local easing = require "lib.utils.easing"
local AnimationNode = require "lib.animation_node"
local Element = require "lib.simple_ui.element"
local Rect = require "lib.simple_ui.rect"
local SkillRow = require "lib.simple_ui.level.skill_row"

--- @class BarElement : UIElement
--- @field getter fun() : number
--- @field value number
--- @field maxValue number
local barElement = setmetatable({}, Element)
barElement.__index = barElement

function barElement:update(dt)
    local val = self.getter()
    self.value = val < 0 and 0 or val > self.maxValue and self.maxValue or val
end

function barElement:draw()
    love.graphics.push()
    love.graphics.applyTransform(self.transform)

    love.graphics.setColor(1, 1, 1)

    love.graphics.rectangle("fill", self.bounds.x, self.bounds.y, self.bounds.width * self.value / self.maxValue,
        self.bounds.height)

    love.graphics.setColor(1, 1, 1)
    love.graphics.pop()
end

--- @class BottomBars : UIElement
--- @field children BarElement[]
local bottomBars = setmetatable({}, Element)
bottomBars.__index = bottomBars;

--- @param cid Id
function bottomBars.new(cid)
    local t = setmetatable({}, bottomBars)

    t.children = {
        barElement:new {
            getter = function()
                local char = Tree.level.characters[cid]
                return char:try(Tree.behaviors.stats, function(stats)
                    return stats.hp or 0
                end)
            end,
            maxValue = 20
        },

        barElement:new {
            getter = function()
                local char = Tree.level.characters[cid]
                return char:try(Tree.behaviors.stats, function(stats)
                    return stats.mana or 0
                end)
            end,
            maxValue = 10
        }
    }

    return t
end

function bottomBars:update(dt)
    local padding = 8
    local screenW, screenH = love.graphics.getDimensions()
    self.bounds = Rect {
        height = 40 + 2 * padding,
        width = screenW * 0.25,
        y = screenH - 64 - 1 - 2 * padding - 40
    }

    self.transform = love.math.newTransform():translate(-self.bounds.width / 2 + screenW / 2, self.bounds.y)

    for i = 1, #self.children do
        self.children[i].bounds = Rect {
            width = screenW * 0.25,
            height = 20
        }
        self.children[i].transform = self.transform:clone():translate(0,
            self.children[i].bounds.height * (i - 1) + (i - 1) * padding)
    end


    for _, el in ipairs(self.children) do
        el:update(dt)
    end
end

function bottomBars:draw()
    for _, el in ipairs(self.children) do
        el:draw()
    end
end

local layout = {}
function layout:update(dt)
    local cid = Tree.level.selector:selected()
    if cid then
        self.skillRow = SkillRow(cid)
        self.skillRow:show()
        -- self.bottomBars = bottomBars.new(cid)
    elseif Tree.level.selector:deselected() then
        self.skillRow:hide()
        --  self.bottomBars = nil
    end
    if self.skillRow then self.skillRow:update(dt) end
    -- if self.bottomBars then self.bottomBars:update(dt) end
end

function layout:draw()
    if self.skillRow then self.skillRow:draw() end
    -- if self.bottomBars then self.bottomBars:draw() end
end

return layout