require "common.globals"
require "api.logging"

---@class FileSys
local FileSys = {
    __name = "FileSys",
    sep = "/"
}

setmetatable(FileSys, FileSys)

---Return a normalized absolutized version of `path`
---@param path string
---@return string
function FileSys.abspath(path)
    return FileSys.normpath(FileSys.join(FileSys.getcwd(), path))
end

---Return the base name of `path`
---@param path string
---@return string
function FileSys.basename(path)
    return string.sub(path, string.rfind(path, FileSys.sep, 1, true) + 1)
end

---Return the directory name of `path`
---@param path string
---@return string
function FileSys.dirname(path)
    return FileSys.split(path)[1]
end

---Return true if `path` refers to an existing path
---@param path string
---@return boolean, string?
function FileSys.exists(path)
    local ok, err, code = os.rename(path, path)
    if not ok then
        DetailedLog("err: "..err..", code: "..code, game.LOGGER_DEBUG)
        if code == 13 then
            -- Permission denied, but it exists
            return true
        end
    end
    return ok, err
end

---Returns a path relative to the current working directory from a texture path
---@param path string # must be a path accepted by game.CreateSkinImage and such
---@return string
function FileSys.fromTexturePath(path)
    --skins/<skin>/textures/<path>
    local relpath = FileSys.join("skins", game.GetSkin(), "textures", FileSys.normpath(path))

    if not FileSys.exists(FileSys.join(FileSys.getcwd(), relpath)) then
        DetailedLog("'"..relpath.."' does not exist", game.LOGGER_ERROR)
    end

    return relpath
end

---Return a string representing the current working directory
---@return string
function FileSys.getcwd()
    error(FileSys.__name .. ".getcwd() : Not Implemented")
end

---Join one or more path components with the platform specific separator
---@param path string
---@param ... string
---@return string
function FileSys.join(path, ...)
    local vargs = { select(1, ...) }
    local joinedpath = path

    for _, value in ipairs(vargs) do
        joinedpath = joinedpath .. FileSys.sep .. value
    end

    return joinedpath
end

---Normalize `path`, collapse redundant separators and up references
---@param path string
---@param overrideSep? string
---@return string
function FileSys.normpath(path, overrideSep)
    local sep = overrideSep or FileSys.sep

    --remove multiple slashes
    path = path:gsub("("..sep..")"..sep.."+", "%1")

    --remove './'
    path = path:gsub("%."..sep, "")

    --remove all up references
    local count = 0
    local upRefPattern = "%w+"..sep.."%.%."..sep
    repeat
        path, count = path:gsub(upRefPattern, "")
    until count == 0

    --remove last slash
    path = path:gsub("(.-)"..sep.."$", "%1")

    return path
end

---Return a relative filepath to `path`, optionally relative to `relativeTo`
---@param path string
---@param relativeTo? string
---@return string
function FileSys.relpath(path, relativeTo)
    relativeTo = relativeTo or FileSys.getcwd()
    path = path:sub(path:find(relativeTo, 1, true)[2] + 1)
    return path
end

---Return a list of files and directory names in `path`
---@param path string
---@return string[]
function FileSys.scandir(path)
    error(FileSys.__name .. ".scandir() : Not Implemented")
end

---Split `path` to (head, tail), tail is the last component, head is everything else
---@param path string
---@return string, string
function FileSys.split(path)
    local lastSep = path:rfind(FileSys.sep, 1, true)
    return path:sub(1, lastSep), path:sub(lastSep + 1)
end

---Split `path` to (root, ext), such that `root + ext == path`, ext is either empty or starts with a '.'
---@param path string
---@return string, string
function FileSys.splitext(path)
    local lastSep = path:rfind(".", 1, true)
    return path:sub(1, lastSep - 1), path:sub(lastSep)
end

return FileSys