-- Check if given table is an array
function is_array(x)
    if #x > 0 then
        return true
    end
    for k, v in pairs(x) do
        return false
    end
    return true
end

-- Get entry-point and filename from `entry-point:filename` path 
function parse_path(path)
    local index = string.find(path, ':')
    if index == nil then
        error("invalid path syntax (':' missing)")
    end
    return string.sub(path, 1, index-1), string.sub(path, index+1, -1)
end

function pack.is_installed(packid)
    return file.isfile(packid..":package.json")
end

function pack.data_file(packid, name)
    file.mkdirs("world:data/"..packid)
    return "world:data/"..packid.."/"..name
end

function pack.shared_file(packid, name)
    file.mkdirs("config:"..packid)
    return "config:"..packid.."/"..name
end


function timeit(iters, func, ...)
    local tm = time.uptime()
    for i=1,iters do
        func(...)
    end
    print("[time mcs]", (time.uptime()-tm) * 1000000)
end

----------------------------------------------

function math.clamp(_in, low, high)
    return math.min(math.max(_in, low), high)
end

function math.rand(low, high)
    return low + (high - low) * math.random()
end

function math.normalize(num, conf)
    conf = conf or 1

    return (num / conf) % 1
end

function math.round(num, places)
    places = places or 0

    local mult = 10 ^ places
    return math.floor(num * mult + 0.5) / mult
end

----------------------------------------------

function table.copy(t)
    local copied = {}

    for k, v in pairs(t) do
        copied[k] = v
    end

    return copied
end

function table.deep_copy(t)
    local copied = {}

    for k, v in pairs(t) do
        if type(v) == "table" then
            copied[k] = table.deep_copy(v)
        else
            copied[k] = v
        end
    end

    return setmetatable(copied, getmetatable(t))
end

function table.count_pairs(t)
    local count = 0

    for k, v in pairs(t) do
        count = count + 1
    end

    return count
end

function table.random(t)
    return t[math.random(1, #t)]
end

function table.shuffle(t)
    for i = #t, 2, -1 do
        local j = math.random(i)
        t[i], t[j] = t[j], t[i]
    end

    return t
end

----------------------------------------------

local pattern_escape_replacements = {
    ["("] = "%(",
    [")"] = "%)",
    ["."] = "%.",
    ["%"] = "%%",
    ["+"] = "%+",
    ["-"] = "%-",
    ["*"] = "%*",
    ["?"] = "%?",
    ["["] = "%[",
    ["]"] = "%]",
    ["^"] = "%^",
    ["$"] = "%$",
    ["\0"] = "%z"
}

function string.pattern_safe(str)
    return string.gsub(str, ".", pattern_escape_replacements)
end

local string_sub = string.sub
local string_find = string.find
local string_len = string.len
function string.explode(separator, str, withpattern)
    if (withpattern == nil) then withpattern = false end

    local ret = {}
    local current_pos = 1

    for i = 1, string_len(str) do
        local start_pos, end_pos = string_find(
            str, separator, current_pos, not withpattern)
        if (not start_pos) then break end
        ret[i] = string_sub(str, current_pos, start_pos - 1)
        current_pos = end_pos + 1
    end

    ret[#ret + 1] = string_sub(str, current_pos)

    return ret
end

function string.split(str, delimiter)
    return string.explode(delimiter, str)
end

function string.formatted_time(seconds, format)
    if (not seconds) then seconds = 0 end
    local hours = math.floor(seconds / 3600)
    local minutes = math.floor((seconds / 60) % 60)
    local millisecs = (seconds - math.floor(seconds)) * 1000
    seconds = math.floor(seconds % 60)

    if (format) then
        return string.format(format, minutes, seconds, millisecs)
    else
        return { h = hours, m = minutes, s = seconds, ms = millisecs }
    end
end

function string.replace(str, tofind, toreplace)
    local tbl = string.explode(tofind, str)
    if (tbl[1]) then return table.concat(tbl, toreplace) end
    return str
end

function string.trim(s, char)
    if char then char = string.pattern_safe(char) else char = "%s" end
    return string.match(s, "^" .. char .. "*(.-)" .. char .. "*$") or s
end

function string.trim_right(s, char)
    if char then char = string.pattern_safe(char) else char = "%s" end
    return string.match(s, "^(.-)" .. char .. "*$") or s
end

function string.trim_left(s, char)
    if char then char = string.pattern_safe(char) else char = "%s" end
    return string.match(s, "^" .. char .. "*(.+)$") or s
end

string.lower = utf8.lower
string.upper = utf8.upper
string.escape = utf8.escape

local meta = getmetatable("")

function meta:__index(key)
    local val = string[key]
    if (val ~= nil) then
        return val
    elseif (tonumber(key)) then
        return string.sub(self, key, key)
    end
end

function string.starts_with(str, start)
    return string.sub(str, 1, string.len(start)) == start
end

function string.ends_with(str, endStr)
    return endStr == "" or string.sub(str, -string.len(endStr)) == endStr
end

function table.has(t, x)
    for i,v in ipairs(t) do
        if v == x then
            return true
        end
    end
    return false
end

function table.index(t, x)
    for i,v in ipairs(t) do
        if v == x then
            return i
        end
    end
    return -1
end

function table.remove_value(t, x)
    local index = table.index(t, x)
    if index ~= -1 then
        table.remove(t, index)
    end
end

function table.tostring(t)
    local s = '['
    for i,v in ipairs(t) do
        s = s..tostring(v)
        if i < #t then
            s = s..', '
        end
    end
    return s..']'
end

function file.readlines(path)
    local str = file.read(path)
    local lines = {}
    for s in str:gmatch("[^\r\n]+") do
        table.insert(lines, s)
    end
    return lines
end

function debug.get_traceback(start)
    local frames = {}
    local n = 2 + (start or 0)
    while true do
        local info = debug.getinfo(n)
        if info then
            table.insert(frames, info)
        else
            return frames
        end
        n = n + 1
    end
end

package = {
    loaded = {}
}
local __cached_scripts = {}
local __warnings_hidden = {}

function on_deprecated_call(name, alternatives)
    if __warnings_hidden[name] then
        return
    end
    __warnings_hidden[name] = true
    events.emit("core:warning", "deprecated call", name, debug.get_traceback(2))
    if alternatives then
        debug.warning("deprecated function called ("..name.."), use "..
            alternatives.." instead\n"..debug.traceback())
    else
        debug.warning("deprecated function called ("..name..")\n"..debug.traceback())
    end
end

-- Load script with caching
--
-- path - script path `contentpack:filename`. 
--     Example `base:scripts/tests.lua`
--
-- nocache - ignore cached script, load anyway
function __load_script(path, nocache)
    local packname, filename = parse_path(path)

    -- __cached_scripts used in condition because cached result may be nil
    if not nocache and __cached_scripts[path] ~= nil then
        return package.loaded[path]
    end
    if not file.isfile(path) then
        error("script '"..filename.."' not found in '"..packname.."'")
    end

    local script, err = load(file.read(path), path)
    if script == nil then
        error(err)
    end
    local result = script()
    if not nocache then
        __cached_scripts[path] = script
        package.loaded[path] = result
    end
    return result
end

function require(path)
    if not string.find(path, ':') then
        local prefix, _ = parse_path(debug.getinfo(2).source)
        return require(prefix..':'..path)
    end
    local prefix, file = parse_path(path)
    return __load_script(prefix..":modules/"..file..".lua")
end

function __scripts_cleanup()
    debug.log("cleaning scripts cache")
    for k, v in pairs(__cached_scripts) do
        local packname, _ = parse_path(k)
        if packname ~= "core" then
            debug.log("unloaded "..k)
            __cached_scripts[k] = nil
            package.loaded[k] = nil
        end
    end
end

function __vc__error(msg, frame)
    if events then
        events.emit("core:error", msg, debug.get_traceback(1))
    end
    return debug.traceback(msg, frame)
end

function __vc_warning(msg, detail, n)
    if events then
        events.emit(
            "core:warning", msg, detail, debug.get_traceback(1 + (n or 0)))
    end
end