require 'config'
require 'button'

-- Menu state class
---@class MenuState
---@field buttons Button[]
MenuState = {
    buttons = {}
}

-- Factory function
---@param buttons Button[] | nil
---@return MenuState
function MenuState:new( buttons )
    local state = {
        buttons = buttons or MenuState.buttons
    }

    setmetatable( state, { __index = self } )

    return state
end

-- Draw buttons
function MenuState:draw()
    for _, button in ipairs(self.buttons) do
        button:draw()
    end
end

-- Update buttons
---@param dt number
---@param point Point
---@param pressed boolean
function MenuState:update( dt, point, pressed )
    for _, button in pairs(self.buttons) do
        button:update( dt, point, pressed )
    end
end

---@enum MenuStateIndex
MenuStateIndex = {
    start = 'start',
    pause = 'pause',
    levels = 'levels',
    hidden = 'hidden',
    completed = 'completed'
}

local buttonTopPos = Point:new( 240, 120 )
local buttonBotPos = Point:new( 240, 240 )
local buttonSize = Point:new( 320, 80 )

local startButton = Button:new(
    buttonTopPos,
    buttonSize,
    'Start',
    nil,
    nil,
    function()
        Menu.current_state = MenuStateIndex.hidden
        GameGrid = LevelHandler:first()
        Menu.updateCellSize()
    end
)

local exitToMenuButton = Button:new(
    buttonBotPos,
    buttonSize,
    'Return to menu',
    nil,
    nil,
    function()
        Menu.current_state = MenuStateIndex.start
    end
)

local exitGameButton = Button:new(
    buttonBotPos,
    buttonSize,
    'Exit',
    nil,
    nil,
    function()
        love.event.quit()
    end
)

local nextLevelButton = Button:new(
    buttonTopPos,
    buttonSize,
    'Next level',
    nil,
    nil,
    function()
        GameGrid = LevelHandler:next()
        Menu.updateCellSize()
        Menu.current_state = MenuStateIndex.hidden
    end
)

local backToGameButton = Button:new(
    buttonTopPos,
    buttonSize,
    'Continue',
    nil,
    nil,
    function()
        Menu.current_state = MenuStateIndex.hidden
    end
)

-- Menu handler
---@class Menu
---@field states MenuState[]
---@field current_state MenuStateIndex
Menu = {
    states = {
        -- Main menu
        [MenuStateIndex.start] = MenuState:new({
            startButton, exitGameButton
        }),
        -- Pause menu
        [MenuStateIndex.pause] = MenuState:new({
            backToGameButton, exitToMenuButton
        }),
        -- Level selector
        [MenuStateIndex.levels] = MenuState:new({
        }),
        -- Level completed menu
        [MenuStateIndex.completed] = MenuState:new({
            nextLevelButton, exitToMenuButton
        }),
        -- Empty state 
        [MenuStateIndex.hidden] = MenuState:new()
    },
    current_state = MenuStateIndex.start
}

-- Draw current state
function Menu:draw()
    self.states[self.current_state]:draw()
end

-- Update current state
---@param dt number
---@param point Point
---@param pressed boolean
function Menu:update( dt, point, pressed )
    self.states[self.current_state]:update( dt, point, pressed )
end

function Menu.updateCellSize()
    local width, height = love.graphics.getDimensions()
    local gridX, gridY = GameGrid.size:coords();
    local isWidthBased = (width / height) / (gridX / gridY)
    Config.cellSize = math.floor(isWidthBased and height / gridY or width / gridX)
    love.graphics.setLineWidth( Config.cellSize * Config.lineWidth )
end