extends SceneTree

## Do the game modes end, and end on the RIGHT thing?
##
##     godot --headless --path . -s res://debug/game_mode_check.gd
##
## `GameMode.check_win` is a pure function of the stats and the clock, which is
## the point of writing it that way: a win condition that can only be exercised
## by playing a whole match is a win condition nobody tests, and this project's
## previous one — a five-minute timer that set `match_active = false` and did
## nothing else — was never exercised at all.
##
## The cases below are the ones that actually go wrong: a draw reported as a win
## for whoever happens to be first in a dictionary, a team mode decided on one
## player's score instead of the team's, and a team kill counting toward the
## killer.

var _fails := 0


func _init() -> void:
	# Autoloads are not up during `_init`; LoadoutManager is needed below.
	await process_frame
	_check_table()
	_check_deathmatch()
	_check_team()
	_check_gun_game()
	_check_standings()
	_done()


## Every mode must be able to end. A mode with no score limit and no time limit
## runs forever, and that is the failure that produced this whole task.
func _check_table() -> void:
	for id in GameMode.all_ids():
		_expect(GameMode.is_valid(id),
			"'%s' can end (score %d, time %.0fs)"
				% [id, GameMode.score_limit(id), GameMode.time_limit(id)])
		_expect(GameMode.display_name(id) != "",
			"'%s' has a display name" % id)
	_expect(GameMode.score_limit(GameMode.GUN_GAME) == GameMode.LADDER.size(),
		"Gun Game's limit IS its ladder length (%d), so adding a rung cannot make the match unwinnable"
			% GameMode.LADDER.size())


func _check_deathmatch() -> void:
	var id := GameMode.DEATHMATCH
	var limit := GameMode.score_limit(id)

	var mid := {1: _p("A", limit - 1), 2: _p("B", 3)}
	_expect(GameMode.check_win(id, mid, 120.0).is_empty(),
		"deathmatch keeps running one short of the limit")

	var done := {1: _p("A", limit), 2: _p("B", 3)}
	var r := GameMode.check_win(id, done, 120.0)
	_expect(r.get("reason", "") == "score" and r.get("name", "") == "A",
		"deathmatch ends when someone reaches %d, and A won" % limit)

	# On time, the leader takes it.
	var timed := GameMode.check_win(id, {1: _p("A", 7), 2: _p("B", 4)}, 0.0)
	_expect(timed.get("reason", "") == "time" and timed.get("name", "") == "A",
		"deathmatch on time goes to the leader")

	# A DRAW is a draw. Reporting a winner here means reporting whichever key
	# the dictionary happened to hand over first, which is not a rule.
	var drawn := GameMode.check_win(id, {1: _p("A", 5), 2: _p("B", 5)}, 0.0)
	_expect(drawn.get("name", "") == "DRAW",
		"a tie on time is a DRAW, not a win for whoever is first in the dictionary")


func _check_team() -> void:
	var id := GameMode.TEAM_DEATHMATCH
	var limit := GameMode.score_limit(id)

	# Two on team 1 with half the limit each: the TEAM has won, though neither
	# player is close on their own. Deciding this on individual score — which is
	# what a per-player check would do — never ends a team match.
	var half := int(limit / 2.0)
	var stats := {
		1: _p("A", half, 1), 2: _p("B", half, 1),
		3: _p("C", 4, 2), 4: _p("D", 4, 2),
	}
	var r := GameMode.check_win(id, stats, 300.0)
	_expect(r.get("reason", "") == "score" and r.get("team", 0) == 1,
		"team deathmatch is decided by the TEAM's total, not one player's")

	var totals := GameMode.team_scores(id, stats)
	_expect(totals.get(1, 0) == half * 2 and totals.get(2, 0) == 8,
		"team totals add up (%d / %d)" % [totals.get(1, 0), totals.get(2, 0)])

	# Balance on join, by count and not by turn — a 4v4 that loses three from one
	# side must refill the short side, which round-robin on join order does not.
	var lopsided := {1: _p("A", 0, 1), 2: _p("B", 0, 1), 3: _p("C", 0, 1)}
	_expect(GameMode.assign_team(id, lopsided) == 2,
		"a joining player goes to the SHORT team")

	var tied := GameMode.check_win(id, {1: _p("A", 5, 1), 2: _p("B", 5, 2)}, 0.0)
	_expect(tied.get("name", "") == "DRAW", "level teams on time is a DRAW")


func _check_gun_game() -> void:
	var id := GameMode.GUN_GAME
	var top := GameMode.LADDER.size()

	_expect(GameMode.check_win(id, {1: _p("A", top - 1)}, 300.0).is_empty(),
		"gun game keeps running on the last rung")
	var r := GameMode.check_win(id, {1: _p("A", top)}, 300.0)
	_expect(r.get("reason", "") == "score",
		"gun game ends when someone finishes the ladder")

	# Every rung must name a weapon that exists, or a promotion hands the player
	# nothing and the mode softlocks on that rung.
	#
	# Reached through the tree rather than by the autoload's global identifier: a
	# `-s` tool script compiles its dependencies BEFORE autoloads register, so
	# naming `LoadoutManager` directly stops this file from loading at all.
	var loadouts = root.get_node_or_null("LoadoutManager")
	for i in GameMode.LADDER.size():
		var w := GameMode.ladder_weapon(i)
		_expect(loadouts != null and loadouts.weapon_db.has(w),
			"ladder rung %d ('%s') is a real weapon" % [i, w])

	# Past the end clamps rather than going out of bounds — the winning kill
	# promotes past the top rung before the match-end RPC lands.
	_expect(GameMode.ladder_weapon(999) == GameMode.LADDER[-1],
		"promoting past the top rung clamps instead of erroring")


func _check_standings() -> void:
	var stats := {
		1: _p("A", 5), 2: _p("B", 9), 3: _p("C", 5),
	}
	stats[1]["deaths"] = 2
	stats[3]["deaths"] = 7
	var order := GameMode.standings(stats)
	_expect(order[0] == 2, "standings put the highest score first")
	_expect(order[1] == 1 and order[2] == 3,
		"equal scores break on FEWEST DEATHS (kills are equal by definition there)")


func _p(who: String, score: int, team: int = 0) -> Dictionary:
	return {"username": who, "score": score, "kills": score, "deaths": 0,
		"assists": 0, "team": team, "best_streak": 0, "rung": score}


func _expect(ok: bool, what: String) -> void:
	if ok:
		print("  OK: ", what)
	else:
		print("  FAIL: ", what)
		_fails += 1


func _done() -> void:
	print("\n=== GAME MODE SUMMARY ===")
	print("Failures: %d" % _fails)
	quit(1 if _fails > 0 else 0)