local icons = require("lib.utils.sprite_atlas").load(Tree.assets.files.dev_icons)
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 UI_SCALE = require "lib.simple_ui.level.scale"

--- @class SkillButton : UIElement
--- @field hovered boolean
--- @field selected boolean
--- @field onClick function?
--- @field icon? string
local skillButton = setmetatable({}, Element)
skillButton.__index = skillButton

function skillButton:update(dt)
    if not self.icon then return end
    local mx, my = love.mouse.getPosition()
    if self:hitTest(mx, my) then
        self.hovered = true
        if Tree.controls:isJustPressed("select") then
            if self.onClick then self.onClick() end
            Tree.controls:consume("select")
        end
    else
        self.hovered = false
    end
end

function skillButton:draw()
    love.graphics.setLineWidth(2)


    if not self.icon then
        love.graphics.setColor(0.05, 0.05, 0.05)
        love.graphics.rectangle("fill", self.bounds.x, self.bounds.y, self.bounds.width, self.bounds.height)
        self:drawBorder("inner")
        return
    end

    if self.selected then
        love.graphics.setColor(0.3, 1, 0.3)
    elseif self.hovered then
        love.graphics.setColor(0.7, 1, 0.7)
    else
        love.graphics.setColor(1, 1, 1)
    end

    local quad = icons:pickQuad(self.icon)
    love.graphics.push()
    love.graphics.translate(self.bounds.x, self.bounds.y)
    love.graphics.scale(self.bounds.width / icons.tileSize, self.bounds.height / icons.tileSize)
    love.graphics.draw(icons.atlas, quad)
    love.graphics.pop()

    self:drawBorder("inner")
end

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

--- @class SkillRow : UIElement
--- @field characterId Id
--- @field selected SkillButton?
--- @field animationNode AnimationNode
--- @field state "show" | "idle" | "hide"
--- @field children SkillButton[]
local skillRow = setmetatable({}, Element)
skillRow.__index = skillRow

--- @param characterId Id
--- @return SkillRow
function skillRow.new(characterId)
    local t = {
        characterId = characterId,
        state = "show",
        children = {}
    }

    setmetatable(t, skillRow)

    local char = Tree.level.characters[characterId]
    char:try(Tree.behaviors.spellcaster, function(behavior)
        for i, spell in ipairs(behavior.spellbook) do
            local skb = skillButton:new { icon = spell.tag }
            skb.onClick = function()
                if t.state ~= "idle" then return end
                skb.selected = not skb.selected
                if t.selected then t.selected.selected = false end
                t.selected = skb

                if not behavior.cast then
                    behavior.cast = behavior.spellbook[i]
                    behavior.state = "casting"
                else
                    behavior.state = "idle"
                    behavior.cast = nil
                end
            end
            t.children[i] = skb
        end
    end)

    for i = #t.children + 1, 7, 1 do
        t.children[i] = skillButton:new {}
    end

    return t
end

function skillRow:show()
    AnimationNode {
        function(animationNode)
            if self.animationNode then self.animationNode:finish() end
            self.animationNode = animationNode
            self.state = "show"
        end,
        duration = 300,
        onEnd = function()
            self.state = "idle"
        end,
        easing = easing.easeOutCubic
    }:run()
end

function skillRow:hide()
    AnimationNode {
        function(animationNode)
            if self.animationNode then self.animationNode:finish() end
            self.animationNode = animationNode
            self.state = "hide"
        end,
        duration = 300,
        easing = easing.easeOutCubic
    }:run()
end

function skillRow:update(dt)
    if self.animationNode then self.animationNode:update(dt) end

    local iconSize = 64 * UI_SCALE
    local screenW, screenH = love.graphics.getDimensions()
    local padding, margin = 8, 4
    local count = #self.children -- слоты под скиллы

    self.bounds = Rect {
        width = iconSize * count + (count + 1) * margin,
        height = iconSize + 2 * margin,
    }
    self.bounds.y = screenH - self.bounds.height - padding -- отступ снизу
    self.bounds.x = screenW / 2 - self.bounds.width / 2

    for i, skb in ipairs(self.children) do
        skb.bounds = Rect { x = self.bounds.x + margin + (i - 1) * (iconSize + margin), -- друг за другом, включая первый отступ от границы
            y = self.bounds.y + margin, height = iconSize, width = iconSize }
        skb:update(dt)
    end
end

local c = love.graphics.newCanvas(1280, 720) --- @TODO: выставлять канвасу правильный размер в зависимости от окна

function skillRow:draw()
    love.graphics.setCanvas({ c, stencil = true })
    love.graphics.clear()
    love.graphics.setColor(1, 1, 1)

    -- сначала иконки скиллов
    for _, skb in ipairs(self.children) do
        skb:draw()
    end

    -- маска для вырезов под иконки
    love.graphics.setShader(Tree.assets.files.shaders.alpha_mask)
    love.graphics.stencil(function()
        local mask = Tree.assets.files.masks.rrect32
        local maskSize = mask:getWidth()
        for _, skb in ipairs(self.children) do
            love.graphics.draw(mask, skb.bounds.x, skb.bounds.y, 0,
                skb.bounds.width / maskSize, skb.bounds.height / maskSize)
        end
    end, "replace", 1)
    love.graphics.setShader()

    -- дальше рисуем панель, перекрывая иконки
    love.graphics.setStencilTest("less", 1)
    -- шум
    love.graphics.setShader(Tree.assets.files.shaders.soft_uniform_noise)
    love.graphics.rectangle("fill", self.bounds.x, self.bounds.y, self.bounds.width, self.bounds.height)
    love.graphics.setShader()

    -- фон
    love.graphics.setColor(38 / 255, 50 / 255, 56 / 255)
    love.graphics.setBlendMode("multiply", "premultiplied")
    love.graphics.rectangle("fill", self.bounds.x, self.bounds.y, self.bounds.width, self.bounds.height)
    love.graphics.setBlendMode("alpha")

    --граница
    self:drawBorder("outer")

    love.graphics.setStencilTest()

    --затенение
    self:drawGradientOverlay()

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

    local alpha = 1
    if self.state == "show" then
        alpha = self.animationNode:getValue()
    elseif self.state == "hide" then
        alpha = 1 - self.animationNode:getValue()
    end
    love.graphics.setColor(1, 1, 1, alpha)
    love.graphics.draw(c)
end

return skillRow.new