import logging
import re
import time
from pathlib import Path

from playwright.sync_api import sync_playwright, Page, Browser

from config import Config

logger = logging.getLogger(__name__)

BASE_URL = "https://secure.backblaze.com"
BILLING_URL = f"{BASE_URL}/billing.htm"

CLOUDFLARE_WAIT_MAX = 60
CLOUDFLARE_POLL_INTERVAL = 2


def _wait_for_cloudflare(page: Page) -> None:
    elapsed = 0
    while elapsed < CLOUDFLARE_WAIT_MAX:
        title = page.title()
        if "Just a moment" not in title:
            return
        logger.debug("Waiting for Cloudflare challenge... (%ds)", elapsed)
        time.sleep(CLOUDFLARE_POLL_INTERVAL)
        elapsed += CLOUDFLARE_POLL_INTERVAL
    raise RuntimeError(
        "Cloudflare challenge did not resolve after %ds. "
        "Try running with --no-headless so you can solve it manually, "
        "or set BROWSER_HEADLESS=false in .env" % CLOUDFLARE_WAIT_MAX
    )


def _goto_with_retry(page: Page, url: str, retries: int = 3) -> None:
    for attempt in range(1, retries + 1):
        try:
            page.goto(url, wait_until="domcontentloaded")
            _wait_for_cloudflare(page)
            return
        except RuntimeError:
            raise
        except Exception as e:
            logger.warning("Navigation attempt %d/%d failed for %s: %s", attempt, retries, url, e)
            if attempt == retries:
                raise
            time.sleep(2 * attempt)


def login(page: Page) -> None:
    logger.info("Logging in to Backblaze...")
    _goto_with_retry(page, f"{BASE_URL}/user_signin.htm")
    page.wait_for_selector("#email", timeout=30000)
    page.fill("#email", Config.BACKBLAZE_EMAIL)
    page.fill("#password", Config.BACKBLAZE_PASSWORD)
    page.click("#submitButton")
    page.wait_for_load_state("domcontentloaded")
    time.sleep(2)
    if "user_signin" in page.url:
        raise RuntimeError("Login failed - check credentials")
    logger.info("Login successful")


def get_group_options(page: Page) -> list[dict]:
    _goto_with_retry(page, BILLING_URL)
    group_select = page.locator("select#groupSelection")
    if group_select.count() == 0:
        return [{"value": "", "label": "default"}]
    options = group_select.locator("option").all()
    groups = []
    for opt in options:
        val = opt.get_attribute("value") or ""
        label = opt.inner_text().strip()
        if val or label:
            groups.append({"value": val, "label": label})
    return groups if groups else [{"value": "", "label": "default"}]


def get_year_options(page: Page) -> list[str]:
    page.wait_for_load_state("domcontentloaded")
    year_select = page.locator("select#yearSelection")
    if year_select.count() == 0:
        return []
    options = year_select.locator("option").all()
    return [opt.get_attribute("value") or opt.inner_text().strip() for opt in options]


def get_invoice_links(page: Page) -> list[dict]:
    links = []
    rows = page.locator("table.billing-table tbody tr, table#billingTable tbody tr, table tbody tr").all()
    for row in rows:
        anchors = row.locator("a[href*='billing_invoice'], a[href*='invoice']").all()
        for anchor in anchors:
            href = anchor.get_attribute("href") or ""
            text = anchor.inner_text().strip()
            if href:
                if not href.startswith("http"):
                    href = f"{BASE_URL}/{href.lstrip('/')}"
                links.append({"url": href, "label": text})

    if not links:
        all_anchors = page.locator("a[href*='invoice']").all()
        for anchor in all_anchors:
            href = anchor.get_attribute("href") or ""
            text = anchor.inner_text().strip()
            if href and "invoice" in href.lower():
                if not href.startswith("http"):
                    href = f"{BASE_URL}/{href.lstrip('/')}"
                links.append({"url": href, "label": text})

    return links


def fill_invoice_fields(page: Page) -> None:
    fields = {
        "vatId": Config.INVOICE_VAT_ID,
        "documentType": Config.INVOICE_DOCUMENT_TYPE,
        "company": Config.INVOICE_COMPANY,
        "notes": Config.INVOICE_NOTES,
    }

    for field_id, value in fields.items():
        if not value:
            continue
        for selector in [
            f"#{field_id}",
            f"input[name='{field_id}']",
            f"textarea[name='{field_id}']",
            f"select[name='{field_id}']",
            f"input[id*='{field_id}' i]",
            f"textarea[id*='{field_id}' i]",
            f"select[id*='{field_id}' i]",
            f"input[name*='{field_id}' i]",
            f"textarea[name*='{field_id}' i]",
            f"select[name*='{field_id}' i]",
        ]:
            el = page.locator(selector).first
            if el.count() > 0:
                tag = el.evaluate("el => el.tagName.toLowerCase()")
                if tag == "select":
                    el.select_option(label=value)
                else:
                    el.fill(value)
                logger.info("Filled field %s", field_id)
                break

    for label_text, value in [
        ("VAT", Config.INVOICE_VAT_ID),
        ("Tax", Config.INVOICE_VAT_ID),
        ("Document Type", Config.INVOICE_DOCUMENT_TYPE),
        ("Type", Config.INVOICE_DOCUMENT_TYPE),
        ("Company", Config.INVOICE_COMPANY),
        ("Notes", Config.INVOICE_NOTES),
        ("Note", Config.INVOICE_NOTES),
    ]:
        if not value:
            continue
        labels = page.locator(f"label:has-text('{label_text}')").all()
        for label in labels:
            for_attr = label.get_attribute("for")
            if for_attr:
                target = page.locator(f"#{for_attr}")
                if target.count() > 0:
                    tag = target.evaluate("el => el.tagName.toLowerCase()")
                    if tag == "select":
                        target.select_option(label=value)
                    else:
                        target.fill(value)
                    logger.info("Filled labeled field '%s' -> #%s", label_text, for_attr)
                    break


def sanitize_filename(name: str) -> str:
    name = re.sub(r'[<>:"/\\|?*]', '_', name)
    name = re.sub(r'\s+', '_', name)
    return name.strip('_')


def export_invoice_pdf(page: Page, invoice_url: str, output_path: Path) -> Path:
    _goto_with_retry(page, invoice_url)
    time.sleep(1)

    fill_invoice_fields(page)
    time.sleep(0.5)

    page.pdf(path=str(output_path), format="A4", print_background=True)
    logger.info("Saved: %s", output_path)
    return output_path


def download_all_invoices() -> list[Path]:
    Config.validate()
    output_dir = Path(Config.OUTPUT_DIR)
    output_dir.mkdir(parents=True, exist_ok=True)
    saved = []

    with sync_playwright() as p:
        browser = p.chromium.launch(
            headless=Config.BROWSER_HEADLESS,
            args=["--disable-blink-features=AutomationControlled"],
        )
        context = browser.new_context(
            user_agent=(
                "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 "
                "(KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36"
            ),
        )
        page = context.new_page()
        page.add_init_script(
            "Object.defineProperty(navigator, 'webdriver', {get: () => undefined})"
        )
        page.set_default_timeout(Config.BROWSER_TIMEOUT)

        login(page)

        _goto_with_retry(page, BILLING_URL)

        groups = get_group_options(page)
        logger.info("Found %d group(s): %s", len(groups), [g["label"] for g in groups])

        for group in groups:
            group_label = sanitize_filename(group["label"])
            group_dir = output_dir / group_label if len(groups) > 1 else output_dir

            if group["value"]:
                _goto_with_retry(page, BILLING_URL)
                group_select = page.locator("select#groupSelection")
                if group_select.count() > 0:
                    group_select.select_option(value=group["value"])
                    page.wait_for_load_state("domcontentloaded")
                    time.sleep(1)

            years = get_year_options(page)
            if not years:
                years = ["all"]
            logger.info("Group '%s' - years: %s", group["label"], years)

            for year in years:
                year_dir = group_dir / year if year != "all" else group_dir

                if year != "all":
                    year_select = page.locator("select#yearSelection")
                    if year_select.count() > 0:
                        year_select.select_option(value=year)
                        page.wait_for_load_state("domcontentloaded")
                        time.sleep(1)

                invoices = get_invoice_links(page)
                logger.info(
                    "Group '%s', Year '%s' - found %d invoice(s)",
                    group["label"], year, len(invoices),
                )

                if not invoices:
                    continue

                year_dir.mkdir(parents=True, exist_ok=True)

                for idx, invoice in enumerate(invoices):
                    label = sanitize_filename(invoice["label"]) or f"invoice_{idx + 1}"
                    pdf_path = year_dir / f"{label}.pdf"

                    if pdf_path.exists():
                        logger.info("Skipping (exists): %s", pdf_path)
                        saved.append(pdf_path)
                        continue

                    try:
                        saved.append(export_invoice_pdf(page, invoice["url"], pdf_path))
                    except Exception:
                        logger.exception("Failed to export: %s", invoice["url"])

                if year != "all":
                    _goto_with_retry(page, BILLING_URL)
                    if group["value"]:
                        group_select = page.locator("select#groupSelection")
                        if group_select.count() > 0:
                            group_select.select_option(value=group["value"])
                            page.wait_for_load_state("domcontentloaded")
                            time.sleep(1)

        browser.close()

    return saved