local lfs = require("lfs")

local M = {}


-- 创建目录
M.create_dir = function(dirpath)
    -- 检查操作系统类型
    local os_type = package.config:sub(1,1)
    if os_type == "\\" then
        -- Windows 系统
        os.execute("mkdir \"" .. dirpath:gsub("/", "\\") .. "\" /p")
    else
        -- Unix/Linux/Mac 系统
        os.execute("mkdir -p \"" .. dirpath .. "\"")
    end
end
-- 转换为整数
M.tointeger = function(data)
    local num = tonumber(data)
    if num == nil then
        return nil
    end
    return math.floor(num)
end
-- 转为时间戳
M.to_timestamp = function(time_str,pattern)
    if pattern == nil then
        pattern = "(%d+)%-(%d+)%-(%d+)%s+(%d+):(%d+):(%d+)"
    end
    local y, m, d, h, min, s = time_str:match(pattern)
    local timestamp = os.time({
        year = tonumber(y),
        month = tonumber(m),
        day = tonumber(d),
        hour = tonumber(h),
        min = tonumber(min),
        sec = tonumber(s)
    })
    return timestamp 
end
-- 取扩展名
M.ext = function(filepath)
    -- 取扩展名
    return string.match(filepath,"%.([^.]+)$")
end
-- 复制文件
-- 增加第三个参数 replace，是否替换目标文件，默认为 false
M.copy_file = function(src, dst, replace)
    replace = replace or false
    -- 检查目标文件是否存在
    local dst_file = io.open(dst, "r")
    if dst_file ~= nil then
        dst_file:close()
        if not replace then
            return true
        end
    end
    -- 打开源文件
    local file = io.open(src, "rb")
    if not file then
        print("ERR 2,src:",src)
        return false
    end
    local content = file:read("*all")
    file:close()
    -- 写入目标文件
    local file = io.open(dst, "wb")
    if not file then
        print("ERR 3") 
        return false
    end
    file:write(content)
    file:close()
    return true
end
-- 取路径文件名(带扩展名)
M.filename = function(filepath, have_ext)
    local filename = string.match(filepath, "[^/]+$")
    if have_ext == false then
        local name = string.match(filename, "^(.*)%.") -- get name before last dot
        if name ~= nil then
            return name
        else
            return filename -- no extension
        end
    end
    return filename
end
-- 删除文件
M.delete_file = function(filepath)
    if os.remove(fw.website_dir()..filepath) ~= true then
        return false
    end
    return true
end
-- 读取文件内容
M.read_file = function(filepath)
    local file = io.open(filepath, "rb")
    if not file then
        return nil, "无法打开文件: " .. tostring(filepath)
    end
    local content = file:read("*all")
    file:close()
    return content
end

-- 保存内容到文件
M.save_file = function(filepath, content)
    local file = io.open(filepath, "wb")
    if not file then
        return false, "无法打开文件: " .. tostring(filepath)
    end
    file:write(content)
    file:close()
    return true
end
-- 是否存在文件
M.exists_file = function(filepath)
    local file = io.open(filepath, "rb")
    if file then
        file:close()
        return true
    else
        return false
    end
end
-- 取文件大小
M.file_size = function(filepath)
    local file = io.open(filepath, "rb")
    if not file then
        return nil
    end
    local size = file:seek("end")
    file:close()
    return size
end
-- 取近N个月时间
M.recent_months = function(n)
    local mons = {}
    local function format_time(y, m, d, h, i, s)
        return string.format("%04d-%02d-%02d %02d:%02d:%02d", y, m, d, h, i, s)
    end
    local now = os.time()
    local cur = os.date("*t", now)
    for i = n-1, 0, -1 do
        local year = cur.year
        local month = cur.month - i
        while month <= 0 do
            month = month + 12
            year = year - 1
        end
        -- 获取该月第一天与最后一天
        local first_day = format_time(year, month, 1, 0, 0, 0)
        local next_month = month + 1
        local next_year = year
        if next_month > 12 then
            next_month = 1
            next_year = year + 1
        end
        -- next_month 1号的前一天就是当前月最后一天
        local last_day_ts = os.time{year=next_year, month=next_month, day=1, hour=0, min=0, sec=0} - 1
        local last_day_tm = os.date("*t", last_day_ts)
        local last_day = format_time(last_day_tm.year, last_day_tm.month, last_day_tm.day, 23, 59, 59)
        local month_str = string.format("%04d-%02d", year, month)
        table.insert(mons, month_str)
    end
    return mons
end
M.recent_months2 = function(n)
    local mons = {}
    local function format_time(y, m, d, h, i, s)
        return string.format("%04d-%02d-%02d %02d:%02d:%02d", y, m, d, h, i, s)
    end
    local now = os.time()
    local cur = os.date("*t", now)
    for i = n-1, 0, -1 do
        local year = cur.year
        local month = cur.month - i
        while month <= 0 do
            month = month + 12
            year = year - 1
        end
        -- 获取该月第一天与最后一天
        local first_day = format_time(year, month, 1, 0, 0, 0)
        local next_month = month + 1
        local next_year = year
        if next_month > 12 then
            next_month = 1
            next_year = year + 1
        end
        -- next_month 1号的前一天就是当前月最后一天
        local last_day_ts = os.time{year=next_year, month=next_month, day=1, hour=0, min=0, sec=0} - 1
        local last_day_tm = os.date("*t", last_day_ts)
        local last_day = format_time(last_day_tm.year, last_day_tm.month, last_day_tm.day, 23, 59, 59)
        local month_str = string.format("%04d-%02d", year, month)
        table.insert(mons, {
            month = month_str,
            start_time = first_day,
            end_time = last_day
        })
    end
    return mons
end
-- 十六进制转字节数组
M.hex_to_bytes = function(hex_str)
    -- 移除所有非十六进制字符
    hex_str = hex_str:gsub("[^%x]", ""):upper()
    
    -- 补0使长度为偶数
    if #hex_str % 2 == 1 then
        hex_str = "0" .. hex_str
    end
    
    -- 使用 gsub 一次性转换
    return (hex_str:gsub("(%x%x)", function(hex)
        return string.char(tonumber(hex, 16))
    end))
end
--[[
    还原 Redis 字符串（去转义）
    @param value 被转义的字符串
    @return 返回还原后的字符串
]]
M.unescape_value = function(value)
    if value == nil then
        return nil
    end
    local str = tostring(value)
    -- 如果是用双引号包住的，去掉包裹并恢复转义
    if #str >= 2 and string.sub(str,1,1) == "\"" and string.sub(str,-1,-1) == "\"" then
        str = string.sub(str,2,-2)
        str = string.gsub(str, "\\\"", "\"")
        str = string.gsub(str, "\\\\", "\\")
        return str
    end
    return str
end
-- 是否为静态资源扩展名
M.is_static_ext_not_html = function(ext)
    local static_exts = {
        "jpg",
        "jpeg",
        "png",
        "gif",
        "bmp",
        "ico",
        "pdf",
        "doc",
        "docx",
        "xls",
        "xlsx",
        "ppt",
        "pptx",
        "txt",
        "css",
        "js",
        "json",
        "xml",
        "yaml",
        "yml",
        "zip",
        "rar",
        "7z",
        "tar",
        "gz",
        "bz2",
        "xz",
        "mp3",
        "wav",
        "ogg",
        "aac",
        "m4a",
        "mp4",
        "avi",
        "mov",
        "wmv",
        "flv",
        "webm",
        "mkv",
        "avi",
        "mov",
        "wmv",
        "flv",
        "webm",
        "mkv",
    }
    for _, v in ipairs(static_exts) do
        if v == ext then
            return true
        end
    end
    return false
end
-- 遍历目录
M.traverse_dir = function(dirpath)
    local files = {}
    for file in lfs.dir(dirpath) do
        if file ~= "." and file ~= ".." then
            table.insert(files, file)
        end
    end
    return files
end
-- 数组是否一致(不考虑顺序)
-- 只考虑 string 和 number/integer 类型，其它类型忽略
M.array_equal = function(a, b)
    -- 辅助函数：判断是否为有效类型（string 或 number）
    local function is_valid_type(v)
        return type(v) == "string" or type(v) == "number"
    end
    
    -- 统计数组中有效类型元素的值及其出现次数
    local function count_values(arr)
        local counts = {}
        for _, v in ipairs(arr) do
            if is_valid_type(v) then
                local key = tostring(v)  -- 统一转换为字符串作为key
                counts[key] = (counts[key] or 0) + 1
            end
        end
        return counts
    end
    
    -- 统计两个数组的有效元素
    local counts_a = count_values(a)
    local counts_b = count_values(b)
    
    -- 检查 counts_a 中的所有键值对是否在 counts_b 中匹配
    for key, count in pairs(counts_a) do
        if counts_b[key] ~= count then
            return false
        end
    end
    
    -- 检查 counts_b 中的所有键值对是否在 counts_a 中匹配
    for key, count in pairs(counts_b) do
        if counts_a[key] ~= count then
            return false
        end
    end
    
    return true
end
return M