-- =====================================================================
-- lib-core.maps-test — Reference test-module (P.3.1)
-- Validates lib-core.maps API contracts via engine.test.* assertions.
-- See: meta/docs/superpowers/specs/2026-05-10-test-module-pattern-design.md
-- =====================================================================
local maps = require("lib-core.maps")

function init(ctx)
    -- Setup
    local demo_map = maps.load("maps/demo.map.json")
    maps.set_current(demo_map)

    -- Geometry assertions
    local size = maps.size()
    engine.test.equals(size.w, 16, "map width = 16")
    engine.test.equals(size.h, 16, "map height = 16")
    engine.test.equals(maps.tile_size(), 32, "tile_size = 32")

    -- Tile lookup + walkability
    engine.test.equals(maps.tile_at(0, 0).id,  "stone", "tile_at(0,0) is stone")
    engine.test.equals(maps.tile_at(5, 5).id,  "grass", "tile_at(5,5) is grass")
    engine.test.assert(not maps.is_walkable(0, 0), "stone border non-walkable")
    engine.test.assert(maps.is_walkable(5, 5),     "grass interior walkable")

    -- Arity-flex tile_at: 3-arg with nil map_id falls back to current_map (P.2.1)
    engine.test.equals(maps.tile_at(nil, 5, 5).id, "grass", "tile_at 3-arg nil-fallback")

    -- Out-of-bounds returns nil
    engine.test.equals(maps.tile_at(-1, 0), nil, "tile_at OOB negative tx returns nil")
    engine.test.equals(maps.tile_at(0, 16), nil, "tile_at OOB ty=size.h returns nil")

    -- list() returns registered map-id
    local list = maps.list()
    engine.test.equals(#list, 1, "maps.list returns 1 registered map")

    engine.exit(engine.test.failures())
end