import { describe, it, before, beforeEach, after } from "node:test";
import assert from "node:assert/strict";
import { mkdtempSync, rmSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";

const tmpDir = mkdtempSync(join(tmpdir(), "omniroute-test-"));
process.env.DATA_DIR = tmpDir;

const core = await import("../../../src/lib/db/core.ts");
core.resetDbInstance();
const { insertCompressionAnalyticsRow, getCompressionAnalyticsSummary } =
  await import("../../../src/lib/db/compressionAnalytics.ts");
const { attachCompressionUsageReceipt } =
  await import("../../../src/lib/db/compressionAnalytics.ts");
const { getDbInstance } = core;

describe("compressionAnalytics", () => {
  before(() => {
    const db = getDbInstance();
    db.exec(`
      CREATE TABLE IF NOT EXISTS compression_analytics (
        id INTEGER PRIMARY KEY AUTOINCREMENT,
        timestamp TEXT NOT NULL,
        combo_id TEXT,
        provider TEXT,
        mode TEXT NOT NULL,
        original_tokens INTEGER NOT NULL,
        compressed_tokens INTEGER NOT NULL,
        tokens_saved INTEGER NOT NULL,
        duration_ms INTEGER,
        request_id TEXT
      )
    `);
  });

  beforeEach(() => {
    // Clear table before each test for full isolation
    const db = getDbInstance();
    db.exec("DELETE FROM compression_analytics");
  });

  after(() => {
    core.closeDbInstance();
    rmSync(tmpDir, { recursive: true, force: true });
  });

  it("empty table returns zeroed summary", () => {
    const summary = getCompressionAnalyticsSummary();
    assert.deepEqual(summary, {
      totalRequests: 0,
      totalTokensSaved: 0,
      avgSavingsPct: 0,
      avgDurationMs: 0,
      byMode: {},
      byEngine: {},
      byCompressionCombo: {},
      byProvider: {},
      last24h: summary.last24h,
      totalSkipped: 0,
      bySkipReason: {},
      validationFallbacks: 0,
      realUsage: {
        requestsWithReceipts: 0,
        promptTokens: 0,
        completionTokens: 0,
        totalTokens: 0,
        cacheReadTokens: 0,
        cacheWriteTokens: 0,
        estimatedUsdSaved: 0,
        bySource: {},
      },
      mcpDescriptionCompression: {
        snapshots: 0,
        estimatedTokensSaved: 0,
      },
    });
    assert.equal(summary.last24h.length, 24);
  });

  it("insert single row does not throw", () => {
    const row = {
      timestamp: new Date().toISOString(),
      mode: "lite",
      original_tokens: 1000,
      compressed_tokens: 800,
      tokens_saved: 200,
    };
    assert.doesNotThrow(() => insertCompressionAnalyticsRow(row));
    const summary = getCompressionAnalyticsSummary();
    assert.equal(summary.totalRequests, 1);
  });

  it("stores all RTK raw output pointers when provided", () => {
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "rtk",
      original_tokens: 1000,
      compressed_tokens: 500,
      tokens_saved: 500,
      rtk_raw_output_pointer: "raw_1",
      rtk_raw_output_bytes: 100,
      rtk_raw_output_pointers: JSON.stringify(["raw_1", "raw_2"]),
      rtk_raw_output_total_bytes: 250,
    });

    const db = getDbInstance();
    const row = db
      .prepare(
        "SELECT rtk_raw_output_pointer, rtk_raw_output_bytes, rtk_raw_output_pointers, rtk_raw_output_total_bytes FROM compression_analytics LIMIT 1"
      )
      .get() as {
      rtk_raw_output_pointer: string;
      rtk_raw_output_bytes: number;
      rtk_raw_output_pointers: string;
      rtk_raw_output_total_bytes: number;
    };

    assert.equal(row.rtk_raw_output_pointer, "raw_1");
    assert.equal(row.rtk_raw_output_bytes, 100);
    assert.equal(row.rtk_raw_output_pointers, JSON.stringify(["raw_1", "raw_2"]));
    assert.equal(row.rtk_raw_output_total_bytes, 250);
  });

  it("summary counts correctly after multiple inserts", () => {
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "lite",
      original_tokens: 1000,
      compressed_tokens: 800,
      tokens_saved: 200,
    });
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "standard",
      original_tokens: 300,
      compressed_tokens: 280,
      tokens_saved: 20,
    });
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "aggressive",
      original_tokens: 500,
      compressed_tokens: 400,
      tokens_saved: 100,
    });
    const summary = getCompressionAnalyticsSummary();
    assert.equal(summary.totalRequests, 3);
  });

  it("totalTokensSaved sums correctly", () => {
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "lite",
      original_tokens: 1000,
      compressed_tokens: 800,
      tokens_saved: 200,
    });
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "standard",
      original_tokens: 300,
      compressed_tokens: 280,
      tokens_saved: 20,
    });
    const summary = getCompressionAnalyticsSummary();
    assert.equal(summary.totalTokensSaved, 220);
  });

  it("byMode groups correctly", () => {
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "lite",
      original_tokens: 1000,
      compressed_tokens: 800,
      tokens_saved: 200,
    });
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "lite",
      original_tokens: 500,
      compressed_tokens: 400,
      tokens_saved: 100,
    });
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "standard",
      original_tokens: 300,
      compressed_tokens: 270,
      tokens_saved: 30,
    });
    const summary = getCompressionAnalyticsSummary();
    assert.equal(summary.byMode["lite"].count, 2);
    assert.equal(summary.byMode["lite"].tokensSaved, 300);
    assert.equal(summary.byMode["standard"].count, 1);
  });

  it("byProvider groups correctly", () => {
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "lite",
      original_tokens: 1000,
      compressed_tokens: 800,
      tokens_saved: 200,
      provider: "ProviderA",
    });
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "lite",
      original_tokens: 500,
      compressed_tokens: 400,
      tokens_saved: 100,
      provider: "ProviderB",
    });
    const summary = getCompressionAnalyticsSummary();
    assert.deepEqual(summary.byProvider["ProviderA"], { count: 1, tokensSaved: 200 });
    assert.deepEqual(summary.byProvider["ProviderB"], { count: 1, tokensSaved: 100 });
  });

  it("since=24h filters rows older than 24h", () => {
    const oldTimestamp = new Date(Date.now() - 48 * 60 * 60 * 1000).toISOString();
    const recentTimestamp = new Date().toISOString();

    insertCompressionAnalyticsRow({
      timestamp: oldTimestamp,
      mode: "lite",
      original_tokens: 2000,
      compressed_tokens: 1800,
      tokens_saved: 200,
    });
    insertCompressionAnalyticsRow({
      timestamp: recentTimestamp,
      mode: "lite",
      original_tokens: 1000,
      compressed_tokens: 900,
      tokens_saved: 100,
    });

    const summary24h = getCompressionAnalyticsSummary("24h");
    assert.equal(summary24h.totalRequests, 1);
    assert.equal(summary24h.totalTokensSaved, 100);
  });

  it("since=undefined returns all rows including old ones", () => {
    const oldTimestamp = new Date(Date.now() - 48 * 60 * 60 * 1000).toISOString();
    const recentTimestamp = new Date().toISOString();

    insertCompressionAnalyticsRow({
      timestamp: oldTimestamp,
      mode: "lite",
      original_tokens: 2000,
      compressed_tokens: 1800,
      tokens_saved: 200,
    });
    insertCompressionAnalyticsRow({
      timestamp: recentTimestamp,
      mode: "lite",
      original_tokens: 1000,
      compressed_tokens: 900,
      tokens_saved: 100,
    });

    const summaryAll = getCompressionAnalyticsSummary();
    assert.equal(summaryAll.totalRequests, 2);
    assert.equal(summaryAll.totalTokensSaved, 300);
  });

  it("avgSavingsPct calculates correctly", () => {
    // 200/1000 = 20%, 100/500 = 20% → avg = 20%
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "lite",
      original_tokens: 1000,
      compressed_tokens: 800,
      tokens_saved: 200,
    });
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "standard",
      original_tokens: 500,
      compressed_tokens: 400,
      tokens_saved: 100,
    });
    const summary = getCompressionAnalyticsSummary();
    assert.equal(summary.avgSavingsPct, 20);
  });

  it("last24h hourly buckets have correct shape", () => {
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "lite",
      original_tokens: 1000,
      compressed_tokens: 800,
      tokens_saved: 200,
    });
    const hourly = getCompressionAnalyticsSummary("24h").last24h;
    assert(Array.isArray(hourly));
    assert(hourly.length <= 24);
    hourly.forEach((bucket) => {
      assert(typeof bucket.hour === "string");
      assert(typeof bucket.count === "number");
      assert(typeof bucket.tokensSaved === "number");
    });
  });

  it("attaches real usage receipts to the latest compression row", () => {
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "standard",
      original_tokens: 1000,
      compressed_tokens: 700,
      tokens_saved: 300,
      request_id: "req-receipt",
    });
    attachCompressionUsageReceipt(
      "req-receipt",
      {
        prompt_tokens: 710,
        completion_tokens: 42,
        total_tokens: 752,
        prompt_tokens_details: { cached_tokens: 100, cache_creation_tokens: 12 },
      },
      "provider"
    );
    const summary = getCompressionAnalyticsSummary();
    assert.equal(summary.realUsage.requestsWithReceipts, 1);
    assert.equal(summary.realUsage.promptTokens, 710);
    assert.equal(summary.realUsage.completionTokens, 42);
    assert.equal(summary.realUsage.totalTokens, 752);
    assert.equal(summary.realUsage.cacheReadTokens, 100);
    assert.equal(summary.realUsage.cacheWriteTokens, 12);
    assert.equal(summary.realUsage.bySource.provider, 1);
  });

  it("aggregates estimated USD savings separately from token estimates", () => {
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "standard",
      original_tokens: 1000,
      compressed_tokens: 700,
      tokens_saved: 300,
      request_id: "req-usd",
      estimated_usd_saved: 0.0015,
    });
    attachCompressionUsageReceipt("req-usd", { prompt_tokens: 700, total_tokens: 700 }, "provider");

    const summary = getCompressionAnalyticsSummary();
    assert.equal(summary.realUsage.requestsWithReceipts, 1);
    assert.equal(summary.realUsage.estimatedUsdSaved, 0.0015);
  });

  it("summarizes validation fallback and output mode rows", () => {
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "output-caveman",
      original_tokens: 900,
      compressed_tokens: 900,
      tokens_saved: 0,
      request_id: "req-output",
      validation_fallback: true,
      output_mode: "full",
    });
    attachCompressionUsageReceipt(
      "req-output",
      { prompt_tokens: 900, completion_tokens: 120, total_tokens: 1020 },
      "provider"
    );

    const summary = getCompressionAnalyticsSummary();
    assert.equal(summary.validationFallbacks, 1);
    assert.equal(summary.byMode["output-caveman"].count, 1);
    assert.equal(summary.realUsage.requestsWithReceipts, 1);
    assert.equal(summary.realUsage.totalTokens, 1020);
  });

  it("summarizes MCP description estimates without counting them as provider receipts", () => {
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "mcp-description",
      engine: "mcp-description",
      original_tokens: 20,
      compressed_tokens: 12,
      tokens_saved: 8,
      mcp_description_tokens_saved: 8,
    });

    const summary = getCompressionAnalyticsSummary();
    assert.equal(summary.mcpDescriptionCompression.snapshots, 1);
    assert.equal(summary.mcpDescriptionCompression.estimatedTokensSaved, 8);
    assert.equal(summary.realUsage.requestsWithReceipts, 0);
    assert.equal(summary.realUsage.bySource.mcp_metadata_estimate, undefined);
  });

  // #4268: attempted-but-no-op runs are recorded with skip_reason so Stacked is
  // visible even when it saves nothing, while saving aggregates stay net-saving-only.
  it("records skipped (no-op) runs separately without polluting saving aggregates", () => {
    // One real saving run...
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "stacked",
      original_tokens: 1000,
      compressed_tokens: 600,
      tokens_saved: 400,
    });
    // ...and two no-op stacked attempts (saved nothing).
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "stacked",
      original_tokens: 500,
      compressed_tokens: 500,
      tokens_saved: 0,
      skip_reason: "no_savings",
    });
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "stacked",
      original_tokens: 800,
      compressed_tokens: 800,
      tokens_saved: 0,
      skip_reason: "no_savings",
    });

    const summary = getCompressionAnalyticsSummary();

    // Saving aggregates count the net-saving run ONLY (skip rows excluded).
    assert.equal(summary.totalRequests, 1, "totalRequests must exclude skip rows");
    assert.equal(summary.totalTokensSaved, 400);
    assert.equal(summary.byMode.stacked.count, 1, "byMode count excludes skip rows");
    assert.equal(summary.byMode.stacked.tokensSaved, 400);

    // ...but the skips are now visible instead of dropped.
    assert.equal(summary.byMode.stacked.skipped, 2, "skipped attempts surfaced per mode");
    assert.equal(summary.totalSkipped, 2);
    assert.equal(summary.bySkipReason.no_savings, 2);
  });

  it("a mode with only no-op runs still appears (count 0, skipped > 0)", () => {
    insertCompressionAnalyticsRow({
      timestamp: new Date().toISOString(),
      mode: "stacked",
      original_tokens: 300,
      compressed_tokens: 300,
      tokens_saved: 0,
      skip_reason: "no_savings",
    });

    const summary = getCompressionAnalyticsSummary();
    assert.equal(summary.totalRequests, 0, "no net-saving runs");
    assert.ok(summary.byMode.stacked, "stacked must appear even with only skip rows");
    assert.equal(summary.byMode.stacked.count, 0);
    assert.equal(summary.byMode.stacked.skipped, 1);
    assert.equal(summary.totalSkipped, 1);
  });
});