#include "../CgeFs.h"
#include <windows.h>
#include <string.h>

static int utf8ToWchar(const char *utf8, wchar_t *out, int size) {
    int len;

    if (!utf8 || !out || size <= 0)
        return 0;

    len = MultiByteToWideChar(CP_UTF8, 0, utf8, -1, out, size);
    if (len <= 0 || len > size) {
        out[0] = L'\0';
        return 0;
    }

    return 1;
}

static int mapWinError(DWORD err) {
    switch (err) {
    case ERROR_FILE_NOT_FOUND:
    case ERROR_PATH_NOT_FOUND:
        return CGE_FS_ENOENT;

    case ERROR_ALREADY_EXISTS:
        return CGE_FS_EEXIST;

    case ERROR_ACCESS_DENIED:
        return CGE_FS_EACCES;

    case ERROR_DIRECTORY:
        return CGE_FS_ENOTDIR;

    case ERROR_TOO_MANY_OPEN_FILES:
        return CGE_FS_EMFILE;

    case ERROR_FILENAME_EXCED_RANGE:
        return CGE_FS_ENAMETOOLONG;

    default:
        return CGE_FS_EUNKNOWN;
    }
}

static uint64_t fileTimeToUint64(const FILETIME *ft) {
    ULARGE_INTEGER u;
    u.LowPart = ft->dwLowDateTime;
    u.HighPart = ft->dwHighDateTime;
    return u.QuadPart / 10000000ULL - 11644473600ULL;
}

int CgeFsStat(const char *path, CgeFsInfo *info, int *result) {
    wchar_t wpath[MAX_PATH];
    WIN32_FIND_DATAW fd;
    HANDLE handle;
    const char *p;
    const char *base;

    if (!utf8ToWchar(path, wpath, MAX_PATH)) {
        if (result)
            *result = CGE_FS_EUNKNOWN;
        return 0;
    }

    handle = FindFirstFileW(wpath, &fd);
    if (handle == INVALID_HANDLE_VALUE) {
        if (result)
            *result = mapWinError(GetLastError());
        return 0;
    }

    base = NULL;
    for (p = path; *p; p++)
        if (*p == '/' || *p == '\\') base = p + 1;

    if (!base)
        base = path;

    strncpy(info->name, base, CGE_FS_NAME_MAX - 1);
    info->name[CGE_FS_NAME_MAX - 1] = '\0';
    info->type = (fd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) ? CGE_FS_DIR : CGE_FS_FILE;
    info->size = ((uint64_t)fd.nFileSizeHigh << 32) | fd.nFileSizeLow;
    info->mtime = (uint64_t)(fileTimeToUint64(&fd.ftLastWriteTime));

    FindClose(handle);
    return 1;
}

int CgeFsDelete(const char *path, int *result) {
    wchar_t wpath[MAX_PATH];

    if (!utf8ToWchar(path, wpath, MAX_PATH)) {
        if (result)
            *result = CGE_FS_EUNKNOWN;
        return 0;
    }

    if (DeleteFileW(wpath) == 0) {
        if (result)
            *result = mapWinError(GetLastError());
        return 0;
    }
    return 1;
}

int CgeFsRename(const char *from, const char *to, int *result) {
    wchar_t wfrom[MAX_PATH], wto[MAX_PATH];

    if (!utf8ToWchar(from, wfrom, MAX_PATH)) {
        if (result)
            *result = CGE_FS_EUNKNOWN;
        return 0;
    }
    if (!utf8ToWchar(to, wto, MAX_PATH)) {
        if (result)
            *result = CGE_FS_EUNKNOWN;
        return 0;
    }

    if (MoveFileExW(wfrom, wto, MOVEFILE_REPLACE_EXISTING) == 0) {
        if (result)
            *result = mapWinError(GetLastError());
        return 0;
    }
    return 1;
}

int CgeFsCopy(const char *from, const char *to, int *result) {
    wchar_t wfrom[MAX_PATH], wto[MAX_PATH];

    if (!utf8ToWchar(from, wfrom, MAX_PATH)) {
        if (result)
            *result = CGE_FS_EUNKNOWN;
        return 0;
    }
    if (!utf8ToWchar(to, wto, MAX_PATH)) {
        if (result)
            *result = CGE_FS_EUNKNOWN;
        return 0;
    }

    if (CopyFileW(wfrom, wto, FALSE) == 0) {
        if (result)
            *result = mapWinError(GetLastError());
        return 0;
    }
    return 1;
}