local Entity = require("entity")
local Animation = require("animation")

local Player = {}
Player.__index = Player
setmetatable(Player, { __index = Entity })

local MOVE_SPEED = 65
local SWIM_SPEED = 100
local JUMP_FORCE = -210
local GROUND_LAYER = "ground"

function Player.new(world, spawnX, spawnY)
  local w, h = 16, 16
  local pw, ph = 16, 16  -- physics body size
  local self = setmetatable(Entity:new(spawnX or 0, spawnY or 0, w, h, pw, ph), Player)

  self.spawnX = spawnX or 0
  self.spawnY = spawnY or 0
  self.pickups = {}

  self.directionState = { 'side', 'up', 'down', 'side_up', 'side_down' }
  self.directionIndex = 1
  self.direction = self.directionState[self.directionIndex]

  self.availableJumps = 0
  self:enablePhysics(world, "dynamic")

  self.fixture:setFriction(0)
  self.doubleJump = true
  self.jumpsUsed = 0
  self.animations = {
    idle = Animation.new("assets/player/idle.png", 16, 16, 0.6),
    running = Animation.new("assets/player/running.png", 16, 16, 0.4),
    going_up = Animation.new("assets/player/going_up.png", 16, 16, 0.8),
    going_down = Animation.new("assets/player/going_down.png", 16, 16, 0.5),
    stop_running = Animation.new("assets/player/stop_running.png", 16, 16, 0.5),
    ground_hit = Animation.new("assets/player/ground_hit.png", 16, 16, 0.5),
    swimming = Animation.new("assets/player/swimming.png", 16, 16, 0.5)
  }
  if love and love.filesystem and love.filesystem.getDirectoryItems then
    local ok, items = pcall(love.filesystem.getDirectoryItems, "assets/player")
    if ok and items then
      for _, filename in ipairs(items) do
        if filename:match("%.png$") then
          local name = filename:gsub("%.png$", "")
          if not self.animations[name] then
            self.animations[name] = Animation.new("assets/player/" .. filename, 16, 16, 0.3)
          end
        end
      end
    end
  end
  
  self.animations.ground_hit.looping = false
  self.animations.stop_running.looping = false

  self.currentAnim = self.animations.idle
  
  self.lastFacing = 1
  
  self.state = "idle"
  self.wasOnFloor = false
  
  self.vx = 0
  self.vy = 0
  
  self.grounded = false
  self.isInLiquid = false
  self.wasInLiquid = false
  self.waterSurfaceContact = false

  self.isDead = false
  self.respawnTimer = 0
  return self
end

function Player:trackDirectionByKeyPressed()
    local left  = love.keyboard.isDown("left", "a")
    local right = love.keyboard.isDown("right", "d")
    local up    = love.keyboard.isDown("up", "w")
    local down  = love.keyboard.isDown("down", "s")

    if up and left then
        self.directionIndex = 4 
    elseif up and right then
        self.directionIndex = 4
    elseif down and left then
        self.directionIndex = 5
    elseif down and right then
        self.directionIndex = 5

    elseif up then
        self.directionIndex = 2
    elseif down then
        self.directionIndex = 3
    elseif left then
        self.directionIndex = 1
    elseif right then
        self.directionIndex = 1
    end

    self.direction = self.directionState[self.directionIndex]
end

function Player:update(dt)
  self:syncFromPhysicsBody()

  if self.isDead then
    self.respawnTimer = self.respawnTimer - dt
    if self.respawnTimer <= 0 then
      self:respawn()
    end
    self.currentAnim = self.animations.dead or self.animations.idle
    self.currentAnim:update(dt)
    return
  end

  self:trackDirectionByKeyPressed()
  
  local vx, vy = self.body:getLinearVelocity()
  self.vx = vx
  self.vy = vy
  
  local c = self.contact or { floor = 0, wall = 0, ceiling = 0 }
  local onFloor = c.floor == 1
  local onWaterSurface = self.waterSurfaceContact
  local prevOnFloor = self.wasOnFloor
  local prevState = self.state

  local move = 0
  if love.keyboard.isDown("left", "a") then move = move - 1 end
  if love.keyboard.isDown("right", "d") then move = move + 1 end

  if self.isInLiquid then
    local vx, vy = self.body:getLinearVelocity()
    local mass = self.body:getMass()
    local gx, gy = self.body:getWorld():getGravity()

    if not self.wasInLiquid then
      vx = vx * 0.4
      vy = math.min(vy, 60)
      self.body:setLinearVelocity(vx, vy)
    end

    self.body:setLinearDamping(6)

    local buoyancy = 0.9
    self.body:applyForce(0, -gy * mass * buoyancy)

    local moveY = 0
    if love.keyboard.isDown("up", "w") then moveY = moveY - 1 end
    if love.keyboard.isDown("down", "s") then moveY = moveY + 1 end

    local inputLen = math.sqrt(move * move + moveY * moveY)
    if inputLen > 1 then
      move = move / inputLen
      moveY = moveY / inputLen
    end

    if move ~= 0 then self.lastFacing = move end
    self.body:applyForce(move * SWIM_SPEED, moveY * SWIM_SPEED)
  elseif onFloor or onWaterSurface then
    self.body:setLinearDamping(0)
    self.jumpsUsed = 0
    if move ~= 0 then
      self.lastFacing = move
      self.body:setLinearVelocity(move * MOVE_SPEED, vy)
    else
      self.body:setLinearVelocity(0, vy)
    end
  else
    self.body:setLinearDamping(0)
    if move ~= 0 then self.lastFacing = move end
    self.body:setLinearVelocity(move * MOVE_SPEED * 0.7, vy)
  end

  local desiredState
  if self.isInLiquid then
    desiredState = "swimming"
  elseif onFloor then
    desiredState = (move ~= 0) and "running" or "idle"
  else
    desiredState = (vy < 0) and "jumping" or "falling"
  end

  if self.isInLiquid then
    self.state = desiredState
  elseif self.state == "ground_hit" or self.state == "stop_running" then
    if not onFloor or self.currentAnim:isFinished() then
      self.state = desiredState
    end
  else
    local wasAirborne = prevState == "jumping" or prevState == "falling"
    if onFloor and not prevOnFloor and wasAirborne then
      self.state = "ground_hit"
      self.animations.ground_hit:reset()
    elseif onFloor and prevState == "running" and move == 0 then
      self.state = "stop_running"
      self.animations.stop_running:reset()
    else
      self.state = desiredState
    end
  end

  self.wasOnFloor = onFloor
  self.wasInLiquid = self.isInLiquid

  local animMap = {
    idle         = self.animations.idle,
    running      = self.animations.running,
    jumping      = self.animations.going_up,
    falling      = self.animations.going_down,
    swimming     = self.animations.swimming,
    stop_running = self.animations.stop_running,
    ground_hit   = self.animations.ground_hit,
    dead         = self.animations.dead or self.animations.idle,
  }
  self.currentAnim = animMap[self.state] or self.animations.idle
  self.currentAnim:update(dt)
end

function Player:die(nx, ny)
  if self.isDead then return end
  self.isDead = true
  self.state = "dead"
  self.respawnTimer = 4

  local len = math.sqrt(nx * nx + ny * ny)
  if len < 0.01 then
    nx, ny = 0, -1
  else
    nx, ny = nx / len, ny / len
  end

  local BOUNCE_SPEED = 200
  self.body:setLinearVelocity(nx * BOUNCE_SPEED, ny * BOUNCE_SPEED)
end

function Player:respawn()
  self.isDead = false
  self.respawnTimer = 0
  self.state = "idle"
  self.jumpsUsed = 0
  local cx = self.spawnX + self.physicsWidth / 2
  local cy = self.spawnY + self.height - self.physicsHeight / 2
  self.body:setPosition(cx, cy)
  self.body:setLinearVelocity(0, 0)
  self:syncFromPhysicsBody()
end

function Player:jump()
  if self.isDead then return false end
  local c = self.contact or { floor = 0, wall = 0, ceiling = 0 }
  local onFloor = c.floor == 1
  local onWall = c.wall == 1
  local onWaterSurface = self.waterSurfaceContact

  if onWall and not onFloor then
    return false
  end

  local maxJumps = self.doubleJump and 1 or 0

  if self.jumpsUsed >= maxJumps then
    return false
  end

  if self.isInLiquid and not onWaterSurface then
    return false
  end

  self.body:setLinearVelocity(self.body:getLinearVelocity(), JUMP_FORCE)

  self.state = "jumping"
  self.animations.going_up:reset()

  self.jumpsUsed = self.jumpsUsed + 1

  return true
end

function Player:draw()
  local flip = (self.lastFacing < 0)
  self.currentAnim:draw(self.x, self.y, flip)
end

function Player:getBody()
  return self.body
end

return Player