-- title:   Mr Anderson's Adventure
-- author:  Zsolt Tasnadi
-- desc:    Life of a programmer in the Vector
-- site:    http://teletype.hu
-- license: MIT License
-- version: 0.6
-- script:  lua

--------------------------------------------------------------------------------
-- Game Configuration
--------------------------------------------------------------------------------
local Config = {
  screen = {
    width = 240,
    height = 136
  },
  colors = {
    black = 0,
    light_grey = 13,
    dark_grey = 14,
    green = 6,
    npc = 8,
    item = 12 -- yellow
  },
  player = {
    w = 8,
    h = 8,
    start_x = 120,
    start_y = 128,
    sprite_id = 1
  },
  physics = {
    gravity = 0.5,
    jump_power = -5,
    move_speed = 1.5,
    max_jumps = 2,
  },
  timing = {
    splash_duration = 120 -- 2 seconds at 60fps
  }
}

--------------------------------------------------------------------------------
-- Game States
--------------------------------------------------------------------------------
local GAME_STATE_SPLASH = 0
local GAME_STATE_INTRO = 1
local GAME_STATE_MENU = 2
local GAME_STATE_GAME = 3
local GAME_STATE_DIALOG = 4

--------------------------------------------------------------------------------
-- Modules
--------------------------------------------------------------------------------
local Splash = {}
local Intro = {}
local Menu = {}
local Game = {}
local UI = {}
local Input = {}
local NpcActions = {}
local ItemActions = {}
local MenuActions = {}

--------------------------------------------------------------------------------
-- Game State
--------------------------------------------------------------------------------
local State = {
  game_state = GAME_STATE_SPLASH,
  intro = {
    y = Config.screen.height,
    speed = 0.5,
    text = "Mr. Anderson is an average\nprogrammer. His daily life\nrevolves around debugging,\npull requests, and end-of-sprint\nmeetings, all while secretly\ndreaming of being destined\nfor something more."
  },
  current_screen = 1,
  dialog_text = "",
  splash_timer = Config.timing.splash_duration,
  player = {
    x = Config.player.start_x,
    y = Config.player.start_y,
    w = Config.player.w,
    h = Config.player.h,
    vx = 0,
    vy = 0,
    jumps = 0,
    sprite_id = Config.player.sprite_id
  },
  ground = {
    x = 0,
    y = Config.screen.height,
    w = Config.screen.width,
    h = 8
  },
  menu_items = {},
  selected_menu_item = 1,
  dialog_menu_items = {},
  selected_dialog_menu_item = 1,
  active_entity = nil,
  -- Screen data
  screens = {
    { -- Screen 1
      name = "Screen 1",
      platforms = {
        {x = 80, y = 110, w = 40, h = 8},
        {x = 160, y = 90, w = 40, h = 8}
      },
      npcs = {
        {x = 180, y = 82, name = "Trinity", sprite_id = 2},
        {x = 90, y = 102, name = "Oracle", sprite_id = 3}
      },
      items = {
        {x = 100, y = 128, w=8, h=8, name = "Key", sprite_id = 4}
      }
    },
    { -- Screen 2
      name = "Screen 2",
      platforms = {
        {x = 30, y = 100, w = 50, h = 8},
        {x = 100, y = 80, w = 50, h = 8},
        {x = 170, y = 60, w = 50, h = 8}
      },
      npcs = {
        {x = 120, y = 72, name = "Morpheus", sprite_id = 5},
        {x = 40, y = 92, name = "Tank", sprite_id = 6}
      },
      items = {
        {x = 180, y = 52, w=8, h=8, name = "Potion", sprite_id = 7}
      }
    },
    { -- Screen 3
      name = "Screen 3",
      platforms = {
        {x = 50, y = 110, w = 30, h = 8},
        {x = 100, y = 90, w = 30, h = 8},
        {x = 150, y = 70, w = 30, h = 8},
        {x = 200, y = 50, w = 30, h = 8}
      },
      npcs = {
        {x = 210, y = 42, name = "Agent Smith", sprite_id = 8},
        {x = 160, y = 62, name = "Cypher", sprite_id = 9}
      },
      items = {}
    }
  }
}

--------------------------------------------------------------------------------
-- Menu Actions
--------------------------------------------------------------------------------
function MenuActions.play()
  -- Reset player state and screen for a new game
  State.player.x = Config.player.start_x
  State.player.y = Config.player.start_y
  State.player.vx = 0
  State.player.vy = 0
  State.player.jumps = 0
  State.current_screen = 1
  State.game_state = GAME_STATE_GAME
end

function MenuActions.exit()
  exit()
end

-- Initialize menu items after actions are defined
State.menu_items = {
  {label = "Play", action = MenuActions.play},
  {label = "Exit", action = MenuActions.exit}
}

--------------------------------------------------------------------------------
-- NPC Actions
--------------------------------------------------------------------------------
function NpcActions.talk_to() end
function NpcActions.fight() end
function NpcActions.goodbye()
  State.game_state = GAME_STATE_GAME
end

--------------------------------------------------------------------------------
-- Item Actions
--------------------------------------------------------------------------------
function ItemActions.use() end
function ItemActions.look_at() end
function ItemActions.take_away() end
function ItemActions.goodbye()
  State.game_state = GAME_STATE_GAME
end


--------------------------------------------------------------------------------
-- Input Module
--------------------------------------------------------------------------------
function Input.up() return btnp(0) end
function Input.down() return btnp(1) end
function Input.left() return btn(2) end
function Input.right() return btn(3) end
function Input.jump() return btnp(4) end
function Input.action() return btnp(4) end
function Input.interact() return btnp(5) end -- B button
function Input.back() return btnp(5) end

--------------------------------------------------------------------------------
-- UI Module
--------------------------------------------------------------------------------
function UI.draw_top_bar(title)
  rect(0, 0, Config.screen.width, 10, Config.colors.dark_grey)
  print(title, 3, 2, Config.colors.green)
end

function UI.draw_dialog()
  rect(40, 40, 160, 80, Config.colors.black)
  rectb(40, 40, 160, 80, Config.colors.green)
  print(State.dialog_text, 120 - #State.dialog_text * 2, 45, Config.colors.light_grey)
  UI.draw_menu(State.dialog_menu_items, State.selected_dialog_menu_item, 50, 60)
end

function UI.draw_menu(items, selected_item, x, y)
  for i, item in ipairs(items) do
    local current_y = y + (i-1)*10
    if i == selected_item then
      print(">", x - 8, current_y, Config.colors.green)
    end
    print(item.label, x, current_y, Config.colors.green)
  end
end

function UI.update_menu(items, selected_item)
  if Input.up() then
    selected_item = selected_item - 1
    if selected_item < 1 then
      selected_item = #items
    end
  elseif Input.down() then
    selected_item = selected_item + 1
    if selected_item > #items then
      selected_item = 1
    end
  end
  return selected_item
end

--------------------------------------------------------------------------------
-- Splash Module
--------------------------------------------------------------------------------
function Splash.draw()
  cls(Config.colors.dark_grey)
  print("Mr. Anderson's", 78, 60, Config.colors.green)
  print("Addventure", 90, 70, Config.colors.green)
end

function Splash.update()
  State.splash_timer = State.splash_timer - 1
  if State.splash_timer <= 0 or Input.action() then
    State.game_state = GAME_STATE_INTRO
  end
end

--------------------------------------------------------------------------------
-- Intro Module
--------------------------------------------------------------------------------
function Intro.draw()
  cls(Config.colors.dark_grey)
  local x = (Config.screen.width - 132) / 2 -- Centered text
  print(State.intro.text, x, State.intro.y, Config.colors.green)
end

function Intro.update()
  State.intro.y = State.intro.y - State.intro.speed

  -- Count lines in intro text to determine when scrolling is done
  local lines = 1
  for _ in string.gmatch(State.intro.text, "\n") do
    lines = lines + 1
  end

  -- When text is off-screen, go to menu
  if State.intro.y < -lines * 8 then
    State.game_state = GAME_STATE_MENU
  end

  -- Skip intro by pressing A
  if Input.action() then
    State.game_state = GAME_STATE_MENU
  end
end

--------------------------------------------------------------------------------
-- Menu Module
--------------------------------------------------------------------------------
function Menu.draw()
  cls(Config.colors.dark_grey)
  UI.draw_top_bar("Main Menu")
  UI.draw_menu(State.menu_items, State.selected_menu_item, 108, 70)
end

function Menu.update()
  State.selected_menu_item = UI.update_menu(State.menu_items, State.selected_menu_item)

  if Input.action() then
    local selected_item = State.menu_items[State.selected_menu_item]
    if selected_item and selected_item.action then
      selected_item.action()
    end
  end
end

--------------------------------------------------------------------------------
-- Game Module
--------------------------------------------------------------------------------
function Game.draw()
  local currentScreenData = State.screens[State.current_screen]
  
  cls(Config.colors.dark_grey)
  UI.draw_top_bar(currentScreenData.name)

  -- Draw platforms
  for _, p in ipairs(currentScreenData.platforms) do
    rect(p.x, p.y, p.w, p.h, Config.colors.green)
  end

  -- Draw items
  for _, item in ipairs(currentScreenData.items) do
    spr(item.sprite_id, item.x, item.y, 0)
  end
  
  -- Draw NPCs
  for _, npc in ipairs(currentScreenData.npcs) do
    spr(npc.sprite_id, npc.x, npc.y, 0)
  end

  -- Draw ground
  rect(State.ground.x, State.ground.y, State.ground.w, State.ground.h, Config.colors.dark_grey)

  -- Draw player
  spr(State.player.sprite_id, State.player.x, State.player.y, 0)
end

function Game.update()
  -- Handle input
  if Input.left() then
    State.player.vx = -Config.physics.move_speed
  elseif Input.right() then
    State.player.vx = Config.physics.move_speed
  else
    State.player.vx = 0
  end

  if Input.jump() and State.player.jumps < Config.physics.max_jumps then
    State.player.vy = Config.physics.jump_power
    State.player.jumps = State.player.jumps + 1
  end

  -- Update player position
  State.player.x = State.player.x + State.player.vx
  State.player.y = State.player.y + State.player.vy

  -- Screen transition
  if State.player.x > Config.screen.width - State.player.w then
    if State.current_screen < #State.screens then
      State.current_screen = State.current_screen + 1
      State.player.x = 0
    else
      State.player.x = Config.screen.width - State.player.w
    end
  elseif State.player.x < 0 then
    if State.current_screen > 1 then
      State.current_screen = State.current_screen - 1
      State.player.x = Config.screen.width - State.player.w
    else
      State.player.x = 0
    end
  end

  -- Apply gravity
  State.player.vy = State.player.vy + Config.physics.gravity

  local currentScreenData = State.screens[State.current_screen]
  -- Collision detection with platforms
  for _, p in ipairs(currentScreenData.platforms) do
    if State.player.vy > 0 and State.player.y + State.player.h >= p.y and State.player.y + State.player.h <= p.y + p.h and State.player.x + State.player.w > p.x and State.player.x < p.x + p.w then
      State.player.y = p.y - State.player.h
      State.player.vy = 0
      State.player.jumps = 0
    end
  end

  -- Collision detection with ground
  if State.player.y + State.player.h > State.ground.y then
    State.player.y = State.ground.y - State.player.h
    State.player.vy = 0
    State.player.jumps = 0
  end

  -- Entity interaction
  if Input.interact() then
    local interaction_found = false
    -- NPC interaction
    for _, npc in ipairs(currentScreenData.npcs) do
      if math.abs(State.player.x - npc.x) < 12 and math.abs(State.player.y - npc.y) < 12 then
        State.active_entity = npc
        State.dialog_text = npc.name
        State.game_state = GAME_STATE_DIALOG
        State.dialog_menu_items = {
          {label = "Talk to", action = NpcActions.talk_to},
          {label = "Fight", action = NpcActions.fight},
          {label = "Goodbye", action = NpcActions.goodbye}
        }
        State.selected_dialog_menu_item = 1
        interaction_found = true
        break
      end
    end

    if interaction_found then return end

    -- Item interaction
    for _, item in ipairs(currentScreenData.items) do
      if math.abs(State.player.x - item.x) < 8 and math.abs(State.player.y - item.y) < 8 then
        State.active_entity = item
        State.dialog_text = item.name
        State.game_state = GAME_STATE_DIALOG
        State.dialog_menu_items = {
          {label = "Use", action = ItemActions.use},
          {label = "Look at", action = ItemActions.look_at},
          {label = "Take away", action = ItemActions.take_away},
          {label = "Goodbye", action = ItemActions.goodbye}
        }
        State.selected_dialog_menu_item = 1
        break
      end
    end
  end
end

function Game.update_dialog()
  State.selected_dialog_menu_item = UI.update_menu(State.dialog_menu_items, State.selected_dialog_menu_item)

  if Input.action() then
    local selected_item = State.dialog_menu_items[State.selected_dialog_menu_item]
    if selected_item and selected_item.action then
      selected_item.action()
    end
  end
  
  if Input.back() then
    State.game_state = GAME_STATE_GAME
  end
end

--------------------------------------------------------------------------------
-- Main Game Loop
--------------------------------------------------------------------------------
local STATE_HANDLERS = {
  [GAME_STATE_SPLASH] = function()
    Splash.update()
    Splash.draw()
  end,
  [GAME_STATE_INTRO] = function()
    Intro.update()
    Intro.draw()
  end,
  [GAME_STATE_MENU] = function()
    Menu.update()
    Menu.draw()
  end,
  [GAME_STATE_GAME] = function()
    Game.update()
    Game.draw()
  end,
  [GAME_STATE_DIALOG] = function()
    Game.draw() -- Draw game behind dialog
    UI.draw_dialog()
    Game.update_dialog()
  end,
}

function TIC()
  local handler = STATE_HANDLERS[State.game_state]
  if handler then
    handler()
  end
end


-- <TILES>
-- 000:4444444444444444444444444444444444444444444444444444444444444444
-- 001:1111111111111111111111111111111111111111111111111111111111111111
-- 002:5555555555555555555555555555555555555555555555555555555555555555
-- 003:6666666666666666666666666666666666666666666666666666666666666666
-- 004:7777777777777777777777777777777777777777777777777777777777777777
-- 005:8888888888888888888888888888888888888888888888888888888888888888
-- 006:9999999999999999999999999999999999999999999999999999999999999999
-- 007:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
-- 008:bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
-- </TILES>

-- <WAVES>
-- 000:00000000ffffffff00000000ffffffff
-- 001:0123456789abcdeffedcba9876543210
-- 002:0123456789abcdef0123456789abcdef
-- </WAVES>

-- <SFX>
-- 000:000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000304000000000
-- </SFX>

-- <TRACKS>
-- 000:100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
-- </TRACKS>

-- <PALETTE>
-- 000:1a1c2c5d275db13e53ef7d57ffcd75a7f07038b76425717929366f3b5dc941a6f673eff7f4f4f494b0c2566c86333c57
-- </PALETTE>