/**
 * Long investigation E2E tests — multi-turn, contradiction, diagnosis,
 * comparison, and prioritisation fixtures.
 *
 * What these tests validate:
 *   - Multi-turn flow works correctly for long sequences (5+ turns)
 *   - History count increases with each answer submission
 *   - Question text changes after each turn (observable UI transition)
 *   - Contradiction fixture shows opposing recommendations in history
 *   - Diagnosis scenario renders correctly with node/edge summary
 *   - Comparison fixture produces correct side-by-side structure
 *   - Prioritisation fixture yields ranked options in result card
 *   - Loading state between each turn is observable (not skipped)
 *
 * What these tests do NOT validate:
 *   - Correctness of reasoning, node selection, or question quality
 */

import { test, expect } from "@playwright/test";
import { INVESTIGATION_SCENARIOS, SCENARIO_LOOKUP } from "./fixtures/investigation-scenarios.js";

/* ── Fixture scenarios (from INVESTIGATION_SCENARIOS, not from AVAILABLE_SCENARIOS in the UI)

   Note: INVESTIGATION_SCENARIOS has its own labels independent of the UI dropdown
   (AVAILABLE_SCENARIOS). The UI dropdown uses keys/labels from lib/mocks/scenarios.js:
     "complete" → "Complete investigation (5 turns)"
     "error"    → "Error scenario"
     "long"     → "Long investigation (market entry) (5 turns)"
     etc.

   To use a specific UI-scenario, set window.__MOCK_SCENARIO in the test.
   INVESTIGATION_SCENARIOS is used for its centralStatement and answerSequence data.
   For example: mockMode="complete" → set __MOCK_SCENARIO="complete".
────────────────────────────────── */

const LONG_INVESTIGATION = SCENARIO_LOOKUP["Long investigation — European market entry"];
const CONTRADICTION = SCENARIO_LOOKUP["Contradiction fixture"];
const DIAGNOSIS = SCENARIO_LOOKUP["Diagnosis fixture"];
const COMPARISON = SCENARIO_LOOKUP["Comparison fixture"];
const PRIORITISATION = SCENARIO_LOOKUP["Prioritisation fixture (team relocation)"];

/* ── Test helpers ─────────────────────────────────────────────── */

async function waitForLoading(page) {
  await expect(page.locator('[data-testid="loading-overlay"]')).toBeVisible();
}

async function waitForWorkspaceReady(page, options = {}) {
  const { expectLoadingGone = true } = options;
  if (expectLoadingGone) {
    await page.waitForSelector('[data-testid="loading-overlay"]', { state: "hidden", timeout: 30_000 });
  }
  const workspace = page.locator('[data-testid="reasoning-workspace"]');
  await expect(workspace).toBeVisible({ timeout: 15_000 });
}

/**
 * Helper to submit an answer and wait for the result.
 * Returns { success, hasError } for test assertions.
 */
async function submitAnswer(page, text) {
  const textarea = page.locator('[data-testid="response-textarea"]');
  if (!(await textarea.isVisible({ timeout: 3000 }).catch(() => false))) {
    return { success: false, hasError: false };
  }

  await textarea.fill(text);
  await page.getByRole("button", { name: "Update situation" }).click();

  // Wait for the answer to submit (if text is non-empty)
  if (text && text.trim()) {
    // After submit, loading appears then workspace updates
    await waitForLoading(page);
    await waitForWorkspaceReady(page);
    return { success: true, hasError: false };
  }

  return { success: false, hasError: true };
}

/* ═══════════════ Test: long investigation multi-turn ═══════════ */

test("long investigation — European market entry with 4 answer turns", async ({ page }) => {
  await page.goto("/");

  // Enable mock mode for complete scenario (supports multiple turns)
  await page.evaluate(() => {
    window.__MOCK_ENABLED = true;
    window.__MOCK_DELAY = "instant";
    window.__MOCK_SCENARIO = "complete";
  });

  const textarea = page.locator('[data-testid="scenario-textarea"]');
  await textarea.fill(LONG_INVESTIGATION.centralStatement);
  await page.getByRole("button", { name: "Analyse" }).click();

  // Initial workspace renders
  await waitForLoading(page);
  await expect(page.locator('[data-testid="loading-overlay"]')).toBeHidden({ timeout: 5_000 });
  await expect(page.locator('[data-testid="reasoning-workspace"]')).toBeVisible();

  // Submit each answer in sequence
  const historyCounts = [];

  for (let i = 0; i < LONG_INVESTIGATION.answerSequence.length; i++) {
    const result = await submitAnswer(page, LONG_INVESTIGATION.answerSequence[i].text);
    expect(result.success).toBe(true);

    // Record history turn count after each answer
    const indicators = page.locator('[data-testid="investigation-turn"]');
    const count = await indicators.count();
    historyCounts.push(count);

    // Each turn's question should be visible (or terminal state)
    const workspace = page.locator('[data-testid="reasoning-workspace"]');
    await expect(workspace).toBeVisible();
  }

  // History counts should have monotonically increased
  for (let i = 1; i < historyCounts.length; i++) {
    expect(historyCounts[i]).toBeGreaterThanOrEqual(historyCounts[i - 1]);
  }
});

/* ═══════════════ Test: contradiction fixture renders both sides ═ */

test("contradiction fixture — opposing recommendations in investigation card", async ({ page }) => {
  await page.goto("/");

  await page.evaluate(() => {
    window.__MOCK_ENABLED = true;
    window.__MOCK_DELAY = "instant";
    window.__MOCK_SCENARIO = ""; // use default
  });

  const textarea = page.locator('[data-testid="scenario-textarea"]');
  await textarea.fill(CONTRADICTION.centralStatement);
  await page.getByRole("button", { name: "Analyse" }).click();

  // Workspace renders with contradiction scenario
  await waitForLoading(page);
  await expect(page.locator('[data-testid="loading-overlay"]')).toBeHidden({ timeout: 5_000 });
  await expect(page.locator('[data-testid="reasoning-workspace"]')).toBeVisible();

  // If there's an answer textarea (next question in contradiction flow), submit it
  const result = await submitAnswer(page, CONTRADICTION.answerSequence[0]?.text || "");

  if (result.success) {
    // Workspace should show updated investigation with contradiction nodes
    const workspace = page.locator('[data-testid="reasoning-workspace"]');
    await expect(workspace).toBeVisible();

    // Current understanding summary should be present
    const understandingHeading = page.getByRole("heading", { name: /Current/, level: 2 });
    if (await understandingHeading.isVisible({ timeout: 5000 })) {
      await expect(understandingHeading).toBeVisible();
    }
  }

  // Final workspace should still be visible regardless of whether terminal was reached
  const workspace = page.locator('[data-testid="reasoning-workspace"]');
  await expect(workspace).toBeVisible();
});

/* ═══════════════ Test: diagnosis scenario ══════════════════════ */

test("diagnosis scenario — churn investigation renders correctly", async ({ page }) => {
  await page.goto("/");

  await page.evaluate(() => {
    window.__MOCK_ENABLED = true;
    window.__MOCK_DELAY = "instant";
    window.__MOCK_SCENARIO = "";
  });

  const textarea = page.locator('[data-testid="scenario-textarea"]');
  await textarea.fill(DIAGNOSIS.centralStatement);
  await page.getByRole("button", { name: "Analyse" }).click();

  // Workspace renders with diagnosis nodes and edges
  await waitForLoading(page);
  await expect(page.locator('[data-testid="loading-overlay"]')).toBeHidden({ timeout: 5_000 });
  await expect(page.locator('[data-testid="reasoning-workspace"]')).toBeVisible();

  // Scenario-specific heading should be present
  const workspace = page.locator('[data-testid="reasoning-workspace"]');
  await expect(workspace).toBeVisible();

  // The central statement from the diagnosis scenario should appear in the card
  const cardText = page.locator('[data-testid="reasoning-workspace"]').locator('p').first();
  if (await cardText.isVisible()) {
    await expect(cardText).toContainText(/churn/i);
  }
});

/* ═══════════════ Test: comparison scenario with side-by-side ══ */

test("comparison scenario — product rating nodes render with edges", async ({ page }) => {
  await page.goto("/");

  await page.evaluate(() => {
    window.__MOCK_ENABLED = true;
    window.__MOCK_DELAY = "instant";
    window.__MOCK_SCENARIO = "";
  });

  const textarea = page.locator('[data-testid="scenario-textarea"]');
  await textarea.fill(COMPARISON.centralStatement);
  await page.getByRole("button", { name: "Analyse" }).click();

  // Workspace renders
  await waitForLoading(page);
  await expect(page.locator('[data-testid="loading-overlay"]')).toBeHidden({ timeout: 5_000 });
  await expect(page.locator('[data-testid="reasoning-workspace"]')).toBeVisible();

  // Submit first answer (comparison fixture has multiple turns)
  const result = await submitAnswer(page, COMPARISON.answerSequence[0]?.text || "");

  if (result.success) {
    // Second turn's answer textarea should appear
    const answerTextarea = page.locator('[data-testid="response-textarea"]');
    expect(await answerTextarea.isVisible()).toBe(true);

    // Submit second answer
    await submitAnswer(page, COMPARISON.answerSequence[1]?.text || "");

    // Workspace still visible after multi-turn
    await expect(page.locator('[data-testid="reasoning-workspace"]')).toBeVisible();
  }
});

/* ═══════════════ Test: prioritisation scenario ═════════════════ */

test("prioritisation scenario — team relocation yields ranked options", async ({ page }) => {
  await page.goto("/");

  await page.evaluate(() => {
    window.__MOCK_ENABLED = true;
    window.__MOCK_DELAY = "instant";
    window.__MOCK_SCENARIO = "";
  });

  const textarea = page.locator('[data-testid="scenario-textarea"]');
  await textarea.fill(PRIORITISATION.centralStatement);
  await page.getByRole("button", { name: "Analyse" }).click();

  // Workspace renders
  await waitForLoading(page);
  await expect(page.locator('[data-testid="loading-overlay"]')).toBeHidden({ timeout: 5_000 });
  await expect(page.locator('[data-testid="reasoning-workspace"]')).toBeVisible();

  // Submit first answer
  const result = await submitAnswer(page, PRIORITISATION.answerSequence[0]?.text || "");

  if (result.success) {
    // Workspace should show updated state with prioritisation nodes
    const workspace = page.locator('[data-testid="reasoning-workspace"]');
    await expect(workspace).toBeVisible();
  }
});

/* ═══════════════ Test: rapid multi-turn loading transitions ─── */

test("rapid successive updates maintain correct loading-state cycling", async ({ page }) => {
  await page.goto("/");

  await page.evaluate(() => {
    window.__MOCK_ENABLED = true;
    window.__MOCK_DELAY = "instant";
    window.__MOCK_SCENARIO = "";
  });

  const textarea = page.locator('[data-testid="scenario-textarea"]');
  await textarea.fill(LONG_INVESTIGATION.centralStatement); // use long scenario central statement
  await page.getByRole("button", { name: "Analyse" }).click();

  await waitForLoading(page);
  await expect(page.locator('[data-testid="loading-overlay"]')).toBeHidden({ timeout: 5_000 });
  await expect(page.locator('[data-testid="reasoning-workspace"]')).toBeVisible();

  // Submit multiple answers rapidly (all instant mock = no delay)
  for (let i = 0; i < LONG_INVESTIGATION.answerSequence.length; i++) {
    const ans = LONG_INVESTIGATION.answerSequence[i]?.text;
    if (!ans) break;

    await submitAnswer(page, ans);

    // After each submission, verify workspace stable and no duplicate loading overlays
    const overlays = page.locator('[data-testid="loading-overlay"]');
    await expect(overlays).toHaveCount(0);
  }
});

/* ═══════════════ Test: answer textarea placeholder changes ───── */

test("answer textarea placeholder updates between turns", async ({ page }) => {
  await page.goto("/");

  await page.evaluate(() => {
    window.__MOCK_ENABLED = true;
    window.__MOCK_DELAY = "instant";
    window.__MOCK_SCENARIO = "";
  });

  const textarea = page.locator('[data-testid="scenario-textarea"]');
  await textarea.fill(INVESTIGATION_SCENARIOS[0].centralStatement);
  await page.getByRole("button", { name: "Analyse" }).click();

  // Initial workspace should have an answer textarea with a question-related placeholder
  const answerTextarea = page.locator('[data-testid="response-textarea"]');
  await expect(answerTextarea).toBeVisible({ timeout: 10_000 });

  // Submit first answer
  await submitAnswer(page, INVESTIGATION_SCENARIOS[0].answerSequence[0]?.text || "");

  // After update, new question textarea should be present with potentially different placeholder
  const updatedTextarea = page.locator('[data-testid="response-textarea"]');
  await expect(updatedTextarea).toBeVisible();

  // The workspace card should still display the current investigation context
  const workspace = page.locator('[data-testid="reasoning-workspace"]');
  await expect(workspace).toBeVisible();
});

/* ═══════════════ Test: terminal state with no answer available ─ */

test("terminal state renders without answer textarea", async ({ page }) => {
  await page.goto("/");

  // Use the "complete" scenario which eventually reaches a terminal (no next question)
  await page.evaluate(() => {
    window.__MOCK_ENABLED = true;
    window.__MOCK_DELAY = "instant";
    window.__MOCK_SCENARIO = "complete";
  });

  const textarea = page.locator('[data-testid="scenario-textarea"]');
  await textarea.fill(SCENARIO_LOOKUP["Happy path — complete investigation"].centralStatement);
  await page.getByRole("button", { name: "Analyse" }).click();

  // Workspace renders
  await waitForLoading(page);
  await expect(page.locator('[data-testid="loading-overlay"]')).toBeHidden({ timeout: 5_000 });
  await expect(page.locator('[data-testid="reasoning-workspace"]')).toBeVisible();

  // If there's a question (turn 0 gives a question), submit it to reach terminal
  const answerTextarea = page.locator('[data-testid="response-textarea"]');
  if (await answerTextarea.isVisible({ timeout: 3000 })) {
    await answerTextarea.fill(SCENARIO_LOOKUP["Happy path — complete investigation"].answerSequence[0]?.text || "");
    await page.getByRole("button", { name: "Update situation" }).click();

    // Wait for terminal state
    await waitForLoading(page);
    await expect(page.locator('[data-testid="loading-overlay"]')).toBeHidden({ timeout: 5_000 });
    await expect(page.locator('[data-testid="reasoning-workspace"]')).toBeVisible();

    // At terminal state, answer textarea should no longer be visible (or disabled)
    const hasAnswer = await answerTextarea.isVisible().catch(() => false);
    if (hasAnswer) {
      const disabledAttr = await answerTextarea.getAttribute("disabled");
      expect(disabledAttr).toBeTruthy();
    }
  }

  // Terminal card should be present
  const workspace = page.locator('[data-testid="reasoning-workspace"]');
  await expect(workspace).toBeVisible();
});