import { expect, test, type Page } from "@playwright/test";

const apiUrl = "http://localhost:5302/api";

type Rgba = { red: number; green: number; blue: number; alpha: number };

function parseCssColour(value: string): Rgba {
  const parts = value.match(/[\d.]+/g)?.map(Number) ?? [];
  expect(parts.length, `expected an rgb/rgba colour but received ${value}`).toBeGreaterThanOrEqual(3);
  return { red: parts[0], green: parts[1], blue: parts[2], alpha: parts[3] ?? 1 };
}

function composite(foreground: Rgba, background: Rgba): Rgba {
  return {
    red: foreground.red * foreground.alpha + background.red * (1 - foreground.alpha),
    green: foreground.green * foreground.alpha + background.green * (1 - foreground.alpha),
    blue: foreground.blue * foreground.alpha + background.blue * (1 - foreground.alpha),
    alpha: 1,
  };
}

function relativeLuminance(colour: Rgba) {
  const linear = [colour.red, colour.green, colour.blue].map((channel) => {
    const value = channel / 255;
    return value <= 0.04045 ? value / 12.92 : ((value + 0.055) / 1.055) ** 2.4;
  });
  return linear[0] * 0.2126 + linear[1] * 0.7152 + linear[2] * 0.0722;
}

function contrastRatio(foreground: Rgba, background: Rgba) {
  const foregroundLuminance = relativeLuminance(foreground);
  const backgroundLuminance = relativeLuminance(background);
  return (Math.max(foregroundLuminance, backgroundLuminance) + 0.05)
    / (Math.min(foregroundLuminance, backgroundLuminance) + 0.05);
}

async function login(page: Page) {
  await page.goto("/login");
  await page.getByLabel("Email").fill("e2e@example.test");
  await page.getByLabel("Current password").fill("E2ePassword123!");
  await page.getByRole("button", { name: "Sign in", exact: true }).click();
  await expect(page).toHaveURL(/\/dashboard$/);
  await expect(page.getByRole("heading", { name: "Dashboard", exact: true })).toBeVisible();
}

async function csrfHeader(page: Page) {
  const cookie = (await page.context().cookies()).find((value) => value.name === "XSRF-TOKEN");
  expect(cookie, "login should issue a CSRF cookie").toBeTruthy();
  return { "X-CSRF-TOKEN": cookie!.value };
}

test.beforeEach(async ({ page }) => {
  await page.addInitScript(() => window.localStorage.setItem("uiLanguage", "en"));
});

test("login establishes an authenticated session", async ({ page }) => {
  await login(page);
  await expect(page.getByText("e2e@example.test").first()).toBeVisible();
});

test("a saved job can be created through the reviewed UI flow", async ({ page }) => {
  const suffix = Date.now().toString();
  const title = `E2E Engineer ${suffix}`;

  await login(page);
  await page.goto("/jobs");
  await page.getByRole("button", { name: "Add Job" }).click();
  await page.getByRole("button", { name: "Enter details manually" }).click();
  await page.getByLabel("Company").fill(`E2E Company ${suffix}`);
  await page.getByLabel("Job title").fill(title);
  await page.getByRole("button", { name: "Continue" }).click();
  for (let step = 0; step < 3; step += 1) {
    await page.getByRole("button", { name: "Skip and continue" }).click();
  }
  await page.getByRole("button", { name: "Create job", exact: true }).click();

  await expect(page.getByText(title, { exact: true })).toBeVisible();
});

test("the dedicated application workspace survives deep links, long data and unsaved navigation", async ({ page }) => {
  const suffix = Date.now().toString();
  const companyName = `Application Workspace Company With A Deliberately Long Name ${suffix}`;
  const title = `Principal Platform Reliability Engineer For Distributed Customer Systems ${suffix}`;

  await login(page);
  const headers = await csrfHeader(page);
  let companyResponse = await page.request.post(`${apiUrl}/companies`, {
    headers,
    data: { name: companyName, location: "Oslo and remote across Europe", source: "direct" },
  });
  for (let attempt = 0; attempt < 2 && !companyResponse.ok(); attempt += 1) {
    await page.waitForTimeout(250);
    companyResponse = await page.request.post(`${apiUrl}/companies`, {
      headers,
      data: { name: companyName, location: "Oslo and remote across Europe", source: "direct" },
    });
  }
  const company = await companyResponse.json();
  expect(companyResponse.ok(), `company create failed: ${companyResponse.status()} ${JSON.stringify(company)}`).toBeTruthy();

  const jobData = {
    jobTitle: title,
    companyId: company.id,
    status: "Applied",
    location: "Oslo and remote across Europe",
    salary: null,
    salaryMin: null,
    salaryMax: null,
    salaryCurrency: null,
    salaryPeriod: null,
    nextAction: "Prepare a concise application answer",
    followUpAt: null,
    notes: "Ask about platform ownership and the incident response rotation.",
    description: `Build reliable distributed systems. ${"Long responsibility text ".repeat(80)} https://example.test/${"very-long-path-segment/".repeat(12)}`,
    translatedDescription: null,
    descriptionLanguage: "en",
    tags: JSON.stringify([".NET", "Kubernetes", "Incident response"]),
    deadline: null,
    coverLetterText: null,
    jobUrl: "https://example.test/jobs/platform-reliability",
    dateApplied: new Date().toISOString(),
    feedbackRequestedAt: null,
    source: "direct",
    countryCode: "NO",
  };
  let jobResponse = await page.request.post(`${apiUrl}/jobapplications`, { headers, data: jobData });
  for (let attempt = 0; attempt < 2 && !jobResponse.ok(); attempt += 1) {
    await page.waitForTimeout(250);
    jobResponse = await page.request.post(`${apiUrl}/jobapplications`, { headers, data: jobData });
  }
  expect(jobResponse.ok()).toBeTruthy();
  const job = await jobResponse.json();

  await page.goto("/jobs");
  const applicationRow = page.getByRole("row", { name: new RegExp(`Open ${title}`, "i") });
  await applicationRow.focus();
  await page.keyboard.press("Enter");
  await expect(page).toHaveURL(new RegExp(`/jobs/${job.id}$`));
  await expect(page.getByRole("heading", { name: title })).toBeVisible();

  await page.goBack();
  await expect(page).toHaveURL(/\/jobs$/);
  await page.goForward();
  await expect(page).toHaveURL(new RegExp(`/jobs/${job.id}$`));

  const workspaceNav = page.getByRole("navigation", { name: "Workspace sections" });
  await workspaceNav.getByRole("button", { name: "Cover Letter", exact: true }).click();
  await expect(page).toHaveURL(new RegExp(`/jobs/${job.id}\\?section=cover-letter$`));
  await page.getByLabel("Application answer").fill("A reviewed answer that must not be lost.");
  await workspaceNav.getByRole("button", { name: "Match", exact: true }).click();
  await expect(page.getByRole("dialog", { name: "Unsaved application changes" })).toBeVisible();
  await page.getByRole("button", { name: "Keep editing" }).click();
  await expect(page.getByLabel("Application answer")).toHaveValue("A reviewed answer that must not be lost.");
  await page.getByRole("button", { name: "Save application drafts" }).click();
  await expect(page.getByText("Unsaved changes")).toHaveCount(0);

  await page.evaluate(() => window.localStorage.setItem("jobtracker.themeMode", "light"));
  await page.reload();
  for (const width of [375, 768, 1440]) {
    await page.setViewportSize({ width, height: 900 });
    await expect(page.getByRole("heading", { name: title })).toBeVisible();
    const overflow = await page.evaluate(() => document.documentElement.scrollWidth - document.documentElement.clientWidth);
    expect(overflow).toBeLessThanOrEqual(1);
  }

  await page.evaluate(() => window.localStorage.setItem("jobtracker.themeMode", "dark"));
  await page.reload();
  await expect(page.getByLabel("Application answer")).toHaveValue("A reviewed answer that must not be lost.");
  await expect(page.locator("html")).toHaveAttribute("data-color-scheme", "dark");

  for (const width of [375, 768, 1440]) {
    await page.setViewportSize({ width, height: 900 });
    await expect(page.getByRole("heading", { name: title })).toBeVisible();
    const overflow = await page.evaluate(() => document.documentElement.scrollWidth - document.documentElement.clientWidth);
    expect(overflow).toBeLessThanOrEqual(1);
  }

  await workspaceNav.getByRole("button", { name: "Job Details", exact: true }).click();
  await expect(page).toHaveURL(new RegExp(`/jobs/${job.id}\\?section=job-details$`));
  await expect(page.getByText("Ask about platform ownership and the incident response rotation.")).toBeVisible();
  await expect(page.getByText("<<<APPLICATION_ANSWER_DRAFT>>>")).toHaveCount(0);

  await page.getByRole("button", { name: "Back to applications" }).click();
  await expect(page).toHaveURL(/\/jobs$/);
  await expect(page.getByRole("row", { name: new RegExp(`Open ${title}`, "i") })).toBeFocused();

  await page.goto("/jobs/2147483647");
  const missingJobAlert = page.getByRole("alert").filter({ hasText: /Not Found|Could not open this application/i });
  await expect(missingJobAlert).toBeVisible();
  const alertColours = await missingJobAlert.evaluate((element) => {
    const styles = window.getComputedStyle(element);
    const parentStyles = window.getComputedStyle(element.parentElement!);
    return {
      foreground: styles.color,
      background: styles.backgroundColor,
      parentBackground: parentStyles.backgroundColor,
    };
  });
  const alertBackground = composite(parseCssColour(alertColours.background), parseCssColour(alertColours.parentBackground));
  expect(contrastRatio(parseCssColour(alertColours.foreground), alertBackground)).toBeGreaterThanOrEqual(4.5);
  await expect(page.getByRole("button", { name: "Back to applications" })).toBeVisible();
});

test("Career Workspace loads from the authenticated application shell", async ({ page }) => {
  await login(page);
  await page.goto("/career");
  await expect(page.getByRole("heading", { name: "Career Workspace" })).toBeVisible();
  await expect(page.getByRole("link", { name: "Open CV Builder" })).toHaveAttribute("href", "/career/builder");
});

test("a public CV renders anonymously and downloads as PDF", async ({ page }) => {
  await login(page);
  const headers = await csrfHeader(page);
  const create = await page.request.post(`${apiUrl}/cv/variants`, {
    headers,
    data: { name: "E2E Public CV" },
  });
  expect(create.ok()).toBeTruthy();
  const variant = await create.json();

  const publish = await page.request.put(`${apiUrl}/cv/variants/${variant.id}/public`, {
    headers,
    data: { isPublic: true },
  });
  expect(publish.ok()).toBeTruthy();
  const published = await publish.json();

  await page.context().clearCookies();
  await page.setViewportSize({ width: 375, height: 900 });
  await page.goto(`/cv/${published.publicSlug}`);
  const publicCvFrame = page.getByTitle("Public CV");
  await expect(publicCvFrame).toBeVisible();
  const overflow = await page.evaluate(() => document.documentElement.scrollWidth - document.documentElement.clientWidth);
  expect(overflow).toBeLessThanOrEqual(1);
  const publicCvMetrics = await publicCvFrame.evaluate((element) => {
    const frame = element as HTMLIFrameElement;
    return {
      renderedWidth: frame.getBoundingClientRect().width,
      innerOverflow: (frame.contentDocument?.documentElement.scrollWidth ?? 0) - (frame.contentDocument?.documentElement.clientWidth ?? 0),
    };
  });
  expect(publicCvMetrics.renderedWidth).toBeLessThanOrEqual(343);
  expect(publicCvMetrics.innerOverflow).toBeLessThanOrEqual(1);
  await expect(page.getByRole("link", { name: "Download PDF" })).toHaveAttribute("href", /\/pdf$/);
  const pdf = await page.request.get(`${apiUrl}/public-cv/${published.publicSlug}/pdf`);
  expect(pdf.ok()).toBeTruthy();
  expect(pdf.headers()["content-type"]).toContain("application/pdf");
  expect((await pdf.body()).subarray(0, 5).toString()).toBe("%PDF-");
});