/**
 * Property-based tests using fast-check.
 */

import { describe, expect, it } from "@suaveplan/testing/runner";
import * as fc from "fast-check";
import { IdempotencyGuard } from "../src/guard/idempotency-guard.js";
import {
    compositeKey,
    fingerprintPayload,
    generateIdempotencyKey,
} from "../src/key/key-generator.js";
import { MemoryIdempotencyStore } from "../src/store/memory-store.js";
import { KeyVersioning } from "../src/versioning/key-versioning.js";

describe("Property: compositeKey", () => {
    it("is deterministic for equal inputs", { timeout: 30000 }, () => {
        fc.assert(
            fc.property(
                fc.array(fc.string({ minLength: 1 }), {
                    minLength: 1,
                    maxLength: 5,
                }),
                (parts) => {
                    const k1 = compositeKey(...parts);
                    const k2 = compositeKey(...parts);
                    expect(k1).toBe(k2);
                }
            ),
            { numRuns: 200 }
        );
    });

    it("produces a hex string for any non-empty input", {
        timeout: 30000,
    }, () => {
        fc.assert(
            fc.property(
                fc.array(fc.string({ minLength: 1 }), {
                    minLength: 1,
                    maxLength: 4,
                }),
                (parts) => {
                    const k = compositeKey(...parts);
                    expect(k).toMatch(/^[0-9a-f]+$/);
                }
            ),
            { numRuns: 200 }
        );
    });
});

describe("Property: fingerprintPayload", () => {
    it("produces same hash for JSON-equivalent objects (key-order independent)", {
        timeout: 30000,
    }, () => {
        fc.assert(
            fc.property(
                fc.dictionary(
                    fc.string({ minLength: 1, maxLength: 10 }),
                    fc.oneof(fc.integer(), fc.string(), fc.boolean())
                ),
                (obj) => {
                    // Reconstruct with reversed key order
                    const reversed = Object.fromEntries(
                        Object.entries(obj).reverse()
                    );
                    const fp1 = fingerprintPayload(obj);
                    const fp2 = fingerprintPayload(reversed);
                    expect(fp1).toBe(fp2);
                }
            ),
            { numRuns: 200 }
        );
    });

    it("produces different hashes for different values", {
        timeout: 30000,
    }, () => {
        // Not 100% true for collisions but holds for random non-equal primitives
        fc.assert(
            fc.property(
                fc.integer({ min: 0, max: 1_000_000 }),
                fc.integer({ min: 1_000_001, max: 2_000_000 }),
                (a, b) => {
                    expect(fingerprintPayload(a)).not.toBe(
                        fingerprintPayload(b)
                    );
                }
            ),
            { numRuns: 100 }
        );
    });
});

describe("Property: generateIdempotencyKey", () => {
    it("produces non-empty strings", { timeout: 30000 }, () => {
        fc.assert(
            fc.property(fc.constant(undefined), () => {
                const k = generateIdempotencyKey();
                expect(k.length).toBeGreaterThan(0);
            }),
            { numRuns: 100 }
        );
    });
});

describe("Property: IdempotencyGuard never executes fn twice for completed key", {
    timeout: 30000,
}, () => {
    it("fn called at most once across N concurrent calls", async () => {
        await fc.assert(
            fc.asyncProperty(
                fc.integer({ min: 2, max: 10 }),
                async (concurrency) => {
                    const store = new MemoryIdempotencyStore();
                    const guard = new IdempotencyGuard({ store });
                    let execCount = 0;
                    const fn = async () => {
                        execCount++;
                        return "result";
                    };
                    // Sequential calls (concurrency not fully simulated in single-thread)
                    for (let i = 0; i < concurrency; i++) {
                        await guard.execute("prop-key", fn);
                    }
                    expect(execCount).toBe(1);
                }
            ),
            { numRuns: 20 }
        );
    });
});

describe("Property: KeyVersioning never exceeds maxVersions", {
    timeout: 30000,
}, () => {
    it("history length stays within maxVersions", () => {
        fc.assert(
            fc.property(
                fc.integer({ min: 1, max: 20 }),
                fc.integer({ min: 1, max: 50 }),
                (maxVersions, insertCount) => {
                    const store = new MemoryIdempotencyStore();
                    const versioning = new KeyVersioning({
                        store,
                        maxVersions,
                    });
                    for (let i = 0; i < insertCount; i++) {
                        versioning.addVersionEntry("k", {
                            version: i + 1,
                            fingerprint: `fp${i}`,
                            status: "completed",
                            createdAt: Date.now(),
                        });
                    }
                    const history = versioning.getHistory("k");
                    expect(history.length).toBeLessThanOrEqual(maxVersions);
                }
            ),
            { numRuns: 100 }
        );
    });
});