-- STADIUM battles: importing the ROM, instead of being told where to put it.
--
-- The mod ships no Pokemon Stadium models and cannot -- they are that game's
-- data -- so the player supplies the cartridge. The original instruction for
-- that was "make a folder called baseroms next to the game and drop the file
-- in it", which is a fine sentence to write and a poor thing to ask. It needs
-- a folder the player has to create, in a place that is different on every
-- platform and is inside an unwritable archive on a packaged build, and it
-- fails SILENTLY: the two STADIUM rungs are simply not on the row, and
-- nothing on screen says why.
--
-- So this opens a file picker instead, from a row on the OPTIONS menu, and
-- the folder keeps working for anyone who prefers it (StadiumInstall).
--
-- ------- the picker is the host's, not LOVE's
--
-- LOVE 11.5 has no file dialog. love.window.showFileDialog arrived in 12 and
-- love.system.pickFile is a native bridge this project ships for mobile
-- rather than part of LOVE at all. What every desktop OS does have is a
-- dialog reachable from a shell, so that is what is used here -- osascript on
-- macOS, PowerShell's OpenFileDialog on Windows, zenity then kdialog on
-- Linux.
--
-- This is deliberately the SAME four commands the engine's own ROM importer
-- uses for the Game Boy cartridge (src/import/RomImporter.lua's chooseRom),
-- down to writing the Windows pick as UTF-8 -- the console's OEM codepage
-- mangles a non-ASCII path into something that crashes the next text draw.
-- Being a second copy of that is worth it: a mod cannot call into the
-- importer's private helpers, and the alternative is asking the engine to
-- grow a seam for one caller.
--
-- The dialog BLOCKS. io.popen waits for the player to choose, and the game is
-- frozen for as long as it is up. That is what the engine's importer does
-- too, it is what a modal dialog means, and the frame it freezes on is an
-- options menu.
--
-- ------- and the ROM is not kept
--
-- The picked file is read, built from, and forgotten -- nothing is copied
-- anywhere. A Stadium cartridge is 32 MB and the models built out of it are
-- 34, so keeping both would double the cost of a feature for a file that has
-- no further use: the packs are what the game reads afterwards, and the
-- marker records the ROM's md5 so a swapped cartridge is still noticed.
--
-- The one thing that costs is a format bump, which invalidates the packs and
-- leaves nothing to rebuild from. That is what the row still being there is
-- for -- it reads READY, and pressing it imports again.

-- the mod namespace (see main.lua): V.require loads a sibling module
local V = ...

local StadiumInstall = V.require("StadiumInstall")

local StadiumRomPick = {}

StadiumRomPick.LABEL = "STADIUM ROM"
StadiumRomPick.ID = "DRAMATIC_SHAPE:stadiumRom"

-- Names the REVISION, because that is the thing a player gets wrong: the
-- model offsets are keyed to US 1.0 and nothing else is going to work.
local PROMPT = "Choose your Pokemon Stadium (US) 1.0 ROM"

-- ------- the host, at arm's length
--
-- Everything below is read through pcall and a presence test. The mod loader
-- hands a mod the real `io` and `os` today, but a mod that TAKES that for
-- granted is one that stops loading the day a sandbox arrives -- and this is
-- a convenience on top of a folder scan that works without any of it.

local function haveShell()
  local ok, popen = pcall(function() return io and io.popen end)
  return (ok and popen) and true or false
end

local function haveFiles()
  local ok, open = pcall(function() return io and io.open end)
  return (ok and open) and true or false
end

local function osName()
  local ok, name = pcall(function() return love.system.getOS() end)
  return ok and name or nil
end

-- Run a command and return its trimmed stdout, or nil for anything that did
-- not produce a line -- a cancelled dialog, a missing zenity, a shell that
-- is not there.
local function commandOutput(cmd)
  if not haveShell() then return nil end
  local ok, pipe = pcall(io.popen, cmd)
  if not (ok and pipe) then return nil end
  local okRead, out = pcall(pipe.read, pipe, "*a")
  pcall(pipe.close, pipe)
  if not (okRead and type(out) == "string") then return nil end
  out = out:gsub("^%s+", ""):gsub("%s+$", "")
  return (out ~= "") and out or nil
end

-- ------- can this machine open one at all
--
-- Desktop only, and honestly so. On ANDROID the picker is a native bridge
-- (love.system.pickFile) whose kind -> filename mapping is a fixed list of
-- three in the engine's own C++, and an unrecognised kind falls through to
-- `picked_rom.gb` -- which is the file the engine's Game Boy importer is
-- watching. Calling it for a 32 MB N64 ROM would hand that to the wrong
-- importer, so it is not called.
--
-- Android does not need it as badly, either: conf.lua points the save
-- directory at the app's external-files folder, so `baseroms/` there is
-- reachable over USB or any file manager with no root and no permission
-- prompt, which is the flow the engine's own comment describes for
-- picker-less builds.
function StadiumRomPick.available()
  if not (haveShell() and haveFiles()) then return false end
  local p = osName()
  return p == "Windows" or p == "OS X" or p == "Linux"
end

-- Open the dialog. Returns the chosen absolute path, or nil when the player
-- cancelled or no dialog could be opened.
function StadiumRomPick.choose()
  local p = osName()
  if p == "OS X" then
    return commandOutput(
      ([[osascript -e 'POSIX path of (choose file with prompt "%s" of type ]]
       .. [[{"z64", "n64", "v64"})' 2>/dev/null]]):format(PROMPT))
  elseif p == "Windows" then
    local script = table.concat({
      "Add-Type -AssemblyName System.Windows.Forms;",
      "$d=New-Object System.Windows.Forms.OpenFileDialog;",
      "$d.Title='" .. PROMPT .. "';",
      "$d.Filter='Nintendo 64 ROM (*.z64;*.n64;*.v64)|*.z64;*.n64;*.v64"
      .. "|All files (*.*)|*.*';",
      -- as UTF-8: the console's OEM codepage would mangle a non-ASCII path
      -- and crash the next text draw that showed it
      "if($d.ShowDialog() -eq 'OK'){[Console]::OutputEncoding="
      .. "[Text.Encoding]::UTF8; [Console]::Write($d.FileName)}",
    })
    return commandOutput(
      'powershell -NoProfile -STA -Command "' .. script .. '"')
  elseif p == "Linux" then
    local path = commandOutput(
      ([[zenity --file-selection --title="%s" ]]
       .. [[--file-filter="Nintendo 64 ROM | *.z64 *.n64 *.v64" 2>/dev/null]])
        :format(PROMPT))
    if path then return path end
    -- zenity is absent on plenty of installs (and on most handheld Linux
    -- distributions); KDE's own dialog is the usual second answer
    return commandOutput(
      [[kdialog --getopenfilename "$HOME" "*.z64 *.n64 *.v64|]]
      .. [[Nintendo 64 ROM" 2>/dev/null]])
  end
  return nil
end

-- Read an ABSOLUTE path, which love.filesystem cannot: it only sees inside
-- the physfs mount, and a picked file is anywhere on the disk. Returns the
-- bytes, or nil plus a reason short enough to fit the loading screen.
function StadiumRomPick.read(path)
  if not haveFiles() then return nil, "no file access" end
  local ok, fp = pcall(io.open, path, "rb")
  if not (ok and fp) then return nil, "could not open that file" end
  local okRead, bytes = pcall(fp.read, fp, "*a")
  pcall(fp.close, fp)
  if not (okRead and type(bytes) == "string" and #bytes > 0) then
    return nil, "could not read that file"
  end
  return bytes
end

-- ------- the whole flow, from one keypress
--
-- Pick, read, start the build, and put the loading screen up over whatever
-- asked -- which is the OPTIONS menu, so the row is there again underneath
-- when the build finishes and now reads READY.
--
-- A CANCELLED dialog is not a failure and says nothing: the player opened a
-- file browser and changed their mind, and a mod that made an announcement
-- about that would be the second most annoying thing on the menu.
--
-- Everything else lands on the loading screen's own failure state, because it
-- is the one surface in this mode with room for a sentence -- and because a
-- player who has just chosen the wrong file is owed a reason and not a row
-- that quietly goes on saying IMPORT.
function StadiumRomPick.import(game)
  if StadiumInstall.status.state == "building" then return false end
  local path = StadiumRomPick.choose()
  if not path then return false end

  local StadiumScreen = V.require("StadiumScreen")
  local function fail(why)
    StadiumInstall.status.state = "failed"
    StadiumInstall.status.error = why
    if game and game.stack then
      game.stack:push(StadiumScreen.new(game, true))
    end
    return false
  end

  local bytes, err = StadiumRomPick.read(path)
  if not bytes then return fail(err or "could not read that file") end

  local ok, beginErr = StadiumInstall.beginFrom(bytes, path)
  if not ok then return fail(tostring(beginErr)) end
  if game and game.stack then
    game.stack:push(StadiumScreen.new(game, true))
  end
  return true
end

-- ------- the row
--
-- An ACTION rather than a value, which is why it is not a ModSetting: there
-- is no rung to store, nothing for the mod manager's page to persist, and
-- nothing to restore on the next boot. What it shows is a STATE -- the models
-- are there or they are not -- and what it does is the only thing it can do.
--
-- Still offered once they ARE there, reading READY. Pressing it imports
-- again, which is how a player swaps to a different revision, and how they
-- rebuild after a format bump has invalidated the packs and left nothing on
-- disk to rebuild from (see the header: the ROM is not kept).
--
-- nil where no dialog can be opened, which takes the row off the menu
-- entirely rather than offering a button that cannot do anything.
function StadiumRomPick.row()
  if not StadiumRomPick.available() then return nil end
  return {
    id = StadiumRomPick.ID,
    label = StadiumRomPick.LABEL,
    value = function()
      if StadiumInstall.status.state == "building" then return "BUILDING" end
      return StadiumInstall.available() and "READY" or "IMPORT"
    end,
    step = function(game)
      pcall(StadiumRomPick.import, game)
      return true
    end,
  }
end

return StadiumRomPick