require 'lib.utils.vec3'


--- @alias Id integer
--- @type Id
local characterId = 1

--- @class Character
--- @field id Id
--- @field behaviors Behavior[]
--- @field _behaviorsIdx {string: integer}
local character = {}
character.__index = character

--- Создаёт персонажа, которым будет управлять или игрок или компьютер
--- @param name string
--- @param template ClassTemplate
--- @param spriteDir table
--- @param position? Vec3
--- @param size? Vec3
--- @param level? integer
local function spawn(name, template, spriteDir, position, size, level)
    local char = {}

    char = setmetatable(char, character)
    char.id = characterId
    characterId = characterId + 1
    char.behaviors = {}
    char._behaviorsIdx = {}

    char:addBehavior {
        Tree.behaviors.map.new(position, size),
        Tree.behaviors.animated.new(spriteDir),
        Tree.behaviors.spellcaster.new()
    }

    Tree.level.characters[char.id] = char
    return char
end

--- Проверяет, есть ли у персонажа поведение [behavior].
--- @generic T : Behavior
--- @param behavior T
--- @return T | nil
function character:has(behavior)
    --- @cast behavior Behavior
    local idx = self._behaviorsIdx[behavior.id]
    if not idx then return nil end
    return self.behaviors[idx] or nil
end

--- Если у персонажа есть поведение [behavior], применяет к нему [fn]
---
--- Дальше meme для интеллектуалов
---
--- *Я: мам купи мне >>=*
---
--- *Мама: у нас дома есть >>=*
---
--- *Дома:*
--- @generic T : Behavior
--- @generic V
--- @param behavior T
--- @param fn fun(behavior: T) : V | nil
--- @return V | nil
function character:try(behavior, fn)
    local b = self:has(behavior)
    if not b then return end
    return fn(b)
end

--- usage:
--- addBehavior( {logic.new(), graphics.new(), ...} )
---
--- or you may chain this if you are a wannabe haskell kiddo
--- @param behaviors Behavior[]
--- @return Character | nil
function character:addBehavior(behaviors)
    for _, b in ipairs(behaviors) do
        if b.dependencies then
            for _, dep in ipairs(b.dependencies) do
                if not self:has(dep) then
                    return print("[Character]: cannot add \"" .. b.id ..
                        "\" for a character (Id = " .. self.id .. "): needs \"" .. dep.id .. "\"!")
                end
            end
        end
        b.owner = self
        table.insert(self.behaviors, b)
        self._behaviorsIdx[b.id] = #self.behaviors
    end
    return self
end

function character:update(dt)
    for _, b in ipairs(self.behaviors) do
        if b.update then b:update(dt) end
    end
end

function character:draw()
    for _, b in ipairs(self.behaviors) do
        if b.draw then b:draw() end
    end
end

return { spawn = spawn }