-- 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
  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 = {}

  -- 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 = {
    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() end,
    roundRect = function() end,
    drawText = function(label, x, y)
      device.painted[#device.painted + 1] = {label = label, x = x, y = y}
    end,
    setTextSize = function(size) device.textSize = size end,
    getFontHeight = function() return device.fontHeight * device.textSize end,
    getTextWidth = function(text) return #text * device.charWidth * device.textSize 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,
    getAppName = function() return device.appName end,
    setAppName = function(name) device.appName = name end,
    getMemory = function() return device.freeHeap, device.totalHeap, device.largestBlock end,
    isClockSynced = function() return device.clockSynced end,
    setTickInterval = function(ms)
      assert(ms == 0 or on_tick, "setTickInterval without on_tick")
      device.tickInterval = ms
    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,
    getTheme = function() return device.theme end,
    setTheme = function(name) device.theme = name 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 = {
    readFile = function() return nil end,
    writeFile = function() return saved() end,
    exists = function() return false end,
    listFiles = function() return {} end,
    listDirs = function() return {} end,
  }

  wifi = {
    scan = function() return device.networks end,
    getStatus = function() return device.status end,
    connect = function(ssid, password)
      device.connected = {ssid, password}
      return saved()
    end,
    forget = function() device.connected = nil return saved() 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.
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