-- lib-core.selection-test — 19 pure-state assertions for v0.1.0.
-- See meta/docs/superpowers/specs/2026-05-14-p3-6-lib-selection-design.md §5.

local selection = require("lib-core.selection")
local T         = engine.test

local M = {}

function M.run_tests(ctx)
    -- Register / Unregister (3)
    local h1 = selection.register(function() return {x=0, y=0, w=10, h=10} end)
    T.assert(h1 ~= nil and h1 >= 1, "register returns positive handle")
    T.equals(selection.count_registered(), 1, "count_registered after register")
    selection.unregister(h1)
    T.equals(selection.count_registered(), 0, "count_registered after unregister")

    -- Re-register for set-tests
    local h2 = selection.register(function() return {x=0,  y=0, w=10, h=10} end)
    local h3 = selection.register(function() return {x=20, y=0, w=10, h=10} end)
    local h4 = selection.register(function() return {x=40, y=0, w=10, h=10} end)

    -- Set-Query: initial empty (2)
    T.assert(selection.is_empty(), "is_empty after registers (no selection yet)")
    T.equals(selection.count(), 0, "count = 0 initially")

    -- Set-Mutation (5)
    selection.add(h2)
    T.assert(selection.contains(h2), "add → contains")
    T.equals(selection.count(), 1, "count = 1 after add")
    selection.remove(h2)
    T.assert(not selection.contains(h2), "remove → !contains")
    selection.toggle(h3); T.assert(selection.contains(h3), "toggle adds when absent")
    selection.toggle(h3); T.assert(not selection.contains(h3), "toggle removes when present")
    selection.add(h2); selection.add(h4); selection.clear()
    T.assert(selection.is_empty(), "clear → empty")

    -- Unregister cleans up selection (1)
    selection.add(h2)
    selection.unregister(h2)
    T.assert(not selection.contains(h2), "unregister removes from selection")

    -- Drag-Threshold (2)
    T.equals(selection.drag_threshold(), 4, "default threshold = 4")
    selection.set_drag_threshold(8)
    T.equals(selection.drag_threshold(), 8, "set_drag_threshold writes")

    -- Drag-State + box_rect (2)
    T.equals(selection.drag_state(), "idle", "initial drag_state = idle")
    T.assert(selection.box_rect() == nil, "box_rect nil while idle")

    -- Enabled-Flag (2)
    T.assert(selection.enabled(), "enabled default true")
    selection.set_enabled(false)
    T.assert(not selection.enabled(), "set_enabled(false) writes")
    selection.set_enabled(true)

    -- Visual-Setters (2)
    selection.set_drag_box_color(10, 20, 30, 40)
    local c = selection.drag_box_color()
    T.assert(c[1]==10 and c[2]==20 and c[3]==30 and c[4]==40,
             "set_drag_box_color writes correctly")
    selection.set_highlight_color(50, 60, 70, 80)
    local hc = selection.highlight_color()
    T.assert(hc[1]==50 and hc[2]==60 and hc[3]==70 and hc[4]==80,
             "set_highlight_color writes correctly")

    -- Error-Handling (1)
    local ok = pcall(function() selection.set_drag_threshold(-1) end)
    T.assert(not ok, "set_drag_threshold(-1) errors")
end

return M