core2026/packages/logic/src/diplomacy/index.ts

import { clamp } from 'es-toolkit';

// 외교 상태 코드 (legacy 기준).
export const DIPLOMACY_STATE = {
    WAR: 0,
    DECLARATION: 1,
    TRADE: 2,
    NON_AGGRESSION: 7,
} as const;

export const DEFAULT_DECLARE_WAR_TERM = 24;
export const DEFAULT_WAR_TERM = 6;

// TODO: 불가침 제의/수락 등 외교 커맨드 전환 규칙을 이 모듈에 추가 예정.
const MAX_WAR_TERM = 13;

export interface DiplomacyEntry {
    fromNationId: number;
    toNationId: number;
    state: number;
    term: number;
    dead: number;
    meta: Record<string, unknown>;
}

export interface DiplomacyPatch {
    state?: number;
    term?: number;
    dead?: number;
    deadDelta?: number;
    meta?: Record<string, unknown>;
}

export const buildDiplomacyKey = (
    srcNationId: number,
    destNationId: number
): string => `${srcNationId}:${destNationId}`;

export const buildDefaultDiplomacy = (
    srcNationId: number,
    destNationId: number
): DiplomacyEntry => ({
    fromNationId: srcNationId,
    toNationId: destNationId,
    state: DIPLOMACY_STATE.TRADE,
    term: 0,
    dead: 0,
    meta: {},
});

export const applyDiplomacyPatch = (
    entry: DiplomacyEntry,
    patch: DiplomacyPatch
): DiplomacyEntry => {
    const nextDead =
        typeof patch.dead === 'number'
            ? patch.dead
            : typeof patch.deadDelta === 'number'
            ? entry.dead + patch.deadDelta
            : entry.dead;
    return {
        ...entry,
        state: patch.state ?? entry.state,
        term: patch.term ?? entry.term,
        dead: clamp(nextDead, 0, Number.MAX_SAFE_INTEGER),
        meta: patch.meta ? { ...entry.meta, ...patch.meta } : entry.meta,
    };
};

export const readDiplomacyMeta = (
    meta: Record<string, unknown>
): { meta: Record<string, unknown>; dead: number } => {
    const rawDead = meta.dead;
    const dead = typeof rawDead === 'number' ? rawDead : 0;
    const cleaned = { ...meta };
    delete cleaned.dead;
    return { meta: cleaned, dead };
};

export const buildDiplomacyMeta = (
    entry: DiplomacyEntry
): Record<string, unknown> => ({
    ...entry.meta,
    dead: entry.dead,
});


export const processDiplomacyMonth = (
    diplomacy: DiplomacyEntry[],
    generalCounts: Map<number, number>
): DiplomacyEntry[] => {
    const next = diplomacy.map((entry) => ({
        ...entry,
        meta: { ...entry.meta },
    }));
    const byKey = new Map<string, DiplomacyEntry>(
        next.map((entry) => [
            buildDiplomacyKey(entry.fromNationId, entry.toNationId),
            entry,
        ])
    );

    // 전쟁 기간 갱신: 사상자에 따라 term 증가, 잔여 사상자 유지.
    for (const entry of next) {
        if (entry.state !== DIPLOMACY_STATE.WAR || entry.dead <= 0) {
            continue;
        }
        const genCount = Math.max(1, generalCounts.get(entry.fromNationId) ?? 1);
        const termIncrease = Math.floor(entry.dead / 100 / genCount);
        if (termIncrease <= 0) {
            continue;
        }
        entry.dead -= termIncrease * 100 * genCount;
        entry.term = clamp(entry.term + termIncrease, 0, MAX_WAR_TERM);
    }

    // 전쟁 종료 판정: 양방 term이 1 이하이면 통상으로 전환.
    const processedPairs = new Set<string>();
    for (const entry of next) {
        if (entry.state !== DIPLOMACY_STATE.WAR || entry.term > 1) {
            continue;
        }
        const pairKey = buildDiplomacyKey(
            Math.min(entry.fromNationId, entry.toNationId),
            Math.max(entry.fromNationId, entry.toNationId)
        );
        if (processedPairs.has(pairKey)) {
            continue;
        }
        const opposite = byKey.get(
            buildDiplomacyKey(entry.toNationId, entry.fromNationId)
        );
        if (
            opposite &&
            opposite.state === DIPLOMACY_STATE.WAR &&
            opposite.term <= 1
        ) {
            entry.state = DIPLOMACY_STATE.TRADE;
            entry.term = 0;
            opposite.state = DIPLOMACY_STATE.TRADE;
            opposite.term = 0;
            processedPairs.add(pairKey);
        }
    }

    // 사상자 초기화 및 term 감소.
    for (const entry of next) {
        if (entry.state !== DIPLOMACY_STATE.WAR) {
            entry.dead = 0;
        }
        entry.term = Math.max(0, entry.term - 1);
    }

    // 불가침/선전포고 만료 처리.
    for (const entry of next) {
        if (
            entry.state === DIPLOMACY_STATE.NON_AGGRESSION &&
            entry.term === 0
        ) {
            entry.state = DIPLOMACY_STATE.TRADE;
        } else if (
            entry.state === DIPLOMACY_STATE.DECLARATION &&
            entry.term === 0
        ) {
            entry.state = DIPLOMACY_STATE.WAR;
            entry.term = DEFAULT_WAR_TERM;
        }
    }

    return next;
};