import { execFileSync } from 'node:child_process';
import fs from 'node:fs';
import path from 'node:path';

import { LiteHashDRBG, RandUtil, type RNG } from '@sammo-ts/common';
import {
    ITEM_KEYS,
    DOMESTIC_TRAIT_KEYS,
    NATION_TRAIT_KEYS,
    PERSONALITY_TRAIT_KEYS,
    WAR_TRAIT_KEYS,
    loadDomesticTraitModules,
    loadItemModules,
    loadNationTraitModules,
    loadPersonalityTraitModules,
    loadWarTraitModules,
    type UnitSetDefinition,
    type WarBattleTraceEvent,
    type WarEngineConfig,
} from '@sammo-ts/logic';
import { describe, expect, it } from 'vitest';

import { processBattleSimJob } from '../../../app/game-api/src/battleSim/processor.js';
import type { BattleSimJobPayload, BattleSimRequestPayload } from '../../../app/game-api/src/battleSim/types.js';

interface ReferenceTrace {
    engine: 'ref';
    conquered: boolean;
    events: WarBattleTraceEvent[];
    rng: RandomCall[];
}

interface RandomCall {
    seq: number;
    operation: string;
    arguments: Record<string, unknown>;
    result: unknown;
}

interface ReferenceItemMetadata {
    rawName: string;
    name: string;
    info: string;
    cost: number | null;
    buyable: boolean;
    consumable: boolean;
    reqSecu: number;
}

type ReferenceTraitCatalog = Record<
    'nation' | 'domestic' | 'war' | 'personality',
    Record<string, { name: string; info: string }>
>;

class TracingRng implements RNG {
    public readonly calls: RandomCall[] = [];

    public constructor(private readonly inner: RNG) {}

    public getMaxInt(): number {
        return this.inner.getMaxInt();
    }

    public nextBytes(bytes: number): Uint8Array<ArrayBuffer> {
        const result = this.inner.nextBytes(bytes);
        this.record('nextBytes', { bytes }, Buffer.from(result).toString('hex'));
        return result;
    }

    public nextBits(bits: number): Uint8Array<ArrayBuffer> {
        const result = this.inner.nextBits(bits);
        this.record('nextBits', { bits }, Buffer.from(result).toString('hex'));
        return result;
    }

    public nextInt(max?: number): number {
        const result = this.inner.nextInt(max);
        this.record('nextInt', { maxInclusive: max ?? null }, result);
        return result;
    }

    public nextFloat1(): number {
        const result = this.inner.nextFloat1();
        this.record('nextFloat1', {}, result);
        return result;
    }

    private record(operation: string, args: Record<string, unknown>, result: unknown): void {
        this.calls.push({ seq: this.calls.length, operation, arguments: args, result });
    }
}

const findWorkspaceRoot = (start: string): string | null => {
    let current = path.resolve(start);
    while (true) {
        if (
            fs.existsSync(path.join(current, 'docker_compose_files/reference/compose.yml')) &&
            fs.existsSync(path.join(current, 'ref/sam/hwe/compare/battle_trace.php'))
        ) {
            return current;
        }
        const parent = path.dirname(current);
        if (parent === current) {
            return null;
        }
        current = parent;
    }
};

const readJson = <T>(filePath: string): T => JSON.parse(fs.readFileSync(filePath, 'utf8')) as T;

const runReferenceTrace = (workspaceRoot: string, fixtureJson: string): ReferenceTrace => {
    const stdout = execFileSync(
        'docker',
        ['compose', 'exec', '-T', 'php', 'php', '/var/www/html/hwe/compare/battle_trace.php', '-'],
        {
            cwd: path.join(workspaceRoot, 'docker_compose_files/reference'),
            input: fixtureJson,
            encoding: 'utf8',
            stdio: ['pipe', 'pipe', 'pipe'],
        }
    );
    return JSON.parse(stdout) as ReferenceTrace;
};

const runReferenceItemCatalog = (workspaceRoot: string, itemKeys: string[]): Record<string, ReferenceItemMetadata> => {
    const stdout = execFileSync(
        'docker',
        ['compose', 'exec', '-T', 'php', 'php', '/var/www/html/hwe/compare/item_catalog.php'],
        {
            cwd: path.join(workspaceRoot, 'docker_compose_files/reference'),
            input: JSON.stringify(itemKeys),
            encoding: 'utf8',
            stdio: ['pipe', 'pipe', 'pipe'],
        }
    );
    return JSON.parse(stdout) as Record<string, ReferenceItemMetadata>;
};

const runReferenceTraitCatalog = (workspaceRoot: string): ReferenceTraitCatalog => {
    const stdout = execFileSync(
        'docker',
        ['compose', 'exec', '-T', 'php', 'php', '/var/www/html/hwe/compare/trait_catalog.php'],
        {
            cwd: path.join(workspaceRoot, 'docker_compose_files/reference'),
            encoding: 'utf8',
            stdio: ['pipe', 'pipe', 'pipe'],
        }
    );
    return JSON.parse(stdout) as ReferenceTraitCatalog;
};

const expectNearlyEqual = (actual: unknown, expected: unknown, label: string): void => {
    expect(typeof actual, `${label}: actual type`).toBe('number');
    expect(typeof expected, `${label}: reference type`).toBe('number');
    if (process.env['STRICT_BATTLE_PARITY'] === '1') {
        expect(actual, `${label}: exact battle parity`).toBe(expected);
        return;
    }
    const reference = expected as number;
    const tolerance = Math.max(1, Math.abs(reference) * 0.01);
    expect(
        Math.abs((actual as number) - reference),
        `${label}: core=${String(actual)}, ref=${String(expected)}, tolerance=${tolerance}`
    ).toBeLessThanOrEqual(tolerance);
};

const assertTraceParity = (
    coreEvents: WarBattleTraceEvent[],
    reference: ReferenceTrace,
    coreRng: TracingRng | null
): void => {
    const coreEventNames = coreEvents.map((event) => event.event);
    const referenceEventNames = reference.events.map((event) => event.event);
    expect(
        coreEventNames,
        `event sequence\ncore=${JSON.stringify(coreEventNames)}\nref=${JSON.stringify(referenceEventNames)}`
    ).toEqual(referenceEventNames);
    expect(coreRng?.calls.map(({ operation, result }) => ({ operation, result }))).toEqual(
        reference.rng.map(({ operation, result }) => ({ operation, result }))
    );

    for (let index = 0; index < reference.events.length; index += 1) {
        const core = coreEvents[index]!;
        const ref = reference.events[index]!;
        expectNearlyEqual(core.attacker.hp, ref.attacker.hp, `event ${index} attacker.hp`);
        expectNearlyEqual(core.attacker.warPower, ref.attacker.warPower, `event ${index} attacker.warPower`);
        if (core.defender && ref.defender) {
            expect(core.defender.kind, `event ${index} defender.kind`).toBe(ref.defender.kind);
            expectNearlyEqual(core.defender.hp, ref.defender.hp, `event ${index} defender.hp`);
            expectNearlyEqual(core.defender.warPower, ref.defender.warPower, `event ${index} defender.warPower`);
        } else {
            expect(core.defender, `event ${index} defender presence`).toBe(ref.defender);
        }
        if (core.event === 'phase_damage') {
            for (const key of ['rawDeadAttacker', 'rawDeadDefender', 'deadAttacker', 'deadDefender']) {
                expectNearlyEqual(core.details[key], ref.details[key], `event ${index} ${key}`);
            }
        }
    }
};

const workspaceRoot = findWorkspaceRoot(process.cwd());
const describeWithReference = workspaceRoot ? describe : describe.skip;

describeWithReference('ref ↔ core2026 battle differential', () => {
    it('matches every legacy trait name and description', async () => {
        const reference = runReferenceTraitCatalog(workspaceRoot!);
        const [nation, domestic, war, personality] = await Promise.all([
            loadNationTraitModules([...NATION_TRAIT_KEYS]),
            loadDomesticTraitModules([...DOMESTIC_TRAIT_KEYS]),
            loadWarTraitModules([...WAR_TRAIT_KEYS]),
            loadPersonalityTraitModules([...PERSONALITY_TRAIT_KEYS]),
        ]);
        const groups = { nation, domestic, war, personality };
        const failures: string[] = [];
        for (const [kind, modules] of Object.entries(groups) as Array<
            [keyof ReferenceTraitCatalog, Array<{ key: string; name: string; info: string }>]
        >) {
            expect(modules.map((module) => module.key).sort()).toEqual(Object.keys(reference[kind]).sort());
            for (const module of modules) {
                const actual = { name: module.name, info: module.info };
                if (JSON.stringify(actual) !== JSON.stringify(reference[kind][module.key])) {
                    failures.push(
                        `${kind}/${module.key}: core=${JSON.stringify(actual)} ref=${JSON.stringify(reference[kind][module.key])}`
                    );
                }
            }
        }
        expect(failures, failures.join('\n')).toEqual([]);
    });

    it('matches every war, personality, and nation trait in battle', { timeout: 180_000 }, () => {
        const unitSet = readJson<UnitSetDefinition>(
            path.resolve(process.cwd(), '../../resources/unitset/unitset_che.json')
        );
        const config: WarEngineConfig = {
            armPerPhase: 500,
            maxTrainByCommand: 100,
            maxAtmosByCommand: 100,
            maxTrainByWar: 110,
            maxAtmosByWar: 150,
            castleCrewTypeId: 1000,
            armTypes: { footman: 1, archer: 2, cavalry: 3, wizard: 4, siege: 5, misc: 6, castle: 0 },
        };
        const cases = [
            ...WAR_TRAIT_KEYS.map((key) => ({ kind: 'war' as const, key })),
            ...PERSONALITY_TRAIT_KEYS.map((key) => ({ kind: 'personality' as const, key })),
            ...NATION_TRAIT_KEYS.map((key) => ({ kind: 'nation' as const, key })),
        ];

        for (const entry of cases) {
            const base = readJson<BattleSimRequestPayload & { startYear: number }>(
                path.resolve(process.cwd(), 'fixtures/battle/basic-infantry.json')
            );
            base.seed = `battle-differential-trait-${entry.kind}-${entry.key}`;
            base.attackerGeneral.crew = 5000;
            base.attackerGeneral.leadership = 90;
            base.attackerGeneral.strength = 85;
            base.attackerGeneral.intel = 80;
            base.attackerGeneral.special2 = entry.kind === 'war' ? entry.key : 'None';
            base.attackerGeneral.personal = entry.kind === 'personality' ? entry.key : 'None';
            if (entry.kind === 'nation') {
                base.attackerNation.type = entry.key;
            }

            const coreEvents: WarBattleTraceEvent[] = [];
            let coreRng: TracingRng | null = null;
            processBattleSimJob(
                {
                    ...base,
                    unitSet,
                    config,
                    time: { year: base.year, month: base.month, startYear: base.startYear },
                },
                {
                    trace: (event) => coreEvents.push(event),
                    rngFactory: (seed) => {
                        coreRng = new TracingRng(LiteHashDRBG.build(seed));
                        return new RandUtil(coreRng);
                    },
                }
            );
            try {
                assertTraceParity(coreEvents, runReferenceTrace(workspaceRoot!, JSON.stringify(base)), coreRng);
            } catch (error) {
                throw new Error(`${entry.kind}/${entry.key}: ${error instanceof Error ? error.message : String(error)}`, {
                    cause: error,
                });
            }
        }
    });

    it('loads every scenario item with the scenario slot', async () => {
        const scenarioDir = path.resolve(process.cwd(), '../../resources/scenario');
        const itemSlots = new Map<string, 'horse' | 'weapon' | 'book' | 'item'>();
        for (const filename of fs.readdirSync(scenarioDir).filter((entry) => entry.endsWith('.json'))) {
            const scenario = readJson<{
                const?: {
                    allItems?: Partial<Record<'horse' | 'weapon' | 'book' | 'item', Record<string, number>>>;
                };
            }>(path.join(scenarioDir, filename));
            for (const slot of ['horse', 'weapon', 'book', 'item'] as const) {
                for (const itemKey of Object.keys(scenario.const?.allItems?.[slot] ?? {})) {
                    itemSlots.set(itemKey, slot);
                }
            }
        }

        const modules = await loadItemModules([...ITEM_KEYS]);
        const reference = runReferenceItemCatalog(workspaceRoot!, [...ITEM_KEYS]);
        expect(modules).toHaveLength(145);
        const failures: string[] = [];
        for (const module of modules) {
            const actual = {
                rawName: module.rawName,
                name: module.name,
                info: module.info,
                cost: module.cost,
                buyable: module.buyable,
                consumable: module.consumable,
                reqSecu: module.reqSecu,
            };
            if (
                module.slot !== itemSlots.get(module.key) ||
                module.unique !== !reference[module.key]?.buyable ||
                JSON.stringify(actual) !== JSON.stringify(reference[module.key])
            ) {
                failures.push(
                    `${module.key}: slot=${module.slot}/${String(itemSlots.get(module.key))} unique=${String(module.unique)}/${String(!reference[module.key]?.buyable)} core=${JSON.stringify(actual)} ref=${JSON.stringify(reference[module.key])}`
                );
            }
        }
        expect(failures, failures.join('\n')).toEqual([]);
    });

    it('matches the legacy non-stacking rule for the 무쌍 trait item', () => {
        const base = readJson<BattleSimRequestPayload & { startYear: number }>(
            path.resolve(process.cwd(), 'fixtures/battle/basic-infantry.json')
        );
        base.seed = 'battle-differential-duplicate-musang';
        base.attackerGeneral.personal = 'None';
        base.attackerGeneral.special2 = 'che_무쌍';
        base.attackerGeneral.item = 'event_전투특기_무쌍';
        base.attackerGeneral.crew = 5000;
        base.attackerGeneral.leadership = 90;
        base.attackerGeneral.strength = 90;
        base.attackerGeneral.intel = 90;
        base.attackerGeneral.dex1 = 12000;
        const unitSet = readJson<UnitSetDefinition>(
            path.resolve(process.cwd(), '../../resources/unitset/unitset_che.json')
        );
        const config: WarEngineConfig = {
            armPerPhase: 500,
            maxTrainByCommand: 100,
            maxAtmosByCommand: 100,
            maxTrainByWar: 110,
            maxAtmosByWar: 150,
            castleCrewTypeId: 1000,
            armTypes: { footman: 1, archer: 2, cavalry: 3, wizard: 4, siege: 5, misc: 6, castle: 0 },
        };
        const coreEvents: WarBattleTraceEvent[] = [];
        let coreRng: TracingRng | null = null;
        processBattleSimJob(
            {
                ...base,
                unitSet,
                config,
                time: { year: base.year, month: base.month, startYear: base.startYear },
            },
            {
                trace: (event) => coreEvents.push(event),
                rngFactory: (seed) => {
                    coreRng = new TracingRng(LiteHashDRBG.build(seed));
                    return new RandUtil(coreRng);
                },
            }
        );
        assertTraceParity(coreEvents, runReferenceTrace(workspaceRoot!, JSON.stringify(base)), coreRng);
    });

    it('matches 척사 items against region-restricted troops', () => {
        const unitSet = readJson<UnitSetDefinition>(
            path.resolve(process.cwd(), '../../resources/unitset/unitset_che.json')
        );
        const config: WarEngineConfig = {
            armPerPhase: 500,
            maxTrainByCommand: 100,
            maxAtmosByCommand: 100,
            maxTrainByWar: 110,
            maxAtmosByWar: 150,
            castleCrewTypeId: 1000,
            armTypes: { footman: 1, archer: 2, cavalry: 3, wizard: 4, siege: 5, misc: 6, castle: 0 },
        };

        for (const itemKey of ['che_척사_오악진형도', 'event_전투특기_척사']) {
            const base = readJson<BattleSimRequestPayload & { startYear: number }>(
                path.resolve(process.cwd(), 'fixtures/battle/basic-infantry.json')
            );
            base.seed = `battle-differential-region-item-${itemKey}`;
            base.attackerGeneral.personal = 'None';
            base.attackerGeneral.special2 = 'None';
            base.attackerGeneral.item = itemKey;
            base.attackerGeneral.crew = 5000;
            base.defenderGenerals[0]!.crewtype = 1101;
            const coreEvents: WarBattleTraceEvent[] = [];
            let coreRng: TracingRng | null = null;
            processBattleSimJob(
                {
                    ...base,
                    unitSet,
                    config,
                    time: { year: base.year, month: base.month, startYear: base.startYear },
                },
                {
                    trace: (event) => coreEvents.push(event),
                    rngFactory: (seed) => {
                        coreRng = new TracingRng(LiteHashDRBG.build(seed));
                        return new RandUtil(coreRng);
                    },
                }
            );
            assertTraceParity(coreEvents, runReferenceTrace(workspaceRoot!, JSON.stringify(base)), coreRng);
        }
    });

    it('keeps the detailed event sequence and phase values within 1%', () => {
        const fixturePath = path.resolve(process.cwd(), 'fixtures/battle/basic-infantry.json');
        const fixtureJson = fs.readFileSync(fixturePath, 'utf8');
        const request = JSON.parse(fixtureJson) as BattleSimRequestPayload & { startYear: number };
        const unitSet = readJson<UnitSetDefinition>(
            path.resolve(process.cwd(), '../../resources/unitset/unitset_che.json')
        );
        const castleCrewTypeId = 1000;
        const config: WarEngineConfig = {
            armPerPhase: 500,
            maxTrainByCommand: 100,
            maxAtmosByCommand: 100,
            maxTrainByWar: 110,
            maxAtmosByWar: 150,
            castleCrewTypeId,
            armTypes: {
                footman: 1,
                archer: 2,
                cavalry: 3,
                wizard: 4,
                siege: 5,
                misc: 6,
                castle: unitSet.crewTypes?.find((crewType) => crewType.id === castleCrewTypeId)?.armType ?? 0,
            },
        };
        const payload: BattleSimJobPayload = {
            ...request,
            unitSet,
            config,
            time: { year: request.year, month: request.month, startYear: request.startYear },
        };

        const coreEvents: WarBattleTraceEvent[] = [];
        let coreRng: TracingRng | null = null;
        const coreResult = processBattleSimJob(payload, {
            trace: (event) => coreEvents.push(event),
            rngFactory: (seed) => {
                coreRng = new TracingRng(LiteHashDRBG.build(seed));
                return new RandUtil(coreRng);
            },
        });
        const reference = runReferenceTrace(workspaceRoot!, fixtureJson);

        expect(coreResult.result).toBe(true);
        assertTraceParity(coreEvents, reference, coreRng);
    });

    it('matches wizard strategy attempts, outcomes, and RNG consumption', () => {
        const base = readJson<BattleSimRequestPayload & { startYear: number }>(
            path.resolve(process.cwd(), 'fixtures/battle/basic-infantry.json')
        );
        base.seed = 'battle-differential-magic-v1';
        base.attackerGeneral.crew = 4000;
        base.attackerGeneral.crewtype = 1400;
        base.attackerGeneral.leadership = 60;
        base.attackerGeneral.strength = 30;
        base.attackerGeneral.intel = 95;
        base.attackerGeneral.special2 = 'che_신산';
        base.attackerGeneral.personal = 'che_재간';
        base.attackerGeneral.dex4 = 12000;
        base.defenderGenerals[0]!.crew = 4000;
        base.defenderGenerals[0]!.crewtype = 1100;
        base.defenderGenerals[0]!.leadership = 65;
        base.defenderGenerals[0]!.strength = 75;
        base.defenderGenerals[0]!.intel = 35;
        base.defenderGenerals[0]!.special2 = 'che_견고';
        base.defenderGenerals[0]!.personal = 'che_유지';

        const fixtureJson = JSON.stringify(base);
        const unitSet = readJson<UnitSetDefinition>(
            path.resolve(process.cwd(), '../../resources/unitset/unitset_che.json')
        );
        const config: WarEngineConfig = {
            armPerPhase: 500,
            maxTrainByCommand: 100,
            maxAtmosByCommand: 100,
            maxTrainByWar: 110,
            maxAtmosByWar: 150,
            castleCrewTypeId: 1000,
            armTypes: { footman: 1, archer: 2, cavalry: 3, wizard: 4, siege: 5, misc: 6, castle: 0 },
        };
        const payload: BattleSimJobPayload = {
            ...base,
            unitSet,
            config,
            time: { year: base.year, month: base.month, startYear: base.startYear },
        };
        const coreEvents: WarBattleTraceEvent[] = [];
        let coreRng: TracingRng | null = null;
        const result = processBattleSimJob(payload, {
            trace: (event) => coreEvents.push(event),
            rngFactory: (seed) => {
                coreRng = new TracingRng(LiteHashDRBG.build(seed));
                return new RandUtil(coreRng);
            },
        });
        const reference = runReferenceTrace(workspaceRoot!, fixtureJson);

        expect(result.result).toBe(true);
        expect(
            reference.events.some((event) =>
                Object.keys(event.attacker.activatedSkills).some((skill) => ['계략', '계략실패'].includes(skill))
            )
        ).toBe(true);
        assertTraceParity(coreEvents, reference, coreRng);
    });

    it('matches cavalry, item, inherit-buff, and multiple-defender handling', () => {
        const base = readJson<BattleSimRequestPayload & { startYear: number }>(
            path.resolve(process.cwd(), 'fixtures/battle/basic-infantry.json')
        );
        base.seed = 'battle-differential-cavalry-items-v1';
        base.attackerGeneral.crew = 7000;
        base.attackerGeneral.crewtype = 1300;
        base.attackerGeneral.leadership = 88;
        base.attackerGeneral.strength = 92;
        base.attackerGeneral.intel = 55;
        base.attackerGeneral.special2 = 'che_기병';
        base.attackerGeneral.personal = 'che_패권';
        base.attackerGeneral.horse = 'che_명마_07_백상';
        base.attackerGeneral.dex3 = 18000;
        base.attackerGeneral.inheritBuff = {
            warAvoidRatio: 2,
            warCriticalRatio: 3,
            warCriticalRatioOppose: 2,
        };

        const firstDefender = base.defenderGenerals[0]!;
        firstDefender.crew = 900;
        firstDefender.crewtype = 1200;
        firstDefender.leadership = 58;
        firstDefender.strength = 55;
        firstDefender.intel = 62;
        firstDefender.dex2 = 6000;
        firstDefender.inheritBuff = { warAvoidRatioOppose: 2 };
        base.defenderGenerals.push({
            ...firstDefender,
            no: 3,
            name: '수비자2',
            crew: 1100,
            crewtype: 1300,
            leadership: 64,
            strength: 72,
            intel: 48,
            dex2: 0,
            dex3: 8000,
            special2: 'che_기병',
            personal: 'che_패권',
            horse: 'che_명마_07_백상',
            inheritBuff: {
                warAvoidRatio: 1,
                warCriticalRatioOppose: 1,
            },
        });

        const fixtureJson = JSON.stringify(base);
        const unitSet = readJson<UnitSetDefinition>(
            path.resolve(process.cwd(), '../../resources/unitset/unitset_che.json')
        );
        const config: WarEngineConfig = {
            armPerPhase: 500,
            maxTrainByCommand: 100,
            maxAtmosByCommand: 100,
            maxTrainByWar: 110,
            maxAtmosByWar: 150,
            castleCrewTypeId: 1000,
            armTypes: { footman: 1, archer: 2, cavalry: 3, wizard: 4, siege: 5, misc: 6, castle: 0 },
        };
        const payload: BattleSimJobPayload = {
            ...base,
            unitSet,
            config,
            time: { year: base.year, month: base.month, startYear: base.startYear },
        };
        const coreEvents: WarBattleTraceEvent[] = [];
        let coreRng: TracingRng | null = null;
        const result = processBattleSimJob(payload, {
            trace: (event) => coreEvents.push(event),
            rngFactory: (seed) => {
                coreRng = new TracingRng(LiteHashDRBG.build(seed));
                return new RandUtil(coreRng);
            },
        });
        const reference = runReferenceTrace(workspaceRoot!, fixtureJson);

        expect(result.result).toBe(true);
        expect(reference.events.filter((event) => event.event === 'opponent_switched')).toHaveLength(2);
        assertTraceParity(coreEvents, reference, coreRng);
    });

    it('matches siege dexterity and castle damage handling', () => {
        const base = readJson<BattleSimRequestPayload & { startYear: number }>(
            path.resolve(process.cwd(), 'fixtures/battle/basic-infantry.json')
        );
        base.seed = 'battle-differential-siege-v1';
        base.attackerGeneral.crew = 5000;
        base.attackerGeneral.crewtype = 1501;
        base.attackerGeneral.leadership = 90;
        base.attackerGeneral.strength = 65;
        base.attackerGeneral.intel = 55;
        base.attackerGeneral.dex5 = 16000;
        base.defenderGenerals[0]!.crew = 300;
        base.defenderGenerals[0]!.crewtype = 1200;
        base.defenderGenerals[0]!.leadership = 65;
        base.defenderGenerals[0]!.strength = 72;
        base.defenderGenerals[0]!.intel = 50;
        base.defenderGenerals[0]!.dex2 = 10000;

        const fixtureJson = JSON.stringify(base);
        const unitSet = readJson<UnitSetDefinition>(
            path.resolve(process.cwd(), '../../resources/unitset/unitset_che.json')
        );
        const config: WarEngineConfig = {
            armPerPhase: 500,
            maxTrainByCommand: 100,
            maxAtmosByCommand: 100,
            maxTrainByWar: 110,
            maxAtmosByWar: 150,
            castleCrewTypeId: 1000,
            armTypes: { footman: 1, archer: 2, cavalry: 3, wizard: 4, siege: 5, misc: 6, castle: 0 },
        };
        const payload: BattleSimJobPayload = {
            ...base,
            unitSet,
            config,
            time: { year: base.year, month: base.month, startYear: base.startYear },
        };
        const coreEvents: WarBattleTraceEvent[] = [];
        let coreRng: TracingRng | null = null;
        const result = processBattleSimJob(payload, {
            trace: (event) => coreEvents.push(event),
            rngFactory: (seed) => {
                coreRng = new TracingRng(LiteHashDRBG.build(seed));
                return new RandUtil(coreRng);
            },
        });
        const reference = runReferenceTrace(workspaceRoot!, fixtureJson);

        expect(result.result).toBe(true);
        expect(reference.events.some((event) => event.defender?.kind === 'city')).toBe(true);
        assertTraceParity(coreEvents, reference, coreRng);
    });

    it('matches the no-defender supply-retreat branch without consuming RNG', () => {
        const base = readJson<BattleSimRequestPayload & { startYear: number }>(
            path.resolve(process.cwd(), 'fixtures/battle/basic-infantry.json')
        );
        base.seed = 'battle-differential-supply-v1';
        base.defenderGenerals = [];
        base.defenderNation.rice = 0;

        const fixtureJson = JSON.stringify(base);
        const unitSet = readJson<UnitSetDefinition>(
            path.resolve(process.cwd(), '../../resources/unitset/unitset_che.json')
        );
        const config: WarEngineConfig = {
            armPerPhase: 500,
            maxTrainByCommand: 100,
            maxAtmosByCommand: 100,
            maxTrainByWar: 110,
            maxAtmosByWar: 150,
            castleCrewTypeId: 1000,
            armTypes: { footman: 1, archer: 2, cavalry: 3, wizard: 4, siege: 5, misc: 6, castle: 0 },
        };
        const payload: BattleSimJobPayload = {
            ...base,
            unitSet,
            config,
            time: { year: base.year, month: base.month, startYear: base.startYear },
        };
        const coreEvents: WarBattleTraceEvent[] = [];
        let coreRng: TracingRng | null = null;
        const result = processBattleSimJob(payload, {
            trace: (event) => coreEvents.push(event),
            rngFactory: (seed) => {
                coreRng = new TracingRng(LiteHashDRBG.build(seed));
                return new RandUtil(coreRng);
            },
        });
        const reference = runReferenceTrace(workspaceRoot!, fixtureJson);

        expect(result.result).toBe(true);
        expect(reference.events.map((event) => event.event)).toEqual(['battle_start', 'supply_retreat', 'battle_end']);
        assertTraceParity(coreEvents, reference, coreRng);
    });

    it('matches every scenario item in an attacker battle simulation', { timeout: 180_000 }, () => {
        const scenarioDir = path.resolve(process.cwd(), '../../resources/scenario');
        const itemSlots = new Map<string, 'horse' | 'weapon' | 'book' | 'item'>();
        for (const filename of fs.readdirSync(scenarioDir).filter((entry) => entry.endsWith('.json'))) {
            const scenario = readJson<{
                const?: {
                    allItems?: Partial<Record<'horse' | 'weapon' | 'book' | 'item', Record<string, number>>>;
                };
            }>(path.join(scenarioDir, filename));
            for (const slot of ['horse', 'weapon', 'book', 'item'] as const) {
                for (const itemKey of Object.keys(scenario.const?.allItems?.[slot] ?? {})) {
                    itemSlots.set(itemKey, slot);
                }
            }
        }
        expect(itemSlots.size).toBe(145);
        expect([...ITEM_KEYS].sort()).toEqual([...itemSlots.keys()].sort());

        const unitSet = readJson<UnitSetDefinition>(
            path.resolve(process.cwd(), '../../resources/unitset/unitset_che.json')
        );
        const config: WarEngineConfig = {
            armPerPhase: 500,
            maxTrainByCommand: 100,
            maxAtmosByCommand: 100,
            maxTrainByWar: 110,
            maxAtmosByWar: 150,
            castleCrewTypeId: 1000,
            armTypes: {
                footman: 1,
                archer: 2,
                cavalry: 3,
                wizard: 4,
                siege: 5,
                misc: 6,
                castle: 0,
            },
        };
        const failures: string[] = [];

        const itemFilter = process.env['ITEM_PARITY_FILTER'];
        for (const [itemKey, slot] of [...itemSlots].sort(([lhs], [rhs]) => lhs.localeCompare(rhs))) {
            if (itemFilter && itemKey !== itemFilter) {
                continue;
            }
            const base = readJson<BattleSimRequestPayload & { startYear: number }>(
                path.resolve(process.cwd(), 'fixtures/battle/basic-infantry.json')
            );
            base.seed = `battle-differential-item-${itemKey}`;
            base.attackerGeneral.personal = 'None';
            base.attackerGeneral.special2 = 'None';
            base.attackerGeneral.crew = 5000;
            base.attackerGeneral.leadership = 90;
            base.attackerGeneral.strength = 90;
            base.attackerGeneral.intel = 90;
            base.attackerGeneral.dex1 = 12000;
            base.attackerGeneral.dex2 = 12000;
            base.attackerGeneral.dex3 = 12000;
            base.attackerGeneral.dex4 = 12000;
            base.attackerGeneral.dex5 = 12000;
            base.attackerGeneral[slot] = itemKey;
            const defender = base.defenderGenerals[0]!;
            defender.personal = 'None';
            defender.special2 = 'None';
            defender.crew = 1500;
            defender.leadership = 75;
            defender.strength = 75;
            defender.intel = 75;
            base.defenderCity.wall = 3000;
            base.defenderCity.wall_max = 3000;

            const payload: BattleSimJobPayload = {
                ...base,
                unitSet,
                config,
                time: { year: base.year, month: base.month, startYear: base.startYear },
            };
            const coreEvents: WarBattleTraceEvent[] = [];
            let coreRng: TracingRng | null = null;
            processBattleSimJob(payload, {
                trace: (event) => coreEvents.push(event),
                rngFactory: (seed) => {
                    coreRng = new TracingRng(LiteHashDRBG.build(seed));
                    return new RandUtil(coreRng);
                },
            });
            const reference = runReferenceTrace(workspaceRoot!, JSON.stringify(base));
            try {
                assertTraceParity(coreEvents, reference, coreRng);
            } catch (error) {
                const debug =
                    process.env['ITEM_PARITY_DEBUG'] === '1'
                        ? `\ncore=${JSON.stringify(
                              coreEvents
                                      .map((event, index) => ({ index, event }))
                                      .filter(({ event }) => event.event === 'phase_power' || event.event === 'phase_damage')
                          )}\nref=${JSON.stringify(
                              reference.events
                                      .map((event, index) => ({ index, event }))
                                      .filter(({ event }) => event.event === 'phase_power' || event.event === 'phase_damage')
                          )}`
                        : '';
                failures.push(`${itemKey}: ${error instanceof Error ? error.message : String(error)}${debug}`);
            }
        }
        expect(failures, failures.join('\n')).toEqual([]);
    });

    it('matches every scenario item in a defender battle simulation', { timeout: 180_000 }, () => {
        const scenarioDir = path.resolve(process.cwd(), '../../resources/scenario');
        const itemSlots = new Map<string, 'horse' | 'weapon' | 'book' | 'item'>();
        for (const filename of fs.readdirSync(scenarioDir).filter((entry) => entry.endsWith('.json'))) {
            const scenario = readJson<{
                const?: {
                    allItems?: Partial<Record<'horse' | 'weapon' | 'book' | 'item', Record<string, number>>>;
                };
            }>(path.join(scenarioDir, filename));
            for (const slot of ['horse', 'weapon', 'book', 'item'] as const) {
                for (const itemKey of Object.keys(scenario.const?.allItems?.[slot] ?? {})) {
                    itemSlots.set(itemKey, slot);
                }
            }
        }

        const unitSet = readJson<UnitSetDefinition>(
            path.resolve(process.cwd(), '../../resources/unitset/unitset_che.json')
        );
        const config: WarEngineConfig = {
            armPerPhase: 500,
            maxTrainByCommand: 100,
            maxAtmosByCommand: 100,
            maxTrainByWar: 110,
            maxAtmosByWar: 150,
            castleCrewTypeId: 1000,
            armTypes: {
                footman: 1,
                archer: 2,
                cavalry: 3,
                wizard: 4,
                siege: 5,
                misc: 6,
                castle: 0,
            },
        };
        const failures: string[] = [];

        const itemFilter = process.env['ITEM_PARITY_FILTER'];
        for (const [itemKey, slot] of [...itemSlots].sort(([lhs], [rhs]) => lhs.localeCompare(rhs))) {
            if (itemFilter && itemKey !== itemFilter) {
                continue;
            }
            const base = readJson<BattleSimRequestPayload & { startYear: number }>(
                path.resolve(process.cwd(), 'fixtures/battle/basic-infantry.json')
            );
            base.seed = `battle-differential-defender-item-${itemKey}`;
            base.attackerGeneral.personal = 'None';
            base.attackerGeneral.special2 = 'None';
            base.attackerGeneral.crew = 1500;
            base.attackerGeneral.leadership = 75;
            base.attackerGeneral.strength = 75;
            base.attackerGeneral.intel = 75;
            const defender = base.defenderGenerals[0]!;
            defender.personal = 'None';
            defender.special2 = 'None';
            defender.crew = 5000;
            defender.leadership = 90;
            defender.strength = 90;
            defender.intel = 90;
            defender.dex1 = 12000;
            defender.dex2 = 12000;
            defender.dex3 = 12000;
            defender.dex4 = 12000;
            defender.dex5 = 12000;
            defender[slot] = itemKey;

            const payload: BattleSimJobPayload = {
                ...base,
                unitSet,
                config,
                time: { year: base.year, month: base.month, startYear: base.startYear },
            };
            const coreEvents: WarBattleTraceEvent[] = [];
            let coreRng: TracingRng | null = null;
            processBattleSimJob(payload, {
                trace: (event) => coreEvents.push(event),
                rngFactory: (seed) => {
                    coreRng = new TracingRng(LiteHashDRBG.build(seed));
                    return new RandUtil(coreRng);
                },
            });
            const reference = runReferenceTrace(workspaceRoot!, JSON.stringify(base));
            try {
                assertTraceParity(coreEvents, reference, coreRng);
            } catch (error) {
                const debug =
                    process.env['ITEM_PARITY_DEBUG'] === '1'
                        ? `\ncore=${JSON.stringify(
                              coreEvents
                                  .map((event, index) => ({ index, event }))
                                  .filter(({ event }) => event.event === 'phase_power' || event.event === 'phase_damage')
                          )}\nref=${JSON.stringify(
                              reference.events
                                  .map((event, index) => ({ index, event }))
                                  .filter(({ event }) => event.event === 'phase_power' || event.event === 'phase_damage')
                          )}`
                        : '';
                failures.push(`${itemKey}: ${error instanceof Error ? error.message : String(error)}${debug}`);
            }
        }
        expect(failures, failures.join('\n')).toEqual([]);
    });
});