/**
 * AgentEngine Tests — Chunked Writer Architecture
 *
 * 예전 buildup(planner → researcher → reflector → writer → synthesizer)을 단일
 * ChunkedWriter 의 outline → section[N] → polish 로 교체한 뒤의 회귀 테스트.
 *
 * 다루는 범위:
 *   1. ErrorClassifier  — TRANSIENT / PERMANENT / ABORT 분류 패턴
 *   2. ErrorRecoveryMatrix — 각 유형이 의도된 action·재시도 카운트로 매핑
 *   3. MissionState — audit trail / 상태 전환 / 구조화 로그
 *   4. AgentEngine.runMission — chunked 흐름(outline 1회 → section N회 → polish 1회)
 *   5. WikiFormatter gate — formatAsKnowledgeArtifact 옵션에 한해서만 wrap
 */

import {
    AgentEngine,
    IAgent,
    AgentExecuteOptions,
    ErrorClassifier,
    ErrorType,
    ERROR_RECOVERY_MATRIX,
    MissionState,
    PipelineStage,
} from '../src/lib/engine';
import * as fs from 'fs';
import * as path from 'path';

// ─── Setup ───────────────────────────────────────────────────────────────────

const getBaseDir = () => process.env.ASTRA_TEST_ROOT || process.cwd();

const clearCache = () => {
    const baseDir = getBaseDir();
    for (const sub of ['cache', 'missions']) {
        const dir = path.join(baseDir, '.astra', sub);
        if (fs.existsSync(dir)) fs.rmSync(dir, { recursive: true, force: true });
    }
};

beforeAll(() => {
    process.env.ASTRA_TEST_ROOT = path.join(process.cwd(), '.astra', 'tests', 'engine');
    if (!fs.existsSync(process.env.ASTRA_TEST_ROOT)) {
        fs.mkdirSync(process.env.ASTRA_TEST_ROOT, { recursive: true });
    }
    clearCache();
});

beforeEach(() => { clearCache(); });

// ─── Mock agents ─────────────────────────────────────────────────────────────

/**
 * Role-aware mock — ChunkedWriter 처럼 options.config.role 에 따라 다른 응답을
 * 돌려준다. 실제 작은 모델의 행동을 단순 시뮬레이션.
 */
class MockChunkedWriter implements IAgent {
    public calls: Array<{ role: string; input: string }> = [];
    constructor(
        private readonly outlineJson: string = '[{"heading":"본문","scope":"전체 답변을 다루는 단일 섹션"}]',
        private readonly sectionText: string = '본문 내용은 충분히 길게 작성된 mock 응답입니다.',
        private readonly polished: string = '최종 답변 본문 — 사용자에게 보일 polish 결과입니다. 충분히 긴 문자열.',
        private readonly direct: string = '직답 결과 — single-pass mock 응답입니다.',
    ) {}
    async execute(input: string, _ctx?: string, _signal?: AbortSignal, options?: AgentExecuteOptions): Promise<string> {
        const role = (options?.config?.role as string | undefined) ?? 'section';
        this.calls.push({ role, input });
        if (role === 'outline') return this.outlineJson;
        if (role === 'polish') return this.polished;
        if (role === 'direct') return this.direct;
        return this.sectionText;
    }
}

class MockPermanentAgent implements IAgent {
    async execute(): Promise<string> {
        throw new Error('404: model not found');
    }
}

class MockAbortAgent implements IAgent {
    async execute(): Promise<string> {
        const err = new Error('AbortError');
        err.name = 'AbortError';
        throw err;
    }
}

const noopProgress = (_stage: PipelineStage, _message: string) => {};
const createAbortSignal = (): AbortSignal => new AbortController().signal;

/**
 * Fast-path 휴리스틱을 통과해 chunked 흐름으로 가도록 충분히 긴 + 분석 키워드를
 * 포함한 prompt. 200자 미만 / 키워드 없음 / 본문 첨부 없음이면 fast-path 가 발동해
 * outline·section 단계가 모두 우회된다.
 */
const CHUNKED_PROMPT = `다음 보고서를 종합적으로 분석해서 핵심 요점을 정리하고, ` +
    `각 섹션의 강점과 약점을 평가하며, 향후 개선 방향을 제안해 주세요. ` +
    `프로젝트 전반의 기획 의도와 실제 구현 결과 사이의 정합성도 함께 검토해 주세요. ` +
    `리뷰는 가능한 한 상세하고 꼼꼼하게 작성되어야 합니다.`;

// ─── ErrorClassifier ─────────────────────────────────────────────────────────

describe('ErrorClassifier', () => {
    describe('Transient', () => {
        const messages = [
            'ECONNREFUSED: Connection refused',
            'Request timeout exceeded',
            'ETIMEDOUT: operation timed out',
            'ECONNRESET: connection reset by peer',
            'network error occurred',
            'Failed to fetch',
            'HTTP 503: Service Unavailable',
            'HTTP 502: Bad Gateway',
            'HTTP 429: Too Many Requests',
            'socket hang up',
        ];
        test.each(messages)('"%s" → TRANSIENT', (msg) => {
            const r = ErrorClassifier.classify(new Error(msg));
            expect(r.type).toBe(ErrorType.TRANSIENT);
            expect(r.rule.action).toBe('retry');
            expect(r.rule.maxRetries).toBe(3);
        });
    });

    describe('Permanent', () => {
        const messages = [
            'HTTP 401: Unauthorized',
            'HTTP 403: Forbidden',
            'HTTP 404: Not Found',
            'Planner 에이전트로부터 유효한 응답을 받지 못했습니다',
            'Ollama URL이 설정되지 않았습니다',
            'invalid model name specified',
            'model not found in registry',
        ];
        test.each(messages)('"%s" → PERMANENT', (msg) => {
            const r = ErrorClassifier.classify(new Error(msg));
            expect(r.type).toBe(ErrorType.PERMANENT);
            expect(r.rule.action).toBe('fail_with_message');
            expect(r.rule.maxRetries).toBe(0);
        });
    });

    describe('Abort', () => {
        test('name="AbortError" → ABORT', () => {
            const err = new Error('cancelled');
            err.name = 'AbortError';
            expect(ErrorClassifier.classify(err).type).toBe(ErrorType.ABORT);
        });
        test('message="AbortError" → ABORT', () => {
            expect(ErrorClassifier.classify(new Error('AbortError')).type).toBe(ErrorType.ABORT);
        });
    });

    test('unknown → PERMANENT (보수적 처리)', () => {
        const r = ErrorClassifier.classify(new Error('something completely unexpected'));
        expect(r.type).toBe(ErrorType.PERMANENT);
    });
});

// ─── ErrorRecoveryMatrix ─────────────────────────────────────────────────────

describe('ErrorRecoveryMatrix', () => {
    test('세 유형 모두 정의돼 있어야 한다', () => {
        const types = ERROR_RECOVERY_MATRIX.map(r => r.type);
        expect(types).toContain(ErrorType.TRANSIENT);
        expect(types).toContain(ErrorType.PERMANENT);
        expect(types).toContain(ErrorType.ABORT);
    });
    test('TRANSIENT 은 재시도 가능', () => {
        const r = ERROR_RECOVERY_MATRIX.find(x => x.type === ErrorType.TRANSIENT)!;
        expect(r.maxRetries).toBeGreaterThan(0);
        expect(r.action).toBe('retry');
    });
    test('PERMANENT 은 재시도 없이 즉시 실패', () => {
        const r = ERROR_RECOVERY_MATRIX.find(x => x.type === ErrorType.PERMANENT)!;
        expect(r.maxRetries).toBe(0);
        expect(r.action).toBe('fail_with_message');
    });
    test('ABORT 은 조용히 종료', () => {
        const r = ERROR_RECOVERY_MATRIX.find(x => x.type === ErrorType.ABORT)!;
        expect(r.action).toBe('abort');
    });
});

// ─── MissionState ────────────────────────────────────────────────────────────

describe('MissionState', () => {
    test('초기 상태는 idle', () => {
        const s = new MissionState('m1');
        expect(s.stage).toBe('idle');
        expect(s.auditTrail.length).toBe(0);
    });

    test('chunked 흐름 stage 전환이 audit trail 에 기록된다', () => {
        const s = new MissionState('m2');
        s.transition('outline', '구조 잡는 중');
        s.transition('section', '섹션 1');
        s.transition('section', '섹션 2');
        s.transition('polish', '다듬는 중');
        s.transition('completed', '완료');
        expect(s.stage).toBe('completed');
        expect(s.auditTrail.length).toBe(5);
        expect(s.auditTrail[0].from).toBe('idle');
        expect(s.auditTrail[0].to).toBe('outline');
        expect(s.auditTrail[3].to).toBe('polish');
    });

    test('toStructuredLog() 가 올바른 JSON 구조를 반환한다', () => {
        const s = new MissionState('m3');
        s.transition('outline', 'a');
        s.transition('completed', 'b');
        const log = s.toStructuredLog() as any;
        expect(log.missionId).toBe('m3');
        expect(log.status).toBe('completed');
        expect(log.transitions).toHaveLength(2);
        expect(log.transitions[0].to).toBe('outline');
    });

    test('getElapsedMs() 는 음수가 아니다', () => {
        const s = new MissionState('m4');
        expect(s.getElapsedMs()).toBeGreaterThanOrEqual(0);
    });
});

// ─── AgentEngine — chunked flow ──────────────────────────────────────────────

describe('AgentEngine — chunked flow', () => {
    test('outline 1개 섹션 → outline + 1 section + polish (총 3회 호출)', async () => {
        const writer = new MockChunkedWriter();
        const engine = new AgentEngine(writer);
        const result = await engine.runMission(
            'chunked_single', CHUNKED_PROMPT, 'ctx', createAbortSignal(), noopProgress,
        );
        expect(result).toContain('최종 답변 본문');
        const roles = writer.calls.map(c => c.role);
        expect(roles).toEqual(['outline', 'section', 'polish']);
    });

    test('outline N개 → outline + N section + polish (N=3 일 때 5회 호출)', async () => {
        const writer = new MockChunkedWriter(
            '[{"heading":"A","scope":"a"},{"heading":"B","scope":"b"},{"heading":"C","scope":"c"}]'
        );
        const engine = new AgentEngine(writer);
        await engine.runMission(
            'chunked_multi', CHUNKED_PROMPT, 'ctx', createAbortSignal(), noopProgress,
        );
        const roles = writer.calls.map(c => c.role);
        expect(roles[0]).toBe('outline');
        expect(roles[roles.length - 1]).toBe('polish');
        expect(roles.filter(r => r === 'section')).toHaveLength(3);
    });

    test('outline MAX_SECTIONS 초과 응답은 5개로 cap 된다', async () => {
        // 7개를 줘도 5개로 잘려야 함
        const writer = new MockChunkedWriter(
            JSON.stringify(
                Array.from({ length: 7 }, (_, i) => ({ heading: `H${i}`, scope: `s${i}` }))
            )
        );
        const engine = new AgentEngine(writer);
        await engine.runMission(
            'chunked_cap', CHUNKED_PROMPT, 'ctx', createAbortSignal(), noopProgress,
        );
        const sectionCount = writer.calls.filter(c => c.role === 'section').length;
        expect(sectionCount).toBe(AgentEngine.MAX_SECTIONS);
    });

    test('outline JSON 파싱 실패 시 단일 "본문" 섹션으로 폴백', async () => {
        const writer = new MockChunkedWriter('this is not json at all');
        const engine = new AgentEngine(writer);
        await engine.runMission(
            'chunked_fallback', CHUNKED_PROMPT, 'ctx', createAbortSignal(), noopProgress,
        );
        const sectionCount = writer.calls.filter(c => c.role === 'section').length;
        expect(sectionCount).toBe(1);
    });

    test('outline JSON 이 ```json ... ``` 펜스로 감싸져 있어도 파싱', async () => {
        const writer = new MockChunkedWriter(
            '```json\n[{"heading":"H1","scope":"s1"},{"heading":"H2","scope":"s2"}]\n```'
        );
        const engine = new AgentEngine(writer);
        await engine.runMission(
            'chunked_fenced', CHUNKED_PROMPT, 'ctx', createAbortSignal(), noopProgress,
        );
        const sectionCount = writer.calls.filter(c => c.role === 'section').length;
        expect(sectionCount).toBe(2);
    });

    test('Permanent 오류는 즉시 중단', async () => {
        const engine = new AgentEngine(new MockPermanentAgent());
        await expect(
            engine.runMission('chunked_permanent', 'p', 'c', createAbortSignal(), noopProgress)
        ).rejects.toThrow();
    });

    test('Abort 시그널은 graceful exit', async () => {
        const engine = new AgentEngine(new MockAbortAgent());
        await expect(
            engine.runMission('chunked_abort', 'p', 'c', createAbortSignal(), noopProgress)
        ).rejects.toThrow('AbortError');
    });

    test('미션 완료 후 getMissionState() 는 null', async () => {
        const engine = new AgentEngine(new MockChunkedWriter());
        await engine.runMission(
            'chunked_state_cleanup', 'p', 'c', createAbortSignal(), noopProgress,
        );
        expect(engine.getMissionState()).toBeNull();
    });
});

// ─── AgentEngine — single-pass routing ──────────────────────────────────────

describe('AgentEngine — single-pass routing', () => {
    test('isObviouslySimple: 짧은 일반 질문 → true', () => {
        expect(AgentEngine.isObviouslySimple('오늘 날씨 어때?')).toBe(true);
        expect(AgentEngine.isObviouslySimple('이 함수 이름 뭐로 짓는 게 좋을까?')).toBe(true);
        expect(AgentEngine.isObviouslySimple('hello world')).toBe(true);
    });

    test('isObviouslySimple: 분석/리서치 키워드 포함 → false', () => {
        expect(AgentEngine.isObviouslySimple('이거 분석해줘')).toBe(false);
        expect(AgentEngine.isObviouslySimple('보고서 작성 부탁')).toBe(false);
        expect(AgentEngine.isObviouslySimple('아키텍처 설계 좀')).toBe(false);
    });

    test('isObviouslySimple: 본문 첨부 흔적 (코드 펜스 / 빈줄 다수) → false', () => {
        expect(AgentEngine.isObviouslySimple('```python\nprint(1)\n```')).toBe(false);
        expect(AgentEngine.isObviouslySimple('첫 줄\n\n\n둘째 줄')).toBe(false);
    });

    test('isObviouslySimple: 길이 200자 이상 → false', () => {
        const long = '가나다라마바사아자차카타파하'.repeat(20);
        expect(AgentEngine.isObviouslySimple(long)).toBe(false);
    });

    test('fast-path: 짧은 단순 질문은 outline·section 없이 direct 한 번만 호출', async () => {
        const writer = new MockChunkedWriter();
        const engine = new AgentEngine(writer);
        const result = await engine.runMission(
            'fastpath_simple', '이 함수 이름 뭐로 할까?', 'ctx', createAbortSignal(), noopProgress,
        );
        const roles = writer.calls.map(c => c.role);
        expect(roles).toEqual(['direct']);
        expect(result).toContain('직답 결과');
    });

    test('outline 빈배열 폴백: outline + direct 두 호출 (section·polish 건너뜀)', async () => {
        // outline 이 빈 배열로 "쪼갤 필요 없음" 신호 → direct 로 폴백.
        const writer = new MockChunkedWriter('[]');
        const engine = new AgentEngine(writer);
        await engine.runMission(
            'outline_empty', CHUNKED_PROMPT, 'ctx', createAbortSignal(), noopProgress,
        );
        const roles = writer.calls.map(c => c.role);
        expect(roles).toEqual(['outline', 'direct']);
    });

    test('direct stage 가 audit trail 에 기록된다', async () => {
        const writer = new MockChunkedWriter();
        const engine = new AgentEngine(writer);
        const stages: PipelineStage[] = [];
        await engine.runMission(
            'fastpath_audit', '뭐가 좋아?', 'ctx', createAbortSignal(),
            (stage) => { stages.push(stage); },
        );
        expect(stages).toContain('direct');
        expect(stages).not.toContain('outline');
        expect(stages).not.toContain('section');
    });
});

// ─── WikiFormatter gate ──────────────────────────────────────────────────────

describe('WikiFormatter gate', () => {
    test('기본은 wiki 포맷을 *적용하지 않는다*', async () => {
        const writer = new MockChunkedWriter();
        const engine = new AgentEngine(writer);
        const result = await engine.runMission(
            'wiki_off', 'p', 'c', createAbortSignal(), noopProgress,
        );
        expect(result).not.toContain('P-Reinforce v3.0');
        expect(result).not.toContain('Reliability & Audit Summary');
    });

    test('options.config.formatAsKnowledgeArtifact=true 일 때만 wrap', async () => {
        const writer = new MockChunkedWriter();
        const engine = new AgentEngine(writer);
        const result = await engine.runMission(
            'wiki_on', 'p', 'c', createAbortSignal(), noopProgress,
            { config: { formatAsKnowledgeArtifact: true } },
        );
        expect(result).toContain('P-Reinforce v3.0');
        expect(result).toContain('Reliability & Audit Summary');
    });
});