-- Gold's intro menu (engine/menus/main_menu.asm MainMenu).
--
-- Which entries appear depends on whether a save exists
-- (MainMenu_GetWhichMenu reads wSaveFileExists):
--   no save  -> NEW GAME, OPTION
--   save     -> CONTINUE, NEW GAME, OPTION
-- MYSTERY GIFT is a third case on a CGB with an unlocked SRAM counter; it
-- needs the link cable, so it is not offered here.
--
-- With a save present the menu also shows the clock box
-- (MainMenu_PrintCurrentTimeAndDay): a 4x13 textbox at (0,12) with the day of
-- the week and the current time.  Its .PlaceTime calls UpdateTime before it
-- reads hHours, so it prints the GAME clock -- the RTC through the save's own
-- wStartHour / wStartMinute base -- and not the raw RTC.  That is the same
-- read the overworld makes (World:hour), so the time on this screen and the
-- light outside the door always agree.
--
-- Choosing CONTINUE shows the save panel (DisplaySaveInfoOnContinue) and waits
-- for A to confirm or B to back out (ConfirmContinue).

local Chrome = require("src.ui.gen2.Chrome")
local Clock = require("src.core.gen2.Clock")
local Logger = require("src.core.Logger")
local Music = require("src.core.Music")
local Runtime = require("src.mods.Runtime")
local Save = require("src.core.gen2.Save")
local Strings = require("src.core.Strings")

local MainMenu = {}
MainMenu.__index = MainMenu
MainMenu.isOpaque = true

-- MainMenu_PrintCurrentTimeAndDay's PrintDayOfWeek strings.  Clock.DAY_NAMES
-- / Clock.weekdayName is the single translated home for this table (see
-- InitClock.lua's DAYS), so this screen's clock box cannot drift from the
-- Pokegear's own.
local DAYS = Clock.DAY_NAMES

-- MUSIC_MAIN_MENU; resolved by name so a cache without it just stays quiet.
local MENU_MUSIC = "Music_MainMenu"

function MainMenu:wantsFillScale() return true end
function MainMenu:drawsWidescreen() return true end

-- opts: onNewGame(), onContinue(save), onOption(), hasSave (override for
-- tests), save (a pre-loaded save table, so the menu does not read the disk
-- twice), clock ({ hour, minute, weekday }) to pin the clock box.
function MainMenu.new(game, opts)
  opts = opts or {}
  local self = setmetatable({}, MainMenu)
  self.game = game
  self.onNewGame = opts.onNewGame
  self.onContinue = opts.onContinue
  self.onOption = opts.onOption
  self.onExit = opts.onExit
  self.clock = opts.clock

  self.save = opts.save
  if self.save == nil and opts.hasSave ~= false then
    local loaded = Save.load()
    self.save = loaded
  end
  self.hasSave = opts.hasSave
  if self.hasSave == nil then self.hasSave = self.save ~= nil end

  self.phase = "menu" -- menu | confirm
  self:buildList()
  return self
end

-- ui.title_menu.items identity: an unhooked build hands its own list back.
local function sameItems(_, items) return items end

function MainMenu:buildList()
  local items = {}
  if self.hasSave then
    items[#items + 1] = { label = Strings("CONTINUE"), value = "continue" }
  end
  items[#items + 1] = { label = Strings("NEW GAME"), value = "new" }
  items[#items + 1] = { label = Strings("OPTION"), value = "option" }
  -- Not on the cart: a cartridge is left by switching the console off, and
  -- there is no console here.  Mirrors the Gen 1 port's title menu
  -- (src/ui/TitleState.lua), which adds the same row for the same reason.
  items[#items + 1] = { label = Strings("EXIT GAME"), value = "exit" }
  -- The same hook name and the same (game, items) payload the Gen 1 title
  -- menu raises (src/ui/TitleState.lua:openMenu), so one mod's title rows
  -- serve both games; only the row shape differs, because Chrome.List reads
  -- { label, value } where the Gen 1 Menu reads { label, onSelect }.  A hook
  -- that answers with anything but a table is degraded to the vanilla list
  -- rather than leaving the player with no way into the game.
  local hooked = Runtime.call("ui.title_menu.items", sameItems, self.game, items)
  if type(hooked) == "table" then
    items = hooked
  else
    Logger.error("ui.title_menu.items returned %s; keeping the vanilla items",
                 type(hooked))
  end
  -- MenuHeader's "db 1 ; default option": the first entry, so CONTINUE when
  -- there is a save and NEW GAME when there is not.
  self.list = Chrome.List.new({
    items = items,
    x = 2, y = 2, spacing = 2,
    wrap = true,
    index = 1,
    onChoose = function(value) self:choose(value) end,
  })
end

function MainMenu:choose(value)
  if value == "continue" then
    self.phase = "confirm"
    self.confirmDelay = 20 -- ld c, 20 / DelayFrames before input is read
  elseif value == "new" then
    if self.onNewGame then self.onNewGame() end
  elseif value == "option" then
    if self.onOption then self.onOption() end
  elseif value == "exit" then
    if self.onExit then
      self.onExit()
    elseif love.event and love.event.quit then
      love.event.quit()
    end
  end
end

function MainMenu:enter()
  local data = self.game and self.game.data
  local audio = data and data.audio
  if audio and audio.runtime and audio.songs and audio.songs[MENU_MUSIC] then
    Music.play(data, MENU_MUSIC)
  end
end

function MainMenu:update(_dt)
  local input = self.game and self.game.input
  if not input then return end
  if self.phase == "confirm" then
    if self.confirmDelay and self.confirmDelay > 0 then
      self.confirmDelay = self.confirmDelay - 1
      return
    end
    if input:wasPressed("a") then
      if self.onContinue then self.onContinue(self.save) end
    elseif input:wasPressed("b") then
      self.phase = "menu"
    end
    return
  end
  self.list:update(input)
end

-- .PlaceTime's three reads: GetWeekday, hHours and hMinutes, all of them after
-- UpdateTime.  `weekday` is returned 1-based for the DAYS table above, which is
-- os.date's wday numbering and NOT wCurDay's (Clock.weekday counts SUNDAY 0).
-- opts.clock still pins the box outright for a driver's screenshots.
function MainMenu:clockParts()
  if self.clock then
    return self.clock.hour or 0, self.clock.minute or 0,
      self.clock.weekday or 1
  end
  local save = self.save
  return Clock.hour(save), Clock.minute(save), Clock.weekday(save) + 1
end

function MainMenu:drawClockBox()
  -- Textbox at (0,12) with 4 interior rows and 13 interior columns.
  Chrome.textbox(0, 12, 13, 4)
  local hour, minute, weekday = self:clockParts()
  Chrome.print(Clock.weekdayName(weekday) or "DAY", 1, 14)
  -- PrintHour prints 1-12 with no leading zero, then ':' then two zero-padded
  -- minutes; the AM/PM half is drawn by PrintHour itself.
  local display = hour % 12
  if display == 0 then display = 12 end
  local half = Strings(hour < 12 and "AM" or "PM")
  Chrome.print(("%s:%s %s"):format(
    Chrome.number(display, 2), Chrome.number(minute, 2, true), half), 4, 16)
end

function MainMenu:drawSavePanel()
  local summary = Save.summary(self.save)
  -- DisplaySaveInfoOnContinue: a box down the right side listing the trainer.
  Chrome.textbox(4, 0, 14, 9)
  if not summary then
    Chrome.print(Strings("NO SAVE FILE"), 5, 2)
    return
  end
  Chrome.print(Strings("PLAYER %s", summary.name), 5, 2)
  Chrome.print(Strings("BADGES"), 5, 4)
  Chrome.printRight(tostring(summary.badges), 17, 4)
  Chrome.print(Strings("POKéDEX"), 5, 6)
  Chrome.printRight(tostring(summary.caught), 17, 6)
  Chrome.print(Strings("TIME"), 5, 8)
  Chrome.printRight(("%d:%s"):format(
    summary.hours, Chrome.number(summary.minutes, 2, true)), 17, 8)
end

function MainMenu:drawPanel()
  Chrome.clear()
  if self.phase == "confirm" then
    self:drawSavePanel()
    return
  end
  -- MenuHeader: menu_coords 0, 0, 14, 7 -- a box from (0,0) to (14,7), which
  -- is exactly two rows per entry plus the border.  The extra EXIT GAME row
  -- grows it the way AutomaticGetMenuBottomCoord would.
  Chrome.box(0, 0, 15,
    math.min(#self.list.items * 2 + 2, Chrome.SCREEN_H))
  self.list:draw()
  if self.hasSave then self:drawClockBox() end
end

function MainMenu:draw()
  self:drawPanel()
end

function MainMenu:drawWidescreen(winW, winH)
  local G = love.graphics
  G.setColor(1, 1, 1, 1)
  G.rectangle("fill", 0, 0, winW, winH)
  local scale = Chrome.fitScale(winW, winH)
  G.push()
  G.translate(Chrome.fitOrigin(winW, winH, scale))
  G.scale(scale, scale)
  self:drawPanel()
  G.pop()
end

MainMenu.DAYS = DAYS

return MainMenu