import { describe, it } from "@suaveplan/testing/runner";
import * as fc from "fast-check";
import { MemoryAuditAdapter } from "../src/adapters/memory/memory.js";
import { AuditEventType, AuditSeverity } from "../src/constants/index.js";
import { AuditLogger } from "../src/core/audit-logger/audit-logger.js";
import {
    computeEventHash,
    verifyChain,
} from "../src/core/chain-integrity/chain-integrity.js";
import type { AuditEvent } from "../src/types/audit-logging.types.js";

const eventBaseArb = fc.record({
    id: fc.uuid(),
    type: fc.constantFrom(...Object.values(AuditEventType)),
    severity: fc.constantFrom(...Object.values(AuditSeverity)),
    actor: fc.record({
        userId: fc.option(fc.uuid(), { nil: undefined }),
        sessionId: fc.option(fc.uuid(), { nil: undefined }),
    }),
    timestamp: fc.date({
        min: new Date("2020-01-01"),
        max: new Date("2030-01-01"),
    }),
});

describe("property: HMAC stability", () => {
    it("same inputs produce same hash", { timeout: 30000 }, () => {
        fc.assert(
            fc.property(
                eventBaseArb,
                fc.string({ minLength: 1 }),
                (event, secret) => {
                    const h1 = computeEventHash(event, secret);
                    const h2 = computeEventHash(event, secret);
                    return h1 === h2;
                }
            ),
            { numRuns: 50 }
        );
    });

    it("different secrets produce different hashes", { timeout: 30000 }, () => {
        fc.assert(
            fc.property(
                eventBaseArb,
                fc.string({ minLength: 1 }),
                fc.string({ minLength: 1 }),
                (event, s1, s2) => {
                    fc.pre(s1 !== s2);
                    return (
                        computeEventHash(event, s1) !==
                        computeEventHash(event, s2)
                    );
                }
            ),
            { numRuns: 50 }
        );
    });

    it("different events produce different hashes (same secret)", {
        timeout: 30000,
    }, () => {
        fc.assert(
            fc.property(
                eventBaseArb,
                eventBaseArb,
                fc.string({ minLength: 1 }),
                (e1, e2, secret) => {
                    // Only guarantee different hashes when key fields differ
                    fc.pre(e1.id !== e2.id);
                    return (
                        computeEventHash(e1, secret) !==
                        computeEventHash(e2, secret)
                    );
                }
            ),
            { numRuns: 50 }
        );
    });
});

describe("property: chain integrity mutation detection", () => {
    it("single mutation breaks chain at mutation index", {
        timeout: 30000,
    }, async () => {
        await fc.assert(
            fc.asyncProperty(
                fc.array(eventBaseArb, { minLength: 2, maxLength: 5 }),
                fc.string({ minLength: 1 }),
                async (bases, secret) => {
                    // Build a valid chain
                    const events: AuditEvent[] = [];
                    let previousHash: string | undefined;
                    for (const base of bases) {
                        const hash = computeEventHash(
                            base,
                            secret,
                            previousHash
                        );
                        const event: AuditEvent = {
                            ...base,
                            hash,
                            ...(previousHash !== undefined
                                ? { previousHash }
                                : {}),
                        };
                        events.push(event);
                        previousHash = hash;
                    }

                    const validResult = verifyChain(events, secret);
                    if (!validResult.valid) return false;

                    // Tamper with a random event (change userId)
                    const tamperIdx = 0;
                    const tampered = [...events];
                    tampered[tamperIdx] = {
                        ...events[tamperIdx]!,
                        actor: { userId: "tampered-user" },
                    };

                    const brokenResult = verifyChain(tampered, secret);
                    return (
                        !brokenResult.valid &&
                        brokenResult.brokenAt === tamperIdx
                    );
                }
            ),
            { numRuns: 30 }
        );
    });
});

describe("property: query filter correctness", () => {
    it("userId filter returns only matching events", {
        timeout: 30000,
    }, async () => {
        await fc.assert(
            fc.asyncProperty(
                fc.array(fc.uuid(), { minLength: 1, maxLength: 3 }),
                async (userIds) => {
                    const adapter = new MemoryAuditAdapter();
                    const logger = new AuditLogger({
                        storage: adapter,
                        secretKey: "s",
                    });

                    for (const userId of userIds) {
                        await logger.log({
                            type: AuditEventType.AUTH_LOGIN,
                            severity: AuditSeverity.INFO,
                            actor: { userId },
                        });
                    }

                    for (const userId of userIds) {
                        const results = await logger.query({ userId });
                        return results.every((e) => e.actor.userId === userId);
                    }
                    return true;
                }
            ),
            { numRuns: 20 }
        );
    });

    it("limit never exceeds requested count", { timeout: 30000 }, async () => {
        await fc.assert(
            fc.asyncProperty(
                fc.integer({ min: 1, max: 10 }),
                fc.integer({ min: 0, max: 5 }),
                async (total, limit) => {
                    const adapter = new MemoryAuditAdapter();
                    const logger = new AuditLogger({
                        storage: adapter,
                        secretKey: "s",
                    });

                    for (let i = 0; i < total; i++) {
                        await logger.log({
                            type: AuditEventType.AUTH_LOGIN,
                            severity: AuditSeverity.INFO,
                            actor: { userId: `u-${i}` },
                        });
                    }

                    const results = await logger.query({ limit });
                    return results.length <= limit;
                }
            ),
            { numRuns: 20 }
        );
    });
});