import { describe, it } from "node:test";
import assert from "node:assert/strict";
import { parseLinkedInCSV } from "../src/parsers/csv-parser.js";
import { join, dirname } from "node:path";
import { fileURLToPath } from "node:url";

const __dirname = dirname(fileURLToPath(import.meta.url));
const fixturesDir = join(__dirname, "fixtures");

describe("CSV Parser", () => {
  it("should parse standard CSV export", () => {
    const filePath = join(fixturesDir, "sample-export.csv");
    const batch = parseLinkedInCSV(filePath, "sample-export.csv");

    assert.equal(batch.postCount, 8, "Should have 8 posts");
    assert.equal(batch.posts.length, 8, "Posts array should have 8 items");
    assert.equal(batch.exportFilename, "sample-export.csv");
    assert.ok(batch.batchId, "Should have a batchId");
    assert.ok(batch.importedAt, "Should have importedAt timestamp");

    // Check first post
    const firstPost = batch.posts[0];
    assert.ok(firstPost.id, "Post should have an ID");
    assert.ok(
      firstPost.title.includes("uncomfortable truth"),
      "Title should match"
    );
    assert.equal(firstPost.publishedDate, "2026-01-28");
    assert.equal(firstPost.metrics.impressions, 4523);
    assert.equal(firstPost.metrics.reactions, 87);
    assert.equal(firstPost.metrics.comments, 23);
    assert.equal(firstPost.metrics.shares, 12);
    assert.equal(firstPost.metrics.clicks, 156);
    assert.ok(firstPost.metrics.engagementRate > 0, "Should have engagement rate");
  });

  it("should handle European format", () => {
    const filePath = join(fixturesDir, "european-export.csv");
    const batch = parseLinkedInCSV(filePath, "european-export.csv");

    assert.equal(batch.postCount, 2, "Should have 2 posts");

    // Check that European number format is parsed correctly
    const firstPost = batch.posts[0];
    assert.equal(firstPost.metrics.impressions, 4523, "Should parse 4.523 as 4523");
    assert.equal(firstPost.publishedDate, "2026-01-28", "Should normalize date from DD.MM.YYYY");

    const secondPost = batch.posts[1];
    assert.equal(secondPost.metrics.impressions, 2891, "Should parse 2.891 as 2891");
    assert.equal(secondPost.publishedDate, "2026-01-26", "Should normalize date from DD.MM.YYYY");
  });

  it("should handle empty CSV", () => {
    const filePath = join(fixturesDir, "empty-export.csv");
    const batch = parseLinkedInCSV(filePath, "empty-export.csv");

    assert.equal(batch.postCount, 0, "Should have 0 posts");
    assert.equal(batch.posts.length, 0, "Posts array should be empty");
    assert.equal(batch.dateRange.from, "", "Date range from should be empty");
    assert.equal(batch.dateRange.to, "", "Date range to should be empty");
  });

  it("should handle BOM", () => {
    const filePath = join(fixturesDir, "bom-export.csv");
    const batch = parseLinkedInCSV(filePath, "bom-export.csv");

    assert.equal(batch.postCount, 8, "Should parse BOM file correctly");
    assert.ok(
      batch.posts[0].title.includes("uncomfortable truth"),
      "Should parse first post correctly despite BOM"
    );
  });

  it("should calculate engagement rate", () => {
    const filePath = join(fixturesDir, "sample-export.csv");
    const batch = parseLinkedInCSV(filePath, "sample-export.csv");

    const firstPost = batch.posts[0];
    // (87+23+12+156)/4523 * 100 = 6.14...
    const expectedRate = ((87 + 23 + 12 + 156) / 4523) * 100;
    assert.ok(
      Math.abs(firstPost.metrics.engagementRate - expectedRate) < 0.01,
      `Engagement rate should be ~${expectedRate}, got ${firstPost.metrics.engagementRate}`
    );
  });

  it("should generate deterministic post IDs", () => {
    const filePath = join(fixturesDir, "sample-export.csv");
    const batch1 = parseLinkedInCSV(filePath, "sample-export.csv");
    const batch2 = parseLinkedInCSV(filePath, "sample-export.csv");

    // Same post should have same ID
    assert.equal(
      batch1.posts[0].id,
      batch2.posts[0].id,
      "Same post should generate same ID"
    );

    // Different posts should have different IDs
    assert.notEqual(
      batch1.posts[0].id,
      batch1.posts[1].id,
      "Different posts should have different IDs"
    );
  });

  it("should normalize dates to YYYY-MM-DD", () => {
    const filePath = join(fixturesDir, "sample-export.csv");
    const batch = parseLinkedInCSV(filePath, "sample-export.csv");

    // All dates should be in YYYY-MM-DD format
    batch.posts.forEach((post) => {
      assert.match(
        post.publishedDate,
        /^\d{4}-\d{2}-\d{2}$/,
        `Date ${post.publishedDate} should be in YYYY-MM-DD format`
      );
    });

    // Check date range
    assert.equal(batch.dateRange.from, "2026-01-13", "Date range from should be earliest date");
    assert.equal(batch.dateRange.to, "2026-01-28", "Date range to should be latest date");
  });
});

describe("Saves (manual-entry, optional)", () => {
  it("should parse a Saves column when the user augments the CSV with it", () => {
    const filePath = join(fixturesDir, "saves-export.csv");
    const batch = parseLinkedInCSV(filePath, "saves-export.csv");

    assert.equal(batch.postCount, 2, "Should have 2 posts");

    // Row 1 carries a saves count read from native LinkedIn analytics.
    assert.equal(batch.posts[0].metrics.saves, 42, "Should parse the Saves cell value");
  });

  it("should leave saves undefined when the Saves cell is blank (unknown != zero)", () => {
    const filePath = join(fixturesDir, "saves-export.csv");
    const batch = parseLinkedInCSV(filePath, "saves-export.csv");

    // Row 2's Saves cell is empty — saves is unknown, NOT zero.
    assert.equal(
      batch.posts[1].metrics.saves,
      undefined,
      "Blank Saves cell must stay undefined, never coerced to 0"
    );
  });

  it("should leave saves undefined for a standard export with no Saves column (backward-compat)", () => {
    const filePath = join(fixturesDir, "sample-export.csv");
    const batch = parseLinkedInCSV(filePath, "sample-export.csv");

    for (const post of batch.posts) {
      assert.equal(
        post.metrics.saves,
        undefined,
        "Existing CSV exports without a Saves column must round-trip unchanged"
      );
    }
  });

  it("should NOT fold saves into engagementRate (kept comparable to historical data)", () => {
    const filePath = join(fixturesDir, "saves-export.csv");
    const batch = parseLinkedInCSV(filePath, "saves-export.csv");

    // Row 1: (100+30+15+200)/5000 * 100 = 6.9 — saves (42) must NOT be in the numerator.
    const expectedRate = ((100 + 30 + 15 + 200) / 5000) * 100;
    assert.ok(
      Math.abs(batch.posts[0].metrics.engagementRate - expectedRate) < 0.01,
      `engagementRate should exclude saves (~${expectedRate}), got ${batch.posts[0].metrics.engagementRate}`
    );
  });

  it("should treat an explicit '0' Saves cell as a genuine zero (not undefined)", () => {
    const filePath = join(fixturesDir, "saves-edge-export.csv");
    const batch = parseLinkedInCSV(filePath, "saves-edge-export.csv");

    // A literal 0 in the Saves column is a real reading — zero saves, not unknown.
    assert.equal(batch.posts[0].metrics.saves, 0, "Explicit '0' must stay 0, not collapse to undefined");
  });

  it("should leave saves undefined for a non-numeric Saves cell (unknown, never coerced to 0)", () => {
    const filePath = join(fixturesDir, "saves-edge-export.csv");
    const batch = parseLinkedInCSV(filePath, "saves-edge-export.csv");

    // "n/a" is not a count — saves stays unknown, NOT silently flattened to 0.
    assert.equal(
      batch.posts[1].metrics.saves,
      undefined,
      "Non-numeric Saves cell must stay undefined — never coerced to 0"
    );
  });
});

/**
 * Out-of-network reach (manual-entry, optional) — N16.
 *
 * LinkedIn surfaces the in-network/out-of-network split natively in post
 * analytics (Discovery section, under Impressions; progressive global rollout
 * from June 2026) as a PERCENTAGE split — not as two absolute counts, and not
 * in the CSV export. So the ingest is a percent cell the operator transcribes,
 * and the stored field is a single share: `outOfNetworkPct`. In-network is its
 * complement by definition, so storing both halves would only invite a
 * self-contradicting record.
 */
describe("Out-of-network reach (manual-entry, optional)", () => {
  it("should parse an Out-of-network percent cell written with a % suffix", () => {
    const filePath = join(fixturesDir, "reach-export.csv");
    const batch = parseLinkedInCSV(filePath, "reach-export.csv");

    assert.equal(batch.postCount, 4, "Should have 4 posts");
    assert.equal(
      batch.posts[0].metrics.outOfNetworkPct,
      37,
      "'37%' must parse to the number 37"
    );
  });

  it("should leave outOfNetworkPct undefined when the cell is blank (unknown != zero)", () => {
    const filePath = join(fixturesDir, "reach-export.csv");
    const batch = parseLinkedInCSV(filePath, "reach-export.csv");

    assert.equal(
      batch.posts[1].metrics.outOfNetworkPct,
      undefined,
      "Blank Out-of-network cell must stay undefined, never coerced to 0"
    );
  });

  it("should treat an explicit '0' as a genuine zero share (nothing left the network)", () => {
    const filePath = join(fixturesDir, "reach-export.csv");
    const batch = parseLinkedInCSV(filePath, "reach-export.csv");

    assert.equal(
      batch.posts[2].metrics.outOfNetworkPct,
      0,
      "Explicit '0' is a real reading — must stay 0, not collapse to undefined"
    );
  });

  it("should read a European decimal comma as a decimal, not a thousands separator", () => {
    const filePath = join(fixturesDir, "reach-export.csv");
    const batch = parseLinkedInCSV(filePath, "reach-export.csv");

    // A share never carries a thousands separator, so "36,5" is 36.5 percent.
    // parseOptionalCount's US-thousands rule would read this as 365 — wrong here.
    assert.equal(
      batch.posts[3].metrics.outOfNetworkPct,
      36.5,
      "'36,5' must parse to 36.5 percent, never 365"
    );
  });

  it("should leave outOfNetworkPct undefined for a standard export with no reach column (backward-compat)", () => {
    const filePath = join(fixturesDir, "sample-export.csv");
    const batch = parseLinkedInCSV(filePath, "sample-export.csv");

    for (const post of batch.posts) {
      assert.equal(
        post.metrics.outOfNetworkPct,
        undefined,
        "Existing CSV exports without a reach column must round-trip unchanged"
      );
    }
  });

  it("should leave outOfNetworkPct undefined for a non-numeric cell (unknown, never 0)", () => {
    const filePath = join(fixturesDir, "reach-edge-export.csv");
    const batch = parseLinkedInCSV(filePath, "reach-edge-export.csv");

    assert.equal(
      batch.posts[0].metrics.outOfNetworkPct,
      undefined,
      "Non-numeric reach cell must stay undefined — never coerced to 0"
    );
  });

  it("should refuse a value above 100 — a count and a share are undecidable in one column", () => {
    const filePath = join(fixturesDir, "reach-edge-export.csv");
    const batch = parseLinkedInCSV(filePath, "reach-edge-export.csv");

    // "1234" in a share column is almost certainly an absolute impression count.
    // We cannot tell which, so the honest answer is unknown — never a guess.
    assert.equal(
      batch.posts[1].metrics.outOfNetworkPct,
      undefined,
      "A share above 100 must stay undefined, never stored as-is"
    );
  });

  it("should leave outOfNetworkPct undefined for a negative cell", () => {
    const filePath = join(fixturesDir, "reach-edge-export.csv");
    const batch = parseLinkedInCSV(filePath, "reach-edge-export.csv");

    assert.equal(
      batch.posts[2].metrics.outOfNetworkPct,
      undefined,
      "A negative share is not a real reading — must stay undefined"
    );
  });

  it("should accept exactly 100 as a real reading (the boundary is inclusive)", () => {
    const filePath = join(fixturesDir, "reach-edge-export.csv");
    const batch = parseLinkedInCSV(filePath, "reach-edge-export.csv");

    assert.equal(
      batch.posts[3].metrics.outOfNetworkPct,
      100,
      "100 percent out-of-network is possible and must be kept"
    );
  });

  it("should derive outOfNetworkPct from an In-network column as its complement", () => {
    const filePath = join(fixturesDir, "reach-in-network-export.csv");
    const batch = parseLinkedInCSV(filePath, "reach-in-network-export.csv");

    // The operator transcribed the other half of the same split.
    assert.equal(
      batch.posts[0].metrics.outOfNetworkPct,
      37,
      "'In-network 63%' must store out-of-network 37"
    );
    assert.equal(
      batch.posts[1].metrics.outOfNetworkPct,
      undefined,
      "A blank In-network cell leaves neither half known"
    );
  });

  it("should keep the out-of-network half when both columns agree", () => {
    const filePath = join(fixturesDir, "reach-both-export.csv");
    const batch = parseLinkedInCSV(filePath, "reach-both-export.csv");

    assert.equal(
      batch.posts[0].metrics.outOfNetworkPct,
      37,
      "63 + 37 = 100 is consistent — keep the out-of-network reading"
    );
  });

  it("should refuse a contradictory split rather than pick a half", () => {
    const filePath = join(fixturesDir, "reach-both-export.csv");
    const batch = parseLinkedInCSV(filePath, "reach-both-export.csv");

    // 63 + 20 = 83. One of the two cells is a misreading and we cannot tell
    // which, so the record stays unknown instead of silently trusting one.
    assert.equal(
      batch.posts[1].metrics.outOfNetworkPct,
      undefined,
      "A split that does not sum to ~100 must stay undefined"
    );
  });

  it("should tolerate one point of rounding slack between the two halves", () => {
    const filePath = join(fixturesDir, "reach-both-export.csv");
    const batch = parseLinkedInCSV(filePath, "reach-both-export.csv");

    // 62 + 37 = 99: the UI rounds each half independently, so a one-point gap
    // is rounding, not a misreading.
    assert.equal(
      batch.posts[2].metrics.outOfNetworkPct,
      37,
      "A 99 or 101 sum is rounding slack — keep the out-of-network reading"
    );
  });

  it("should NOT fold out-of-network reach into engagementRate", () => {
    const filePath = join(fixturesDir, "reach-export.csv");
    const batch = parseLinkedInCSV(filePath, "reach-export.csv");

    // Row 1: (100+30+15+200)/5000 * 100 = 6.9. Reach is a distribution signal,
    // not engagement — it must not touch the rate.
    const expectedRate = ((100 + 30 + 15 + 200) / 5000) * 100;
    assert.ok(
      Math.abs(batch.posts[0].metrics.engagementRate - expectedRate) < 0.01,
      `engagementRate should exclude reach (~${expectedRate}), got ${batch.posts[0].metrics.engagementRate}`
    );
  });
});