-- Run: lua test/ui_layout.lua
-- Asserts the rects ui.lua computes, against the shared fake device.
package.path = "sdcard/lib/?.lua;test/?.lua;" .. package.path

local device = require("fake_device").install()
local ui = require("ui")

local function rect(node)
  return string.format("%d,%d %dx%d", node.rect.x, node.rect.y, node.rect.w, node.rect.h)
end

-- Vertical flow: children fill the content width, stack by their own height plus gap.
local title = ui.text("settings")
local first = ui.button{label = "one", on_press = function() end}
local second = ui.button{label = "two", on_press = function() end}
local screen = ui.screen(ui.box{pad = 12, gap = 8, title, first, second})

assert(rect(title) == "12,12 296x8", rect(title))
-- Button height is text plus its own padding: 8 + 8 + 8 = 24.
assert(rect(first) == "12,28 296x24", rect(first))
assert(rect(second) == "12,60 296x24", rect(second))

-- Fractions resolve against the parent content box, absolutes stay absolute.
local half = ui.box{w = 0.5, h = 40}
local fixed = ui.box{w = 100, h = 40}
ui.screen(ui.box{pad = 10, half, fixed})
assert(rect(half) == "10,10 150x40", rect(half))
assert(rect(fixed) == "10,50 100x40", rect(fixed))

-- Horizontal flow with centre alignment on the cross axis of a fixed-height row.
local tall = ui.box{w = 40, h = 40}
local short = ui.box{w = 40, h = 10}
local row = ui.box{row = true, gap = 6, align = "center", h = 40, tall, short}
ui.screen(ui.box{row})
assert(rect(tall) == "0,0 40x40", rect(tall))
assert(rect(short) == "46,15 40x10", rect(short))

-- justify distributes the main axis: "between" pushes the last child to the far edge,
-- which is how a header keeps a title left and a clock right without arithmetic.
local left = ui.box{w = 40, h = 10}
local right = ui.box{w = 60, h = 10}
ui.screen(ui.box{pad = 10, ui.box{row = true, justify = "between", left, right}})
assert(rect(left) == "10,10 40x10", rect(left))
assert(rect(right) == "250,10 60x10", rect(right))

-- The other modes shift the whole run rather than spreading it.
local a = ui.box{w = 40, h = 10}
local b = ui.box{w = 60, h = 10}
ui.screen(ui.box{ui.box{row = true, gap = 10, justify = "end", a, b}})
assert(rect(a) == "210,0 40x10", rect(a))
assert(rect(b) == "260,0 60x10", rect(b))

-- One child cannot be spread against anything, so "between" degrades to "start".
local only = ui.box{w = 40, h = 10}
ui.screen(ui.box{ui.box{row = true, justify = "between", only}})
assert(rect(only) == "0,0 40x10", rect(only))

-- The root always fills the screen, so alignment there spans the whole panel.
local lone = ui.box{w = 40, h = 40}
ui.screen(ui.box{align = "center", lone})
assert(rect(lone) == "140,0 40x40", rect(lone))

-- A fraction inside an auto-sized parent is a build-time error, not a silent zero.
local ok = pcall(function()
  ui.screen(ui.box{ui.box{h = "auto", ui.box{w = 20, h = 0.5}}})
end)
assert(not ok, "fraction inside an auto parent must fail loudly")

-- Hit testing: deepest interactive component wins over its tappable ancestor.
local inner = ui.button{label = "inner", on_press = function() end}
local outer = ui.box{pad = 20, on_press = function() end, inner}
local nested = ui.screen(outer)
assert(outer:hit(160, 30) == inner, "inner button should win inside its rect")
assert(outer:hit(2, 2) == outer, "the container claims its own padding")
assert(outer:hit(-50, -50) == nil, "outside the tree is a miss")

-- Capture: press then release outside cancels; release inside fires once.
local fired = 0
local button = ui.button{label = "go", on_press = function() fired = fired + 1 end}
local app = ui.screen(ui.box{pad = 10, button})
app:down(100, 20)
assert(button.pressed, "press must show immediately")
app:up(300, 470)
assert(fired == 0, "release outside must cancel")

app:down(100, 20)
app:up(100, 20)
assert(fired == 1, "release inside must fire once")

-- The pressed look is held briefly, then cleared on a later draw.
assert(button.pressed, "pressed look must outlast the release")
device.now = device.now + 100
app:draw()
assert(not button.pressed, "pressed look must clear after the hold")

print("ok")