card.gno

 1// Package engine holds the duel rules. The same source compiles as Go and as Gno, so it
 2// stays inside the Go 1.17 subset: no generics, no min or max builtins, no range over
 3// an integer, no maps and no imports.
 4package engine
 5
 6const beatsPerRound = 3
 7
 8// Tier orders effects inside a phase.
 9type Tier int
10
11const (
12	Quick Tier = iota
13	Normal
14	Slow
15)
16
17type EffectKind int
18
19const (
20	GainBlock EffectKind = iota
21	GainCounter
22	Hit      // deal N damage
23	HitBlock // deal damage equal to your Block
24	ApplyVulnerable
25	GainStrength
26	VulnerableIfCancelled // apply N Vulnerable if this card cancelled a card this beat
27	MoveVulnerable        // Block phase: move all your Vulnerable to the opponent
28	GainVulnerable        // gain N Vulnerable yourself
29	HitPerVulnerable      // deal N damage, and N more for each Vulnerable on you
30	BlockPerVulnerable    // Block phase: gain N Block, and N more for each Vulnerable on you
31	StripBlock            // the opponent loses all Block at the end of the step
32	HitHardest            // deal the HP the hardest opponent hit took from you this round, up to N
33	HitIfNotAttacked      // deal N damage if no opponent attack lands this beat
34)
35
36type Effect struct {
37	Kind EffectKind
38	N    int
39}
40
41// CardID indexes Ruleset.Cards.
42type CardID int
43
44type Card struct {
45	Name      string
46	Cost      int
47	Tier      Tier
48	Special   bool // spent once played; basics are not
49	Rare      bool // the clan's signature card; a deck holds exactly one
50	Interrupt bool
51	Parry     int      // Parry N: attacks it cancels while active; 0 for no Parry
52	Block     []Effect // Block phase
53	Damage    []Effect // Damage phase, in printed order
54	OnCancel  []Effect // Block phase of the beat the card is cancelled on
55	// CancelDamage resolves in the card's tier, in the Damage phase of the beat it is
56	// cancelled on.
57	CancelDamage []Effect
58}
59
60// Attack reports whether the card's text deals damage, including when it is cancelled.
61func (c *Card) Attack() bool {
62	return dealsDamage(c.Damage) || dealsDamage(c.CancelDamage)
63}
64
65func dealsDamage(effects []Effect) bool {
66	for _, e := range effects {
67		if e.Kind.isHit() {
68			return true
69		}
70	}
71	return false
72}
73
74func (k EffectKind) isHit() bool {
75	return k == Hit || k == HitBlock || k == HitPerVulnerable || k == HitHardest || k == HitIfNotAttacked
76}
77
78// Plan is the ordered cards of one round; their costs sum to 3.
79type Plan []CardID
80
81type Side int
82
83const (
84	SideA Side = iota
85	SideB
86)