-- Stand-in for the firmware bindings, so host tests exercise the real ui.lua.
--
-- One definition of the binding surface: when a binding is added or renamed, this is
-- the file that changes. Tests mutate the returned table to steer the device, and may
-- overwrite any stub function outright for a single assertion.

local device = {
  -- Text metrics chosen to match the firmware's default GLCD font, since layout
  -- assertions are written in real pixels.
  fontHeight = 8,
  charWidth = 6,
  now = 0,
  rotation = 0,
  theme = "light",
  clockSynced = false,
  tickInterval = 0,
  appName = "test",
  textSize = 1,
  fullscreen = false,
  timezone = "UTC0",
  raw = nil, -- pending raw touch reading, {x, y} or nil
  networks = {}, -- what wifi.scan() returns
  bleDevices = {}, -- what ble.scan() returns
  status = { state = "disconnected", ssid = "", ip = "", rssi = 0 },
  painted = {}, -- every drawText call, in order
  calibration = nil, -- last settings.setCalibration()
  freeHeap = 200000,
  totalHeap = 320000,
  largestBlock = 100000,
  connected = nil, -- last wifi.connect()
  backed = false,
  launched = nil, -- last sys.launch()/replace(), {path, arg, replace}
  saveFails = false, -- make every persisting call report failure
}

local function saved()
  return not device.saveFails
end

function device.install()
  device.painted = {}
  device.lines = {}
  device.roundRects = {}
  device.files = device.files or {}
  device.timers = {}
  device.nextTimer = 1

  -- The widget tree lives in the firmware. Geometry -- layout, hit testing, style
  -- inheritance -- is asserted in test/ui_layout_test.cpp against the same C++ the panel
  -- runs, so this fake deliberately implements none of it. What it does keep is the
  -- structure an app builds, which is what app logic is actually about: a test taps the
  -- control labelled "Rotation" rather than the pixel it happened to land on.
  local nodes = {}
  device.nodes = nodes
  device.drawn = 0
  device.tapTarget = nil

  node = setmetatable({
    reset = function()
      for index in ipairs(nodes) do
        nodes[index] = nil
      end
    end,
    create = function(parent, spec)
      nodes[#nodes + 1] = {
        parent = parent,
        label = spec.label,
        kind = spec.type,
        interactive = spec.interactive or spec.capture,
      }
      return #nodes
    end,
    attach = function(parent, child)
      nodes[child].parent = parent
    end,
    getParent = function(id)
      return nodes[id].parent
    end,
    getLabel = function(id)
      return nodes[id].label
    end,
    setLabel = function(id, text)
      nodes[id].label = text
    end,
    getCount = function()
      return #nodes
    end,
    layout = function()
      return true
    end,
    -- Any point is inside, because which node a point covers is geometry and geometry is
    -- not this file's business. Tests choose the target with device.tap().
    getRect = function()
      return 0, 0, 10000, 10000
    end,
    hit = function()
      return device.tapTarget
    end,
    draw = function()
      device.drawn = device.drawn + 1
    end,
  }, {
    __index = function()
      return function() end
    end,
  })

  gui = {
    -- Font roles are scales of the one built-in font, matching the firmware's GuiProvider.
    FONT_SMALL = 1,
    FONT_UI = 2,
    FONT_BODY = 2,
    FONT_LARGE = 3,
    STYLE_NORMAL = 0,
    STYLE_BOLD = 0,
    color = function(r, g, b)
      return r * 65536 + g * 256 + b
    end,
    -- Rotation swaps the frame, exactly as TFT_eSPI reports it.
    getWidth = function()
      return device.rotation % 180 == 0 and 320 or 480
    end,
    getHeight = function()
      return device.rotation % 180 == 0 and 480 or 320
    end,
    clear = function() end,
    fillRect = function() end,
    drawRect = function() end,
    fillCircle = function() end,
    drawLine = function(...)
      device.lines[#device.lines + 1] = { ... }
    end,
    roundRect = function(...)
      device.roundRects[#device.roundRects + 1] = { ... }
    end,
    drawPixel = function() end,
    drawCircle = function() end,
    fillPolygon = function() end,
    drawBmp = function()
      return nil, "no decoder"
    end,
    drawText = function(font, x, y, label)
      device.painted[#device.painted + 1] = { label = label, x = x, y = y, font = font }
    end,
    getFontHeight = function(font)
      return device.fontHeight * (font or 1)
    end,
    getTextWidth = function(font, text)
      return #text * device.charWidth * (font or 1)
    end,
    setRotation = function(degrees)
      device.rotation = degrees
    end,
    getRotation = function()
      return device.rotation
    end,
    setFullscreen = function(on)
      device.fullscreen = on and true or false
    end,
  }

  sys = {
    getMillis = function()
      return device.now
    end,
    back = function()
      device.backed = true
    end,
    getAppID = function()
      return device.appName
    end,
    getAppTitle = function()
      return device.appName
    end,
    setAppTitle = function(name)
      device.appName = name
    end,
    getAppDataPath = function()
      return "/.lua/data/" .. device.appName
    end,
    getAPIVersion = function()
      return 1
    end,
    hasFeature = function(name)
      return name == "touch"
    end,
    getMemory = function()
      return device.freeHeap, device.totalHeap, device.largestBlock
    end,
    isClockSynced = function()
      return device.clockSynced
    end,
    launch = function(path, arg)
      device.launched = { path = path, arg = arg, replace = false }
    end,
    replace = function(path, arg)
      device.launched = { path = path, arg = arg, replace = true }
    end,
  }

  settings = {
    getRotation = function()
      return device.rotation
    end,
    setRotation = function(degrees)
      if degrees % 90 ~= 0 or degrees < 0 or degrees > 270 then
        return false
      end
      device.rotation = degrees
      return saved()
    end,
    setCalibration = function(...)
      device.calibration = { ... }
      return saved()
    end,
    getTimezone = function()
      return device.timezone
    end,
    setTimezone = function(tz)
      device.timezone = tz
      return saved()
    end,
  }

  input = {
    isTouched = function()
      return device.raw ~= nil
    end,
    getTouch = function()
      if not device.raw then
        return nil
      end
      return device.raw[1], device.raw[2]
    end,
    getRawTouch = function()
      if not device.raw then
        return nil
      end
      return device.raw[1], device.raw[2]
    end,
  }

  fs = {
    MAX_READ_BYTES = 65536,
    -- ui.lua persists the theme through fs, so the files table is real storage.
    readFile = function(path)
      return device.files[path]
    end,
    writeFile = function(path, value)
      if device.saveFails then
        return nil, "read only"
      end
      device.files[path] = value
      return true
    end,
    exists = function(path)
      return device.files[path] ~= nil
    end,
    listFiles = function()
      return {}
    end,
    listDirs = function()
      return {}
    end,
    fileSize = function(path)
      local value = device.files[path]
      return value and #value or nil, value and nil or "missing"
    end,
  }

  -- Timers fire only when a test asks, so a callback's effect is asserted where it happens.
  timer = {
    after = function(ms, callback)
      return device.addTimer(ms, callback, false)
    end,
    every = function(ms, callback)
      return device.addTimer(ms, callback, true)
    end,
    cancel = function(id)
      local found = device.timers[id] ~= nil
      device.timers[id] = nil
      return found
    end,
  }

  wifi = {
    scan = function()
      return device.networks
    end,
    getStatus = function()
      return device.status
    end,
    connect = function(ssid, password)
      device.wifiReconnect = ssid == nil
      device.connected = { ssid, password }
      if ssid then
        device.status.ssid = ssid
      end
      device.status.state = "connecting"
      return saved()
    end,
    disconnect = function()
      device.status.state = "disconnected"
    end,
    forget = function()
      device.connected = nil
      device.status = { state = "disconnected", ssid = "", ip = "", rssi = 0 }
      return saved()
    end,
  }

  ble = {
    init = function(name)
      device.bleInitialized, device.bleName = true, name
      return true
    end,
    deinit = function()
      device.bleInitialized = false
      device.bleName, device.bleConnected, device.bleAdvertising = nil, nil, nil
    end,
    isInitialized = function()
      return device.bleInitialized == true
    end,
    scan = function()
      return device.bleDevices
    end,
    connect = function(address)
      device.bleConnected = address
      return true
    end,
    disconnect = function()
      device.bleConnected = nil
    end,
    isConnected = function()
      return device.bleConnected ~= nil
    end,
    read = function()
      return "test"
    end,
    write = function(service, characteristic, value)
      device.bleWrite = { service, characteristic, value }
      return true
    end,
    startAdvertising = function(name)
      device.bleAdvertising = name
      return true
    end,
    stopAdvertising = function()
      device.bleAdvertising = nil
    end,
  }

  log = { debug = function() end, info = function() end, error = function() end }

  return device
end

-- The first node whose text starts with `prefix`, whether or not anything can press it.
function device.labelled(prefix)
  for id, entry in ipairs(device.nodes) do
    if entry.label and entry.label:sub(1, #prefix) == prefix then
      return id
    end
  end
end

-- The nearest ancestor of that text that can be pressed: a card's label is a child of the
-- button, and it is the button a finger lands on.
function device.find(prefix)
  for id, entry in ipairs(device.nodes) do
    if entry.label and entry.label:sub(1, #prefix) == prefix then
      local target = id
      while target and not device.nodes[target].interactive do
        target = device.nodes[target].parent
      end
      if target then
        return target
      end
    end
  end
end

-- Presses the control labelled `prefix`, the way a test means it: by what it says, not by
-- where it landed.
-- Registers a timer and hands back its id, mirroring timer.after/every.
function device.addTimer(intervalMs, callback, repeating)
  local id = device.nextTimer
  device.nextTimer = id + 1
  device.timers[id] = { callback = callback, intervalMs = intervalMs, repeating = repeating }
  return id
end

-- Fires every registered timer once, which is what a test means by "time passed".
function device.fireTimers()
  for id, entry in pairs(device.timers) do
    if not entry.repeating then
      device.timers[id] = nil
    end
    entry.callback()
  end
end

function device.tap(prefix)
  local target = device.find(prefix)
  if not target then
    error("no control labelled '" .. prefix .. "'", 2)
  end
  device.press(target, 0, 0)
end

-- Presses a node at a point, for the widgets that have no label to aim at. getRect()
-- answers the same box here as it does inside the widget, so a custom painter's own
-- geometry decides what was hit, exactly as it does on the panel.
function device.press(id, x, y)
  device.tapTarget = id
  on_touch_down(x, y)
  on_touch_up(x, y)
  device.tapTarget = nil
end

function device.findKind(kind)
  for id, entry in ipairs(device.nodes) do
    if entry.kind == kind then
      return id
    end
  end
end

return device