gogobee/internal/plugin/adventure_flavor_campaign.go

package plugin

import (
	"fmt"
	"math/rand/v2"
	"strings"

	"maunium.net/go/mautrix/id"
)

// The Hollow King campaign (N5/D1). A light serialized story threaded through
// the zones by way of collectible journal pages. "The Hollow King" is already
// the Forest Shadows (T2) boss; this frames him as a realm-spanning antagonist
// whose fragments turn up wherever players fight elites and open secret rooms.
//
// The fragments are in-world found artifacts — journal entries, torn letters,
// stone inscriptions — not TwinBee's voice. TwinBee's own reactions (D1b) obey
// the first-person voice rules; this text does not.

type journalPage struct {
	Title string
	Text  string
}

// journalPages is the ordered campaign. Reading the discovered pages top to
// bottom tells the fall of a kingdom to the thing its king became. Order is the
// story order; players find them out of sequence, which is why the viewer marks
// gaps.
var journalPages = []journalPage{
	{"The Long Winter", "A crown is only a circle of gold until a man decides never to take it off. Ours decided in a winter that would not end, and the frost took its cue from him."},
	{"The Last Physician", "The court healers were sent home one by one, each promising the king had years left. The last was not sent home. We heard him thank the king for the honour."},
	{"On Shadows", "He stopped casting a shadow before he stopped casting a reflection. The steward struck both from the list of things a servant may notice aloud."},
	{"The Quiet Ledger", "Grain still left the granaries; no mouths were fed. I stopped auditing the difference the night the number began to feel like a name."},
	{"A Bargain Overheard", "Through the chapel door: the king's voice, and a second that used his own words a breath before he did. Only one of them was asking."},
	{"The Hollowing", "They call it a coronation in the records. Those of us who carried the braziers call it what it was. A king was emptied so a crown could keep wearing him."},
	{"The First Knights", "His honour guard did not die. That was the mercy offered and the price paid. They stand at the old gate yet, and they still salute a throne no living thing sits on."},
	{"Letters Home, Unsent", "\"Tell mother the pay is good and the work is guarding.\" The satchel held forty such letters, every hand different, every promise the same, none of them sent."},
	{"The Map Redrawn", "The kingdom did not fall so much as come apart at the seams — a warren here, a drowned temple there, each piece keeping a splinter of him like a tooth in a wound."},
	{"Root and Rot", "The forest north of the manor grew wrong and grew fast. The woodsmen say the trees lean toward the ruin at dusk. The woodsmen no longer go at dusk."},
	{"The Warren Below", "Even the goblins gave the deep tunnels to him and asked nothing back. When a scavenger yields ground for free, ask what it saw down there."},
	{"Water That Remembers", "The temple sank in a single night with the bells still ringing. Divers say the bells ring still, slow, as if something below is counting."},
	{"The Manor's Long Guest", "Blackspire changed hands nine times in a decade. Every deed names a different owner. Every household names the same tenant, and none will write it down."},
	{"The Forge Unbanked", "The underforge keeps a heat with no fuel and no smith. What it makes, no one has seen leave. What it makes, we are told, was promised elsewhere long ago."},
	{"Descent", "The deep roads were a trade route once. Now they are a throat. Everything the surface loses is swallowed the same direction, and the direction has a door at the end."},
	{"The Bright Country", "Past the crossing the colours are too kind and the days too long. It is the most beautiful place I have run from. He is patient there; he can afford to be."},
	{"What the Dragon Keeps", "The wyrm hoards more than gold. Deep in the lair, behind the coin, a single crown sits on no head and is guarded better than the hoard."},
	{"The Portal's Arithmetic", "The abyss gate opens outward. Everyone assumes a door lets things in. This one was built by someone who only ever intended to leave through it."},
	{"The Regent's Confession", "I ruled in his name for thirty years and never once saw him rule. I signed what the crown wanted signed. I am writing this so that one honest page exists."},
	{"The Names of the Guard", "I have set down every knight's name here so that when this is read, they are grieved as men and not feared as things. It is the only rescue left to attempt."},
	{"The Flaw in the Bargain", "The second voice took the king's life and his death both — and a thing that cannot die also cannot be finished. He is not immortal. He is unpaid, and waiting to collect."},
	{"How to Call Him", "He answers only where his fragments gather and only to one who has gathered them. Do not do this to avenge us. Do it to end the account. Come with the whole ledger or do not come."},
	{"The Empty Throne", "I have seen the seat at the heart of it all. It is not empty. It is occupied by the shape of a man who left, kept warm against his return."},
	{"Last Page", "If you are reading in order, you have walked the ruin of everything he emptied to stay. One page is missing from every telling — the one you write by going in. Bring a light. He hates the light. It is the one thing he could never hollow out."},
}

// journalTotalPages is the campaign length; the drop/viewer/finale all read it
// so the story can grow by appending to journalPages alone.
var journalTotalPages = len(journalPages)

// journalPageDropChance is the per-elite-kill probability that a page turns up.
// Deliberately modest: 24 pages is a long-horizon collection, and secret rooms
// (D4) grant pages on top of this. Tunable.
const journalPageDropChance = 0.22

// setJournalPageBit is the in-memory twin of grantJournalPageDB's bitwise OR —
// the single definition of "page N lives in bit N-1". Out-of-range pages are a
// no-op.
func setJournalPageBit(mask int64, page int) int64 {
	if page < 1 || page > 63 {
		return mask
	}
	return mask | (int64(1) << (page - 1))
}

func journalPageFound(mask int64, page int) bool {
	if page < 1 || page > 63 {
		return false
	}
	return mask&(int64(1)<<(page-1)) != 0
}

func journalPageCount(mask int64) int {
	n := 0
	for i := 1; i <= journalTotalPages; i++ {
		if journalPageFound(mask, i) {
			n++
		}
	}
	return n
}

func journalComplete(mask int64) bool {
	return journalPageCount(mask) >= journalTotalPages
}

// pickUnfoundJournalPage returns a random not-yet-found page number, or 0 when
// the campaign is already complete.
func pickUnfoundJournalPage(mask int64, rng *rand.Rand) int {
	var missing []int
	for i := 1; i <= journalTotalPages; i++ {
		if !journalPageFound(mask, i) {
			missing = append(missing, i)
		}
	}
	if len(missing) == 0 {
		return 0
	}
	return missing[rngIntN(rng, len(missing))]
}

// maybeDropJournalPage rolls a page reward for an elite kill or secret room and,
// on a hit, grants a random unfound page and returns its narration line. Empty
// string means no drop (missed the roll, DB error, or campaign already
// complete). The roll draws from the same RNG the surrounding loot rolls use
// and never touches SimulateCombat's stream, so the combat golden is unmoved.
func (p *AdventurePlugin) maybeDropJournalPage(userID id.UserID, rng *rand.Rand) string {
	if rngFloat(rng) >= journalPageDropChance {
		return ""
	}
	return p.grantJournalPage(userID, rng)
}

// grantJournalPage grants a random unfound page unconditionally (used by secret
// rooms, which award a page for certain). Returns "" when already complete or on
// error.
func (p *AdventurePlugin) grantJournalPage(userID id.UserID, rng *rand.Rand) string {
	mask, err := loadJournalPages(userID)
	if err != nil {
		return ""
	}
	page := pickUnfoundJournalPage(mask, rng)
	if page == 0 {
		return ""
	}
	if err := grantJournalPageDB(userID, page); err != nil {
		return ""
	}
	return fmt.Sprintf("📖 A torn journal page — _%s_ (page %d of %d). See `!adventure journal`.",
		journalPages[page-1].Title, page, journalTotalPages)
}

// handleJournalCmd renders the player's collected campaign pages.
func (p *AdventurePlugin) handleJournalCmd(ctx MessageContext) error {
	char, _, err := p.ensureCharacter(ctx.Sender)
	if err != nil {
		return p.SendReply(ctx.RoomID, ctx.EventID, "Failed to load your character. Try `!adventure` to create one first.")
	}
	return p.SendDM(ctx.Sender, renderJournal(char.JournalPages))
}

// renderJournal builds the `!adventure journal` view: discovered pages in story
// order, with runs of missing pages collapsed to a single "…".
func renderJournal(mask int64) string {
	found := journalPageCount(mask)
	var b strings.Builder
	b.WriteString(fmt.Sprintf("📖 **The Hollow King** — Journal (%d / %d pages)\n",
		found, journalTotalPages))

	if found == 0 {
		b.WriteString("\nYou carry no pages yet. They surface where the realm's fragments gather — in the hands of elites, and behind doors most adventurers walk past.")
		return b.String()
	}

	b.WriteString("\n")
	gapOpen := false
	for i := 1; i <= journalTotalPages; i++ {
		if journalPageFound(mask, i) {
			gapOpen = false
			jp := journalPages[i-1]
			b.WriteString(fmt.Sprintf("\n**%s. %s**\n%s\n", romanNumeral(i), jp.Title, jp.Text))
		} else if !gapOpen {
			gapOpen = true
			b.WriteString("\n…\n")
		}
	}

	if journalComplete(mask) {
		b.WriteString("\nThe ledger is whole. Every page you needed, you have. What remains is to bring it to him.")
	} else {
		b.WriteString(fmt.Sprintf("\n_%d pages still scattered._", journalTotalPages-found))
	}
	return b.String()
}

// romanNumeral renders 1..24 as upper-case Roman numerals for the page headers.
// The campaign never exceeds a couple dozen pages, so a small table beats a
// general algorithm here.
func romanNumeral(n int) string {
	if n < 1 || n > len(romanNumerals) {
		return fmt.Sprintf("%d", n)
	}
	return romanNumerals[n-1]
}

var romanNumerals = []string{
	"I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX", "X",
	"XI", "XII", "XIII", "XIV", "XV", "XVI", "XVII", "XVIII", "XIX", "XX",
	"XXI", "XXII", "XXIII", "XXIV", "XXV", "XXVI", "XXVII", "XXVIII", "XXIX", "XXX",
}