import { beforeEach, describe, expect, it, vi } from "vitest";
import type { NDKEvent } from "@nostr-dev-kit/ndk";
import {
  deduplicateAndCombineEvents,
  deduplicateContentEvents,
  getEventCoordinate,
  isReplaceableEvent,
} from "../../src/lib/utils/eventDeduplication";

// Mock NDKEvent for testing
class MockNDKEvent {
  id: string;
  kind: number;
  pubkey: string;
  created_at: number;
  content: string;
  tags: string[][];

  constructor(
    id: string,
    kind: number,
    pubkey: string,
    created_at: number,
    dTag: string,
    content: string = "",
  ) {
    this.id = id;
    this.kind = kind;
    this.pubkey = pubkey;
    this.created_at = created_at;
    this.content = content;
    this.tags = [["d", dTag]];
  }

  tagValue(tagName: string): string | undefined {
    const tag = this.tags.find((t) => t[0] === tagName);
    return tag ? tag[1] : undefined;
  }
}

describe("Relay Deduplication Behavior Tests", () => {
  let mockEvents: MockNDKEvent[];

  beforeEach(() => {
    // Create test events with different timestamps
    mockEvents = [
      // Older version of a publication content event
      new MockNDKEvent(
        "event1",
        30041,
        "pubkey1",
        1000,
        "chapter-1",
        "Old content",
      ),
      // Newer version of the same publication content event
      new MockNDKEvent(
        "event2",
        30041,
        "pubkey1",
        2000,
        "chapter-1",
        "Updated content",
      ),
      // Different publication content event
      new MockNDKEvent(
        "event3",
        30041,
        "pubkey1",
        1500,
        "chapter-2",
        "Different content",
      ),
      // Publication index event (should not be deduplicated)
      new MockNDKEvent(
        "event4",
        30040,
        "pubkey1",
        1200,
        "book-1",
        "Index content",
      ),
      // Regular text note (should not be deduplicated)
      new MockNDKEvent("event5", 1, "pubkey1", 1300, "", "Regular note"),
    ];
  });

  describe("Addressable Event Deduplication", () => {
    it("should keep only the most recent version of addressable events by coordinate", () => {
      // Test the deduplication logic for content events
      const eventSets = [
        new Set(mockEvents.filter((e) => e.kind === 30041) as NDKEvent[]),
      ];
      const result = deduplicateContentEvents(eventSets);

      // Should have 2 unique coordinates: chapter-1 and chapter-2
      expect(result.size).toBe(2);

      // Should keep the newer version of chapter-1
      const chapter1Event = result.get("30041:pubkey1:chapter-1");
      expect(chapter1Event?.id).toBe("event2");
      expect(chapter1Event?.content).toBe("Updated content");

      // Should keep chapter-2
      const chapter2Event = result.get("30041:pubkey1:chapter-2");
      expect(chapter2Event?.id).toBe("event3");
    });

    it("should handle events with missing d-tags gracefully", () => {
      const eventWithoutDTag = new MockNDKEvent(
        "event6",
        30041,
        "pubkey1",
        1400,
        "",
        "No d-tag",
      );
      eventWithoutDTag.tags = []; // Remove d-tag

      const eventSets = [new Set([eventWithoutDTag] as NDKEvent[])];
      const result = deduplicateContentEvents(eventSets);

      // Should not include events without d-tags
      expect(result.size).toBe(0);
    });

    it("should handle events with missing timestamps", () => {
      const eventWithoutTimestamp = new MockNDKEvent(
        "event7",
        30041,
        "pubkey1",
        0,
        "chapter-3",
        "No timestamp",
      );
      const eventWithTimestamp = new MockNDKEvent(
        "event8",
        30041,
        "pubkey1",
        1500,
        "chapter-3",
        "With timestamp",
      );

      const eventSets = [
        new Set([eventWithoutTimestamp, eventWithTimestamp] as NDKEvent[]),
      ];
      const result = deduplicateContentEvents(eventSets);

      // Should prefer the event with timestamp
      const chapter3Event = result.get("30041:pubkey1:chapter-3");
      expect(chapter3Event?.id).toBe("event8");
    });
  });

  describe("Mixed Event Type Deduplication", () => {
    it("should only deduplicate addressable events (kinds 30000-39999)", () => {
      const result = deduplicateAndCombineEvents(
        [mockEvents[4]] as NDKEvent[], // Regular text note
        new Set([mockEvents[3]] as NDKEvent[]), // Publication index
        new Set([mockEvents[0], mockEvents[1], mockEvents[2]] as NDKEvent[]), // Content events
      );

      // Should have 4 events total:
      // - 1 regular text note (not deduplicated)
      // - 1 publication index (not deduplicated)
      // - 2 unique content events (deduplicated from 3)
      expect(result.length).toBe(4);

      // Verify the content events were deduplicated
      const contentEvents = result.filter((e) => e.kind === 30041);
      expect(contentEvents.length).toBe(2);

      // Verify the newer version was kept
      const newerEvent = contentEvents.find((e) => e.id === "event2");
      expect(newerEvent).toBeDefined();
    });

    it("should handle non-addressable events correctly", () => {
      const regularEvents = [
        new MockNDKEvent("note1", 1, "pubkey1", 1000, "", "Note 1"),
        new MockNDKEvent("note2", 1, "pubkey1", 2000, "", "Note 2"),
        new MockNDKEvent("profile1", 0, "pubkey1", 1500, "", "Profile 1"),
      ];

      const result = deduplicateAndCombineEvents(
        regularEvents as NDKEvent[],
        new Set(),
        new Set(),
      );

      // All regular events should be included (no deduplication)
      expect(result.length).toBe(3);
    });
  });

  describe("Coordinate System Validation", () => {
    it("should correctly identify event coordinates", () => {
      const event = new MockNDKEvent(
        "test",
        30041,
        "pubkey123",
        1000,
        "test-chapter",
      );
      const coordinate = getEventCoordinate(event as NDKEvent);

      expect(coordinate).toBe("30041:pubkey123:test-chapter");
    });

    it("should handle d-tags with colons correctly", () => {
      const event = new MockNDKEvent(
        "test",
        30041,
        "pubkey123",
        1000,
        "chapter:with:colons",
      );
      const coordinate = getEventCoordinate(event as NDKEvent);

      expect(coordinate).toBe("30041:pubkey123:chapter:with:colons");
    });

    it("should return null for non-replaceable events", () => {
      const event = new MockNDKEvent("test", 1, "pubkey123", 1000, "");
      const coordinate = getEventCoordinate(event as NDKEvent);

      expect(coordinate).toBeNull();
    });
  });

  describe("Replaceable Event Detection", () => {
    it("should correctly identify replaceable events", () => {
      const addressableEvent = new MockNDKEvent(
        "test",
        30041,
        "pubkey123",
        1000,
        "test",
      );
      const regularEvent = new MockNDKEvent("test", 1, "pubkey123", 1000, "");

      expect(isReplaceableEvent(addressableEvent as NDKEvent)).toBe(true);
      expect(isReplaceableEvent(regularEvent as NDKEvent)).toBe(false);
    });

    it("should handle edge cases of replaceable event ranges", () => {
      const event29999 = new MockNDKEvent(
        "test",
        29999,
        "pubkey123",
        1000,
        "test",
      );
      const event30000 = new MockNDKEvent(
        "test",
        30000,
        "pubkey123",
        1000,
        "test",
      );
      const event39999 = new MockNDKEvent(
        "test",
        39999,
        "pubkey123",
        1000,
        "test",
      );
      const event40000 = new MockNDKEvent(
        "test",
        40000,
        "pubkey123",
        1000,
        "test",
      );

      expect(isReplaceableEvent(event29999 as NDKEvent)).toBe(false);
      expect(isReplaceableEvent(event30000 as NDKEvent)).toBe(true);
      expect(isReplaceableEvent(event39999 as NDKEvent)).toBe(true);
      expect(isReplaceableEvent(event40000 as NDKEvent)).toBe(false);
    });
  });

  describe("Edge Cases", () => {
    it("should handle empty event sets", () => {
      const result = deduplicateContentEvents([]);
      expect(result.size).toBe(0);
    });

    it("should handle events with null/undefined values", () => {
      const invalidEvent = {
        id: undefined,
        kind: 30041,
        pubkey: "pubkey1",
        created_at: 1000,
        tagValue: () => undefined, // Return undefined for d-tag
      } as unknown as NDKEvent;

      const eventSets = [new Set([invalidEvent])];
      const result = deduplicateContentEvents(eventSets);

      // Should handle gracefully without crashing
      expect(result.size).toBe(0);
    });

    it("should handle events from different authors with same d-tag", () => {
      const event1 = new MockNDKEvent(
        "event1",
        30041,
        "pubkey1",
        1000,
        "same-chapter",
        "Author 1",
      );
      const event2 = new MockNDKEvent(
        "event2",
        30041,
        "pubkey2",
        1000,
        "same-chapter",
        "Author 2",
      );

      const eventSets = [new Set([event1, event2] as NDKEvent[])];
      const result = deduplicateContentEvents(eventSets);

      // Should have 2 events (different coordinates due to different authors)
      expect(result.size).toBe(2);
      expect(result.has("30041:pubkey1:same-chapter")).toBe(true);
      expect(result.has("30041:pubkey2:same-chapter")).toBe(true);
    });
  });
});

describe("Relay Behavior Simulation", () => {
  it("should simulate what happens when relays return duplicate events", () => {
    // Simulate a relay that returns multiple versions of the same event
    const relayEvents = [
      new MockNDKEvent(
        "event1",
        30041,
        "pubkey1",
        1000,
        "chapter-1",
        "Old version",
      ),
      new MockNDKEvent(
        "event2",
        30041,
        "pubkey1",
        2000,
        "chapter-1",
        "New version",
      ),
      new MockNDKEvent(
        "event3",
        30041,
        "pubkey1",
        1500,
        "chapter-1",
        "Middle version",
      ),
    ];

    // This simulates what a "bad" relay might return
    const eventSets = [new Set(relayEvents as NDKEvent[])];
    const result = deduplicateContentEvents(eventSets);

    // Should only keep the newest version
    expect(result.size).toBe(1);
    const keptEvent = result.get("30041:pubkey1:chapter-1");
    expect(keptEvent?.id).toBe("event2");
    expect(keptEvent?.content).toBe("New version");
  });

  it("should simulate multiple relays returning different versions", () => {
    // Simulate multiple relays returning different versions
    const relay1Events = [
      new MockNDKEvent(
        "event1",
        30041,
        "pubkey1",
        1000,
        "chapter-1",
        "Relay 1 version",
      ),
    ];

    const relay2Events = [
      new MockNDKEvent(
        "event2",
        30041,
        "pubkey1",
        2000,
        "chapter-1",
        "Relay 2 version",
      ),
    ];

    const eventSets = [
      new Set(relay1Events as NDKEvent[]),
      new Set(relay2Events as NDKEvent[]),
    ];
    const result = deduplicateContentEvents(eventSets);

    // Should keep the newest version from any relay
    expect(result.size).toBe(1);
    const keptEvent = result.get("30041:pubkey1:chapter-1");
    expect(keptEvent?.id).toBe("event2");
    expect(keptEvent?.content).toBe("Relay 2 version");
  });
});

describe("Real Relay Deduplication Tests", () => {
  // These tests actually query real relays to see if they deduplicate
  // Note: These are integration tests and may be flaky due to network conditions

  it(
    "should detect if relays are returning duplicate replaceable events",
    async () => {
      // This test queries real relays to see if they return duplicates
      // We'll use a known author who has published multiple versions of content

      // Known author with multiple publication content events
      const testAuthor =
        "npub1z4m7gkva6yxgvdyclc7zp0qt69x9zgn8lu8sllg06wx6432h77qs0k97ks";

      // Query for publication content events (kind 30041) from this author
      // We expect relays to return only the most recent version of each d-tag

      // This is a placeholder - in a real test, we would:
      // 1. Query multiple relays for the same author's 30041 events
      // 2. Check if any relay returns multiple events with the same d-tag
      // 3. Verify that if duplicates exist, our deduplication logic handles them

      console.log(
        "Note: This test would require actual relay queries to verify deduplication behavior",
      );
      console.log("To run this test properly, we would need to:");
      console.log("1. Query real relays for replaceable events");
      console.log("2. Check if relays return duplicates");
      console.log("3. Verify our deduplication logic works on real data");

      // For now, we'll just assert that our logic is ready to handle real data
      expect(true).toBe(true);
    },
    30000,
  ); // 30 second timeout for network requests

  it(
    "should verify that our deduplication logic works on real relay data",
    async () => {
      // This test would:
      // 1. Fetch real events from relays
      // 2. Apply our deduplication logic
      // 3. Verify that the results are correct

      console.log("Note: This test would require actual relay queries");
      console.log("To implement this test, we would need to:");
      console.log("1. Set up NDK with real relays");
      console.log("2. Fetch events for a known author with multiple versions");
      console.log("3. Apply deduplication and verify results");

      expect(true).toBe(true);
    },
    30000,
  );
});

describe("Practical Relay Behavior Analysis", () => {
  it("should document what we know about relay deduplication behavior", () => {
    // This test documents our current understanding of relay behavior
    // based on the code analysis and the comment from onedev

    console.log("\n=== RELAY DEDUPLICATION BEHAVIOR ANALYSIS ===");
    console.log("\nBased on the code analysis and the comment from onedev:");
    console.log("\n1. THEORETICAL BEHAVIOR:");
    console.log(
      "   - Relays SHOULD handle deduplication for replaceable events",
    );
    console.log(
      "   - Only the most recent version of each coordinate should be stored",
    );
    console.log(
      "   - Client-side deduplication should only be needed for cached/local events",
    );

    console.log("\n2. REALITY CHECK:");
    console.log("   - Not all relays implement deduplication correctly");
    console.log(
      "   - Some relays may return multiple versions of the same event",
    );
    console.log(
      "   - Network conditions and relay availability can cause inconsistencies",
    );

    console.log("\n3. ALEXANDRIA'S APPROACH:");
    console.log("   - Implements client-side deduplication as a safety net");
    console.log(
      "   - Uses coordinate system (kind:pubkey:d-tag) for addressable events",
    );
    console.log(
      "   - Keeps the most recent version based on created_at timestamp",
    );
    console.log("   - Only applies to replaceable events (kinds 30000-39999)");

    console.log("\n4. WHY KEEP THE DEDUPLICATION:");
    console.log(
      "   - Defensive programming against imperfect relay implementations",
    );
    console.log("   - Handles multiple relay sources with different data");
    console.log("   - Works with cached events that might be outdated");
    console.log(
      "   - Ensures consistent user experience regardless of relay behavior",
    );

    console.log("\n5. TESTING STRATEGY:");
    console.log(
      "   - Unit tests verify our deduplication logic works correctly",
    );
    console.log(
      "   - Integration tests would verify relay behavior (when network allows)",
    );
    console.log(
      "   - Monitoring can help determine if relays improve over time",
    );

    // This test documents our understanding rather than asserting specific behavior
    expect(true).toBe(true);
  });

  it("should provide recommendations for when to remove deduplication", () => {
    console.log("\n=== RECOMMENDATIONS FOR REMOVING DEDUPLICATION ===");
    console.log("\nThe deduplication logic should be kept until:");
    console.log("\n1. RELAY STANDARDS:");
    console.log(
      "   - NIP-33 (replaceable events) is widely implemented by relays",
    );
    console.log("   - Relays consistently return only the most recent version");
    console.log("   - No major relay implementations return duplicates");

    console.log("\n2. TESTING EVIDENCE:");
    console.log("   - Real-world testing shows relays don't return duplicates");
    console.log("   - Multiple relay operators confirm deduplication behavior");
    console.log("   - No user reports of duplicate content issues");

    console.log("\n3. MONITORING:");
    console.log(
      "   - Add logging to track when deduplication is actually used",
    );
    console.log("   - Monitor relay behavior over time");
    console.log("   - Collect metrics on duplicate events found");

    console.log("\n4. GRADUAL REMOVAL:");
    console.log("   - Make deduplication configurable (on/off)");
    console.log(
      "   - Test with deduplication disabled in controlled environments",
    );
    console.log("   - Monitor for issues before removing completely");

    console.log("\n5. FALLBACK STRATEGY:");
    console.log("   - Keep deduplication as a fallback option");
    console.log("   - Allow users to enable it if they experience issues");
    console.log("   - Maintain the code for potential future use");

    expect(true).toBe(true);
  });
});

describe("Logging and Monitoring Tests", () => {
  it("should verify that logging works when duplicates are found", () => {
    // Mock console.log to capture output
    const consoleSpy = vi.spyOn(console, "log").mockImplementation(() => {});

    // Create events with duplicates
    const duplicateEvents = [
      new MockNDKEvent(
        "event1",
        30041,
        "pubkey1",
        1000,
        "chapter-1",
        "Old version",
      ),
      new MockNDKEvent(
        "event2",
        30041,
        "pubkey1",
        2000,
        "chapter-1",
        "New version",
      ),
      new MockNDKEvent(
        "event3",
        30041,
        "pubkey1",
        1500,
        "chapter-1",
        "Middle version",
      ),
    ];

    const eventSets = [new Set(duplicateEvents as NDKEvent[])];
    const result = deduplicateContentEvents(eventSets);

    // Verify the deduplication worked
    expect(result.size).toBe(1);

    // Verify that logging was called
    expect(consoleSpy).toHaveBeenCalledWith(
      expect.stringContaining(
        "[eventDeduplication] Found 2 duplicate events out of 3 total events",
      ),
    );
    expect(consoleSpy).toHaveBeenCalledWith(
      expect.stringContaining(
        "[eventDeduplication] Reduced to 1 unique coordinates",
      ),
    );

    // Restore console.log
    consoleSpy.mockRestore();
  });

  it("should verify that logging works when no duplicates are found", () => {
    // Mock console.log to capture output
    const consoleSpy = vi.spyOn(console, "log").mockImplementation(() => {});

    // Create events without duplicates
    const uniqueEvents = [
      new MockNDKEvent(
        "event1",
        30041,
        "pubkey1",
        1000,
        "chapter-1",
        "Content 1",
      ),
      new MockNDKEvent(
        "event2",
        30041,
        "pubkey1",
        2000,
        "chapter-2",
        "Content 2",
      ),
    ];

    const eventSets = [new Set(uniqueEvents as NDKEvent[])];
    const result = deduplicateContentEvents(eventSets);

    // Verify no deduplication was needed
    expect(result.size).toBe(2);

    // Verify that logging was called with "no duplicates" message
    expect(consoleSpy).toHaveBeenCalledWith(
      expect.stringContaining(
        "[eventDeduplication] No duplicates found in 2 events",
      ),
    );

    // Restore console.log
    consoleSpy.mockRestore();
  });

  it("should verify that deduplicateAndCombineEvents logging works", () => {
    // Mock console.log to capture output
    const consoleSpy = vi.spyOn(console, "log").mockImplementation(() => {});

    // Create events with duplicates
    const duplicateEvents = [
      new MockNDKEvent(
        "event1",
        30041,
        "pubkey1",
        1000,
        "chapter-1",
        "Old version",
      ),
      new MockNDKEvent(
        "event2",
        30041,
        "pubkey1",
        2000,
        "chapter-1",
        "New version",
      ),
    ];

    const result = deduplicateAndCombineEvents(
      [] as NDKEvent[],
      new Set(),
      new Set(duplicateEvents as NDKEvent[]),
    );

    // Verify the deduplication worked
    expect(result.length).toBe(1);

    // Verify that logging was called
    expect(consoleSpy).toHaveBeenCalledWith(
      expect.stringContaining(
        "[eventDeduplication] deduplicateAndCombineEvents: Found 1 duplicate coordinates",
      ),
    );

    // Restore console.log
    consoleSpy.mockRestore();
  });
});