local utils = require "lib.utils.utils"

--- @alias CharacterState "idle"|"run"|"attack"|"hurt"

--- @class Logic
--- @field owner Character
--- @field mapLogic MapLogic
--- @field state CharacterState
local logic = {}
logic.__index = logic

--- @param id Id
--- @param position? Vec3
--- @param size? Vec3
local function new(id, position, size)
    return setmetatable({
        id = id,
        mapLogic = (require 'lib.character.map_logic').new(id, position, size),
        state = "idle"
    }, logic)
end

--- @param state CharacterState
function logic:setState(state)
    self.state = state
    self.owner.graphics.animation:setState(state, (state ~= "idle" and state ~= "run") and function()
        self:setState("idle")
    end or nil)
end

--- @param path Deque
function logic:followPath(path)
    if path:is_empty() then return end
    self:setState("run")
    self.mapLogic.path = path;
    ---@type Vec3
    local nextCell = path:peek_front()
    self:runTo(nextCell)
    path:pop_front()
end

--- @param target Vec3
function logic:runTo(target)
    self.mapLogic.t0 = love.timer.getTime()
    self.mapLogic.runTarget = target
    local charPos = self.mapLogic.position
    if target.x < charPos.x then
        self.owner.graphics.animation.side = LEFT
    elseif target.x > charPos.x then
        self.owner.graphics.animation.side = RIGHT
    end
end

function logic:update(dt)
    if self.state == "run" and self.mapLogic.runTarget then
        local delta = love.timer.getTime() - self.mapLogic.t0 or love.timer.getTime()
        local fraction = delta /
            (0.5 * self.mapLogic.runTarget:subtract(self.mapLogic.position):length()) -- бежим одну клетку за 500 мс, по диагонали больше
        if fraction >= 1 then                                                         -- анимация перемещена завершена
            self.mapLogic.position = self.mapLogic.runTarget
            if not self.mapLogic.path:is_empty() then                                 -- еще есть, куда бежать
                self:runTo(self.mapLogic.path:peek_front())
                self.mapLogic.path:pop_front()
            else -- мы добежали до финальной цели
                self:setState("idle")
                self.mapLogic.runTarget = nil
            end
        else                                                                                                        -- анимация перемещения не завершена
            self.mapLogic.displayedPosition = utils.lerp(self.mapLogic.position, self.mapLogic.runTarget, fraction) -- линейный интерполятор
        end
    end
end

return { new = new }