-------------------------------------------
-- @author https://github.com/Kasper24
-- @copyright 2021-2025 Kasper24
-------------------------------------------
-- easing
-- Adapted from https://github.com/EmmanuelOga/easing. See LICENSE.txt for credits.
-- For all easing functions:
-- t = time == how much time has to pass for the tweening to complete
-- b = begin == starting property value
-- c = change == ending - beginning
-- d = duration == running time. How much time has passed *right now*
local gobject = require("gears.object")
local gtable = require("gears.table")
local Color = require("external.lua-color")
local tostring = tostring
local assert = assert
local table = table
local pairs = pairs
local error = error

local type = type

local tween = {
    _VERSION = 'tween 2.1.1',
    _DESCRIPTION = 'tweening for lua',
    _URL = 'https://github.com/kikito/tween.lua',
    _LICENSE = [[
    MIT LICENSE
    Copyright (c) 2014 Enrique García Cota, Yuichi Tateno, Emmanuel Oga
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the
    "Software"), to deal in the Software without restriction, including
    without limitation the rights to use, copy, modify, merge, publish,
    distribute, sublicense, and/or sell copies of the Software, and to
    permit persons to whom the Software is furnished to do so, subject to
    the following conditions:
    The above copyright notice and this permission notice shall be included
    in all copies or substantial portions of the Software.
    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
    OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
    IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
    CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
    TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
    SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  ]]
}

local pow, sin, cos, pi, sqrt, abs, asin = math.pow, math.sin, math.cos, math.pi, math.sqrt, math.abs, math.asin

-- linear
local function linear(t, b, c, d)
    return c * t / d + b
end

-- quad
local function inQuad(t, b, c, d)
    return c * pow(t / d, 2) + b
end
local function outQuad(t, b, c, d)
    t = t / d
    return -c * t * (t - 2) + b
end
local function inOutQuad(t, b, c, d)
    t = t / d * 2
    if t < 1 then
        return c / 2 * pow(t, 2) + b
    end
    return -c / 2 * ((t - 1) * (t - 3) - 1) + b
end
local function outInQuad(t, b, c, d)
    if t < d / 2 then
        return outQuad(t * 2, b, c / 2, d)
    end
    return inQuad((t * 2) - d, b + c / 2, c / 2, d)
end

-- cubic
local function inCubic(t, b, c, d)
    return c * pow(t / d, 3) + b
end
local function outCubic(t, b, c, d)
    return c * (pow(t / d - 1, 3) + 1) + b
end
local function inOutCubic(t, b, c, d)
    t = t / d * 2
    if t < 1 then
        return c / 2 * t * t * t + b
    end
    t = t - 2
    return c / 2 * (t * t * t + 2) + b
end
local function outInCubic(t, b, c, d)
    if t < d / 2 then
        return outCubic(t * 2, b, c / 2, d)
    end
    return inCubic((t * 2) - d, b + c / 2, c / 2, d)
end

-- quart
local function inQuart(t, b, c, d)
    return c * pow(t / d, 4) + b
end
local function outQuart(t, b, c, d)
    return -c * (pow(t / d - 1, 4) - 1) + b
end
local function inOutQuart(t, b, c, d)
    t = t / d * 2
    if t < 1 then
        return c / 2 * pow(t, 4) + b
    end
    return -c / 2 * (pow(t - 2, 4) - 2) + b
end
local function outInQuart(t, b, c, d)
    if t < d / 2 then
        return outQuart(t * 2, b, c / 2, d)
    end
    return inQuart((t * 2) - d, b + c / 2, c / 2, d)
end

-- quint
local function inQuint(t, b, c, d)
    return c * pow(t / d, 5) + b
end
local function outQuint(t, b, c, d)
    return c * (pow(t / d - 1, 5) + 1) + b
end
local function inOutQuint(t, b, c, d)
    t = t / d * 2
    if t < 1 then
        return c / 2 * pow(t, 5) + b
    end
    return c / 2 * (pow(t - 2, 5) + 2) + b
end
local function outInQuint(t, b, c, d)
    if t < d / 2 then
        return outQuint(t * 2, b, c / 2, d)
    end
    return inQuint((t * 2) - d, b + c / 2, c / 2, d)
end

-- sine
local function inSine(t, b, c, d)
    return -c * cos(t / d * (pi / 2)) + c + b
end
local function outSine(t, b, c, d)
    return c * sin(t / d * (pi / 2)) + b
end
local function inOutSine(t, b, c, d)
    return -c / 2 * (cos(pi * t / d) - 1) + b
end
local function outInSine(t, b, c, d)
    if t < d / 2 then
        return outSine(t * 2, b, c / 2, d)
    end
    return inSine((t * 2) - d, b + c / 2, c / 2, d)
end

-- expo
local function inExpo(t, b, c, d)
    if t == 0 then
        return b
    end
    return c * pow(2, 10 * (t / d - 1)) + b - c * 0.001
end
local function outExpo(t, b, c, d)
    if t == d then
        return b + c
    end
    return c * 1.001 * (-pow(2, -10 * t / d) + 1) + b
end
local function inOutExpo(t, b, c, d)
    if t == 0 then
        return b
    end
    if t == d then
        return b + c
    end
    t = t / d * 2
    if t < 1 then
        return c / 2 * pow(2, 10 * (t - 1)) + b - c * 0.0005
    end
    return c / 2 * 1.0005 * (-pow(2, -10 * (t - 1)) + 2) + b
end
local function outInExpo(t, b, c, d)
    if t < d / 2 then
        return outExpo(t * 2, b, c / 2, d)
    end
    return inExpo((t * 2) - d, b + c / 2, c / 2, d)
end

-- circ
local function inCirc(t, b, c, d)
    return (-c * (sqrt(1 - pow(t / d, 2)) - 1) + b)
end
local function outCirc(t, b, c, d)
    return (c * sqrt(1 - pow(t / d - 1, 2)) + b)
end
local function inOutCirc(t, b, c, d)
    t = t / d * 2
    if t < 1 then
        return -c / 2 * (sqrt(1 - t * t) - 1) + b
    end
    t = t - 2
    return c / 2 * (sqrt(1 - t * t) + 1) + b
end
local function outInCirc(t, b, c, d)
    if t < d / 2 then
        return outCirc(t * 2, b, c / 2, d)
    end
    return inCirc((t * 2) - d, b + c / 2, c / 2, d)
end

-- elastic
local function calculatePAS(p, a, c, d)
    p, a = p or d * 0.3, a or 0
    if a < abs(c) then
        return p, c, p / 4
    end -- p, a, s
    return p, a, p / (2 * pi) * asin(c / a) -- p,a,s
end
local function inElastic(t, b, c, d, a, p)
    local s
    if t == 0 then
        return b
    end
    t = t / d
    if t == 1 then
        return b + c
    end
    p, a, s = calculatePAS(p, a, c, d)
    t = t - 1
    return -(a * pow(2, 10 * t) * sin((t * d - s) * (2 * pi) / p)) + b
end
local function outElastic(t, b, c, d, a, p)
    local s
    if t == 0 then
        return b
    end
    t = t / d
    if t == 1 then
        return b + c
    end
    p, a, s = calculatePAS(p, a, c, d)
    return a * pow(2, -10 * t) * sin((t * d - s) * (2 * pi) / p) + c + b
end
local function inOutElastic(t, b, c, d, a, p)
    local s
    if t == 0 then
        return b
    end
    t = t / d * 2
    if t == 2 then
        return b + c
    end
    p, a, s = calculatePAS(p, a, c, d)
    t = t - 1
    if t < 0 then
        return -0.5 * (a * pow(2, 10 * t) * sin((t * d - s) * (2 * pi) / p)) + b
    end
    return a * pow(2, -10 * t) * sin((t * d - s) * (2 * pi) / p) * 0.5 + c + b
end
local function outInElastic(t, b, c, d, a, p)
    if t < d / 2 then
        return outElastic(t * 2, b, c / 2, d, a, p)
    end
    return inElastic((t * 2) - d, b + c / 2, c / 2, d, a, p)
end

-- back
local function inBack(t, b, c, d, s)
    s = s or 1.70158
    t = t / d
    return c * t * t * ((s + 1) * t - s) + b
end
local function outBack(t, b, c, d, s)
    s = s or 1.70158
    t = t / d - 1
    return c * (t * t * ((s + 1) * t + s) + 1) + b
end
local function inOutBack(t, b, c, d, s)
    s = (s or 1.70158) * 1.525
    t = t / d * 2
    if t < 1 then
        return c / 2 * (t * t * ((s + 1) * t - s)) + b
    end
    t = t - 2
    return c / 2 * (t * t * ((s + 1) * t + s) + 2) + b
end
local function outInBack(t, b, c, d, s)
    if t < d / 2 then
        return outBack(t * 2, b, c / 2, d, s)
    end
    return inBack((t * 2) - d, b + c / 2, c / 2, d, s)
end

-- bounce
local function outBounce(t, b, c, d)
    t = t / d
    if t < 1 / 2.75 then
        return c * (7.5625 * t * t) + b
    end
    if t < 2 / 2.75 then
        t = t - (1.5 / 2.75)
        return c * (7.5625 * t * t + 0.75) + b
    elseif t < 2.5 / 2.75 then
        t = t - (2.25 / 2.75)
        return c * (7.5625 * t * t + 0.9375) + b
    end
    t = t - (2.625 / 2.75)
    return c * (7.5625 * t * t + 0.984375) + b
end
local function inBounce(t, b, c, d)
    return c - outBounce(d - t, 0, c, d) + b
end
local function inOutBounce(t, b, c, d)
    if t < d / 2 then
        return inBounce(t * 2, 0, c, d) * 0.5 + b
    end
    return outBounce(t * 2 - d, 0, c, d) * 0.5 + c * .5 + b
end
local function outInBounce(t, b, c, d)
    if t < d / 2 then
        return outBounce(t * 2, b, c / 2, d)
    end
    return inBounce((t * 2) - d, b + c / 2, c / 2, d)
end

tween.easing = {
    linear = linear,
    inQuad = inQuad,
    outQuad = outQuad,
    inOutQuad = inOutQuad,
    outInQuad = outInQuad,
    inCubic = inCubic,
    outCubic = outCubic,
    inOutCubic = inOutCubic,
    outInCubic = outInCubic,
    inQuart = inQuart,
    outQuart = outQuart,
    inOutQuart = inOutQuart,
    outInQuart = outInQuart,
    inQuint = inQuint,
    outQuint = outQuint,
    inOutQuint = inOutQuint,
    outInQuint = outInQuint,
    inSine = inSine,
    outSine = outSine,
    inOutSine = inOutSine,
    outInSine = outInSine,
    inExpo = inExpo,
    outExpo = outExpo,
    inOutExpo = inOutExpo,
    outInExpo = outInExpo,
    inCirc = inCirc,
    outCirc = outCirc,
    inOutCirc = inOutCirc,
    outInCirc = outInCirc,
    inElastic = inElastic,
    outElastic = outElastic,
    inOutElastic = inOutElastic,
    outInElastic = outInElastic,
    inBack = inBack,
    outBack = outBack,
    inOutBack = inOutBack,
    outInBack = outInBack,
    inBounce = inBounce,
    outBounce = outBounce,
    inOutBounce = inOutBounce,
    outInBounce = outInBounce
}

-- Private interface
local function copyTables(destination, keysTable, valuesTable)
    valuesTable = valuesTable or keysTable
    local mt = getmetatable(keysTable)
    if mt and getmetatable(destination) == nil then
        setmetatable(destination, mt)
    end

    for k, v in pairs(keysTable) do
        if type(v) == 'table' then
            destination[k] = copyTables({}, v, valuesTable[k])
        else
            destination[k] = valuesTable[k]
        end
    end
    return destination
end

local function checkSubjectAndTargetRecursively(subject, target, path)
    path = path or {}
    local targetType, newPath
    for k, targetValue in pairs(target) do
        targetType, newPath = type(targetValue), copyTables({}, path)
        table.insert(newPath, tostring(k))
        if targetType == 'number' then
            assert(type(subject[k]) == 'number',
                "Parameter '" .. table.concat(newPath, '/') .. "' is missing from subject or isn't a number")
        elseif targetType == 'table' then
            checkSubjectAndTargetRecursively(subject[k], targetValue, newPath)
        else
            assert(targetType == 'number',
                "Parameter '" .. table.concat(newPath, '/') .. "' must be a number or table of numbers")
        end
    end
end

local function checkNewParams(initial, duration, subject, target, easing)
    -- assert(type(initial) == 'number' and duration > 0, "duration must be a positive number. Was " .. tostring(duration))
    -- assert(type(duration) == 'number' and duration > 0, "duration must be a positive number. Was " .. tostring(duration))
    assert(type(easing) == 'function', "easing must be a function. Was " .. tostring(easing))

    if subject and target then
        local tsubject = type(subject)
        assert(tsubject == 'table' or tsubject == 'userdata',
            "subject must be a table or userdata. Was " .. tostring(subject))
        assert(type(target) == 'table', "target must be a table. Was " .. tostring(target))
        checkSubjectAndTargetRecursively(subject, target)
    end
end

local function getEasingFunction(easing)
    easing = easing or "linear"
    if type(easing) == 'string' then
        local name = easing
        easing = tween.easing[name]
        if type(easing) ~= 'function' then
            error("The easing function name '" .. name .. "' is invalid")
        end
    end
    return easing
end

local function performEasingOnSubject(subject, target, initial, clock, duration, easing)
    local t, b, c, d
    for k, v in pairs(target) do
        if type(v) == 'table' then
            performEasingOnSubject(subject[k], v, initial[k], clock, duration, easing)
        else
            t, b, c, d = clock, initial[k], v - initial[k], duration
            subject[k] = easing(t, b, c, d)
        end
    end
end

local function performEasingOnColor(initial, target, clock, duration, easing)
    initial = Color(initial)
    target = Color(target)

    local r = easing(clock, initial.r, target.r - initial.r, duration)
    local g = easing(clock, initial.g, target.g - initial.g, duration)
    local b = easing(clock, initial.b, target.b - initial.b, duration)
    local a = easing(clock, initial.a, target.a - initial.a, duration)

    return tostring(Color({r = r, g = g, b = b, a = a}))
end

local function performEasing(table, initial, target, clock, duration, easing)
    if type(target) == "table" then
        local t, b, c, d
        for k, target in pairs(target) do
            if type(target) == 'table' then
                table[k] = {}
                performEasing(table[k], initial[k], target, clock, duration, easing)
            elseif type(target) == "string" and target:sub(1, 1) =="#" then
                table[k] = performEasingOnColor(initial[k], target, clock, duration, easing)
            else
                t, b, c, d = clock, initial[k], target - initial[k], duration
                table[k] = easing(t, b, c, d)
            end
        end

        return table
    elseif type(target) == "string" and target:sub(1, 1) =="#" then
        return performEasingOnColor(initial, target, clock, duration, easing)
    else
        local t, b, c, d = clock, initial, target - initial, duration
        return easing(t, b, c, d)
    end
end

-- Public interface
local Tween = {}

function Tween:set(clock)
    assert(type(clock) == 'number', "clock must be a positive number or 0")

    if self.subject and self.initial == 0 then
        self.initial = copyTables({}, self.target, self.subject)
    end

    self.clock = clock

    if self.clock <= 0 then
        self.clock = 0
        if self.subject then
            copyTables(self.subject, self.initial)
        end
    elseif self.clock >= self.duration then -- the tween has expired
        self.clock = self.duration

        if self.subject then
            copyTables(self.subject, self.target)
        end
    else
        if self.subject then
            performEasingOnSubject(self.subject, self.target, self.initial, self.clock, self.duration, self.easing)
        else
            local pos = {}
            return performEasing(pos, self.initial, self.target, self.clock, self.duration, self.easing)
        end
    end

    return self.clock >= self.duration
end

function Tween:update(dt)
    assert(type(dt) == 'number', "dt must be a number")
    return self:set(self.clock + dt)
end

function Tween:reset()
    return self:set(0)
end

function tween.new(args)
    args = args or {}

    args.initial = args.initial or 0
    args.subject = args.subject or nil
    args.target = args.target or nil
    args.duration = args.duration or 0
    args.easing = args.easing or nil

    args.easing = getEasingFunction(args.easing)
    checkNewParams(args.initial, args.duration, args.subject, args.target, args.easing)

    local ret = gobject {}
    ret.clock = 0

    gtable.crush(ret, args, true)
    gtable.crush(ret, Tween, true)

    return ret
end

return tween
