!docs || count <= 0 || !output) {
        return ERROR_INVALID_PATH;
    }

    // 计算总长度
    int total_length = 0;
    for (int i = 0; i < count; i++) {
        for (int j = 0; j < FIELD_COUNT; j++) {
            total_length += strlen(FIELD_NAMES[j]) + strlen(docs[i].fields[j]) + 10;
        }
        total_length += strlen("tableOfContents:") + 10;
        for (int k = 0; k < docs[i].bookmark_count; k++) {
            total_length += strlen(docs[i].bookmarks[k].title) + strlen(docs[i].bookmarks[k].page) + 20;
        }
        total_length += 100; // 分隔符和缓冲
    }

    // 分配内存
    char* result = (char*)malloc(total_length + 1);
    if (!result) {
        return ERROR_MEMORY_ALLOCATION;
    }

    result[0] = '\0';
    char* ptr = result;

    // 生成内容
    for (int i = 0; i < count; i++) {
        if (i > 0) {
            strcat_s(ptr, total_length - strlen(result), " <>\n");
            ptr += strlen(ptr);
        }

        // 添加元数据字段
        for (int j = 0; j < FIELD_COUNT; j++) {
            if (strlen(docs[i].fields[j]) > 0) {
                sprintf_s(ptr, total_length - strlen(result), "%s:%s\n", FIELD_NAMES[j], docs[i].fields[j]);
                ptr += strlen(ptr);
            }
        }

        // 添加书签目录
        if (docs[i].bookmark_count > 0) {
            strcat_s(ptr, total_length - strlen(result), "tableOfContents:\n");
            ptr += strlen(ptr);

            for (int k = 0; k < docs[i].bookmark_count; k++) {
                sprintf_s(ptr, total_length - strlen(result), "%s---------------%s<br/>\n",
                         docs[i].bookmarks[k].title, docs[i].bookmarks[k].page);
                ptr += strlen(ptr);
            }
        }
    }

    *output = result;
    return ERROR_NONE;
}

// 保存内容到文件
ErrorCode save_content_to_file(const char* filename, const char* content) {
    if (!filename || !content) {
        return ERROR_INVALID_PATH;
    }

    FILE* file = fopen(filename, "wb");  // 二进制写入，确保UTF-8 BOM正确
    if (!file) {
        return ERROR_FILE_WRITE;
    }

    // 写入UTF-8 BOM
    const unsigned char bom[] = {0xEF, 0xBB, 0xBF};
    fwrite(bom, 1, 3, file);

    // 写入内容
    size_t content_len = strlen(content);
    size_t written = fwrite(content, 1, content_len, file);

    fclose(file);

    if (written != content_len) {
        return ERROR_FILE_WRITE;
    }

    return ERROR_NONE;
}

// 检测文件编码并转换
ErrorCode detect_file_encoding(const char* filename, char* buffer, int buffer_size) {
    // 简单的编码检测和转换
    // 这里假设文件可能是UTF-8、GBK或GB2312
    // 对于C语言，我们使用Windows API进行转换

    // 检查是否为UTF-8 BOM
    if (buffer_size >= 3 && (unsigned char)buffer[0] == 0xEF &&
        (unsigned char)buffer[1] == 0xBB && (unsigned char)buffer[2] == 0xBF) {
        // 是UTF-8 with BOM，跳过BOM
        memmove(buffer, buffer + 3, buffer_size - 3);
        buffer[buffer_size - 3] = '\0';
        return ERROR_NONE;
    }

    // 尝试用MultiByteToWideChar检测是否为有效UTF-8
    int wide_length = MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, buffer, -1, NULL, 0);
    if (wide_length > 0) {
        // 是有效的UTF-8
        return ERROR_NONE;
    }

    // 尝试用CP_ACP（系统默认编码）
    wide_length = MultiByteToWideChar(CP_ACP, 0, buffer, -1, NULL, 0);
    if (wide_length > 0) {
        // 转换为UTF-8
        wchar_t* wide_buffer = (wchar_t*)malloc(wide_length * sizeof(wchar_t));
        if (!wide_buffer) {
            return ERROR_MEMORY_ALLOCATION;
        }

        MultiByteToWideChar(CP_ACP, 0, buffer, -1, wide_buffer, wide_length);

        int utf8_length = WideCharToMultiByte(CP_UTF8, 0, wide_buffer, -1, NULL, 0, NULL, NULL);
        if (utf8_length > 0 && utf8_length < buffer_size) {
            WideCharToMultiByte(CP_UTF8, 0, wide_buffer, -1, buffer, utf8_length, NULL, NULL);
        }

        free(wide_buffer);
    }

    return ERROR_NONE;
}

// 从文件名提取数字
int extract_number_from_string(const char* str) {
    if (!str) return 0;

    // 使用正则表达式类似的逻辑，查找数字
    const char* p = str;
    while (*p) {
        if (isdigit(*p)) {
            int number = 0;
            while (*p && isdigit(*p)) {
                number = number * 10 + (*p - '0');
                p++;
            }
            return number;
        }
        p++;
    }
    return 0;
}

// 提取文件夹编号
int extract_folder_number(const char* folder_name) {
    if (!folder_name) return 0;

    // 查找第一个数字序列
    const char* p = folder_name;
    while (*p) {
        if (isdigit(*p)) {
            int number = 0;
            const char* start = p;
            while (*p && isdigit(*p)) {
                number = number * 10 + (*p - '0');
                p++;
            }

            // 检查是否是主要的数字（不是年份或其他）
            if (number < 1000) {  // 假设页码不会超过999
                return number;
            }
        }
        p++;
    }
    return 0;
}

// 比较函数用于排序
int compare_bkmk_files(const void* a, const void* b) {
    const char* file_a = *(const char**)a;
    const char* file_b = *(const char**)b;

    // 提取文件夹名称
    char folder_a[MAX_PATH];
    char folder_b[MAX_PATH];

    const char* slash_a = strrchr(file_a, '\\');
    const char* slash_b = strrchr(file_b, '\\');

    if (slash_a) strcpy_s(folder_a, sizeof(folder_a), slash_a + 1);
    else strcpy_s(folder_a, sizeof(folder_a), file_a);

    if (slash_b) strcpy_s(folder_b, sizeof(folder_b), slash_b + 1);
    else strcpy_s(folder_b, sizeof(folder_b), file_b);

    // 提取数字进行比较
    int num_a = extract_folder_number(folder_a);
    int num_b = extract_folder_number(folder_b);

    if (num_a != num_b) {
        return num_a - num_b;
    }

    // 如果数字相同，按字符串比较
    return strcmp(file_a, file_b);
}

// 字符串处理函数
char* trim_whitespace(char* str) {
    if (!str) return NULL;

    // 去除前导空白
    char* start = str;
    while (*start == ' ' || *start == '\t' || *start == '\r' || *start == '\n') {
        start++;
    }

    // 去除尾部空白
    char* end = start + strlen(start) - 1;
    while (end > start && (*end == ' ' || *end == '\t' || *end == '\r' || *end == '\n')) {
        *end = '\0';
        end--;
    }

    // 移动字符串到开始位置
    if (start != str) {
        memmove(str, start, strlen(start) + 1);
    }

    return str;
}