"""Campaign draft/send helpers for direct mail."""

from __future__ import annotations

import re
from typing import TYPE_CHECKING

from django.urls import reverse
from django.utils import timezone

from contacts.consent import (  # noqa: F401 — re-export for tests + providers
    channel_preferences,
    contact_may_receive,
    make_unsubscribe_token,
    one_click_unsubscribe_url,
    opted_in_contacts,
    parse_unsubscribe_token,
    preferences_url,
    process_unsubscribe_token,
    record_sms_stop,
    set_channel_consent,
    set_channel_preferences,
    unsubscribe_all,
)
from contacts.models import Channel, Contact
from core.scheduling import parse_scheduled_for
from directmail.models import Campaign, Message, MessageTemplate

if TYPE_CHECKING:
    from django.contrib.auth.models import AbstractBaseUser

AUDIENCE_CHANNEL = {
    Campaign.Audience.POSTCARD_OPT_IN: Channel.POSTCARD,
    Campaign.Audience.CARRIER_ROUTE: Channel.POSTCARD,
}

# {{first_name}} preferred; {first_name} also accepted (composer hint legacy).
_MERGE_TAG_RE = re.compile(
    r"\{\{\s*(first_name|last_name|email|phone|full_name)\s*\}\}"
    r"|\{\s*(first_name|last_name|email|phone|full_name)\s*\}",
    re.IGNORECASE,
)

REMOVABLE_MESSAGE_STATUSES = frozenset(
    {
        Message.Status.DRAFT,
        Message.Status.SCHEDULED,
        Message.Status.FAILED,
    }
)


def render_merge_tags(text: str, contact: Contact | None) -> str:
    """Replace personalization tags with contact field values."""
    if not text:
        return text or ""
    first = (getattr(contact, "first_name", None) or "").strip() if contact else ""
    last = (getattr(contact, "last_name", None) or "").strip() if contact else ""
    email = (getattr(contact, "email", None) or "").strip() if contact else ""
    phone = (getattr(contact, "phone", None) or "").strip() if contact else ""
    full = f"{first} {last}".strip()
    values = {
        "first_name": first,
        "last_name": last,
        "email": email,
        "phone": phone,
        "full_name": full,
    }

    def _replace(match: re.Match[str]) -> str:
        key = (match.group(1) or match.group(2) or "").lower()
        return values.get(key, "")

    return _MERGE_TAG_RE.sub(_replace, text)


def message_is_removable(message: Message) -> bool:
    return message.status in REMOVABLE_MESSAGE_STATUSES


def channel_for_audience(audience: str) -> str:
    try:
        return AUDIENCE_CHANNEL[audience]
    except KeyError as exc:
        raise ValueError(f"Unknown audience: {audience}") from exc


def parse_route_targeting(raw: str | dict | None) -> dict:
    """Parse compose JSON for a carrier-route campaign."""
    from directmail.providers.postcard.pcm import MAX_SELECTED_ROUTES

    data: dict = {}
    if isinstance(raw, dict):
        data = raw
    elif isinstance(raw, str) and raw.strip():
        import json

        try:
            parsed = json.loads(raw)
        except json.JSONDecodeError as exc:
            raise ValueError("Carrier route selection is invalid JSON.") from exc
        if not isinstance(parsed, dict):
            raise ValueError("Carrier route selection must be an object.")
        data = parsed
    codes = [
        str(code).strip()
        for code in (data.get("selected_codes") or data.get("routes") or [])
        if str(code).strip()
    ]
    # Allow routes as list of objects from the quote endpoint.
    if not codes and isinstance(data.get("routes"), list):
        codes = [
            str(row.get("code") or "").strip()
            for row in data["routes"]
            if isinstance(row, dict)
        ]
        codes = [c for c in codes if c]
    codes = list(dict.fromkeys(codes))
    if not codes:
        raise ValueError("Select one or two USPS carrier routes.")
    if len(codes) > MAX_SELECTED_ROUTES:
        raise ValueError("Pick at most two carrier routes.")
    try:
        list_count_id = int(data.get("list_count_id") or 0)
        record_count = int(data.get("record_count") or 0)
    except (TypeError, ValueError) as exc:
        raise ValueError("Route quote is missing list count.") from exc
    if list_count_id <= 0 or record_count <= 0:
        raise ValueError("Find routes and select them before saving (need a PCM quote).")
    estimated = data.get("estimated") if isinstance(data.get("estimated"), dict) else {}
    route_rows = data.get("route_rows") if isinstance(data.get("route_rows"), list) else []
    return {
        "selected_codes": codes,
        "list_count_id": list_count_id,
        "record_count": record_count,
        "mail_class": str(data.get("mail_class") or "Standard"),
        "list_type": str(data.get("list_type") or "IRL"),
        "zip": str(data.get("zip") or ""),
        "estimated": estimated,
        "route_rows": route_rows,
    }


def money_total(per_piece: float | None, quantity: int) -> float | None:
    if per_piece is None:
        return None
    return round(float(per_piece) * max(int(quantity or 0), 0), 2)


def postcard_quote(*, action: str, payload: dict) -> dict:
    """Search routes or price a mailing-list / selected-route postcard."""
    from directmail.providers.postcard.pcm import (
        MAX_SELECTED_ROUTES,
        design_pricing,
        extract_crrt_rows,
        list_count_carrier_route,
        list_count_radius,
        list_count_zipcode,
        mail_class_for_size,
        pick_unit_price,
    )
    from directmail.providers.postcard.usps_eddm import (
        USPS_EDDM_MAP_URL,
        enrich_crrt_rows,
    )

    design_id = payload.get("design_id")
    size = str(payload.get("size") or "").strip()
    try:
        design_id_int = int(design_id) if design_id not in (None, "") else None
    except (TypeError, ValueError):
        design_id_int = None

    requested_class = str(payload.get("mail_class") or "").strip()
    mail_class = requested_class or mail_class_for_size(size)
    if mail_class not in {"FirstClass", "Standard"}:
        mail_class = mail_class_for_size(size)
    pricing = design_pricing(design_id_int)

    def _price(qty: int) -> tuple[float | None, str]:
        return pick_unit_price(pricing, mail_class=mail_class, quantity=qty)

    action = (action or "mailing_list").strip()
    if action == "mailing_list":
        count = opted_in_contacts(Channel.POSTCARD).count()
        per_piece, source = _price(count)
        return {
            "action": action,
            "mail_class": mail_class,
            "count": count,
            "per_piece": per_piece,
            "total": money_total(per_piece, count),
            "price_source": source,
        }

    if action == "search":
        zip_code = str(payload.get("zip") or "").strip()
        address = str(payload.get("address") or "").strip()
        city = str(payload.get("city") or "").strip()
        state = str(payload.get("state") or "").strip()
        try:
            miles = float(payload.get("radius") or 0)
        except (TypeError, ValueError):
            miles = 0
        if address and city and state and zip_code and miles > 0:
            data = list_count_radius(
                address=address,
                city=city,
                state=state,
                zip_code=zip_code,
                miles=miles,
            )
        elif zip_code:
            data = list_count_zipcode(zip_codes=[zip_code])
        else:
            raise ValueError("Enter a ZIP code (or address + ZIP + radius).")
        rows = enrich_crrt_rows(extract_crrt_rows(data), zip_hint=zip_code)
        priced = []
        for row in rows:
            per_piece, source = _price(row["total"])
            priced.append(
                {
                    **row,
                    "per_piece": per_piece,
                    "cost": money_total(per_piece, row["total"]),
                    "price_source": source,
                }
            )
        return {
            "action": action,
            "mail_class": mail_class,
            "zip": zip_code,
            "routes": priced,
            "eddm_map_url": USPS_EDDM_MAP_URL,
            "discovery_list_count_id": data.get("listCountID") or data.get("list_count_id"),
        }

    if action == "select":
        codes = [
            str(c).strip()
            for c in (payload.get("routes") or [])
            if str(c).strip()
        ]
        codes = list(dict.fromkeys(codes))
        if not codes:
            raise ValueError("Select at least one carrier route.")
        if len(codes) > MAX_SELECTED_ROUTES:
            raise ValueError("Pick at most two carrier routes.")
        data = list_count_carrier_route(carrier_routes=codes)
        rows = extract_crrt_rows(data)
        if not rows:
            try:
                record_count = int(data.get("recordCount") or data.get("record_count") or 0)
            except (TypeError, ValueError):
                record_count = 0
            rows = [{"code": code, "text": code, "total": 0} for code in codes]
            if record_count and len(rows) == 1:
                rows[0]["total"] = record_count
        rows = enrich_crrt_rows(rows, zip_hint=codes[0] if codes else "")
        record_count = int(data.get("recordCount") or data.get("record_count") or 0)
        if not record_count:
            record_count = sum(int(r.get("total") or 0) for r in rows)
        per_piece, source = _price(record_count)
        priced = []
        for row in rows:
            total = int(row.get("total") or 0)
            priced.append(
                {
                    **row,
                    "per_piece": per_piece,
                    "cost": money_total(per_piece, total),
                    "price_source": source,
                }
            )
        list_count_id = data.get("listCountID") or data.get("list_count_id")
        return {
            "action": action,
            "mail_class": mail_class,
            "selected_codes": codes,
            "routes": priced,
            "route_rows": priced,
            "list_count_id": list_count_id,
            "record_count": record_count,
            "per_piece": per_piece,
            "total": money_total(per_piece, record_count),
            "price_source": source,
            "eddm_map_url": USPS_EDDM_MAP_URL,
            "estimated": {
                "per_piece": per_piece,
                "pieces": record_count,
                "total": money_total(per_piece, record_count),
                "currency": "USD",
                "source": source,
            },
        }

    raise ValueError(f"Unknown quote action: {action}")


def create_campaign_draft(
    *,
    name: str,
    audience: str,
    subject: str = "",
    body: str = "",
    scheduled_for=None,
    created_by: AbstractBaseUser | None = None,
    template: MessageTemplate | None = None,
    route_targeting: dict | None = None,
) -> Campaign:
    """Persist a draft campaign and per-recipient Message stubs."""
    channel = channel_for_audience(audience)
    targeting = route_targeting if isinstance(route_targeting, dict) else {}
    campaign = Campaign.objects.create(
        name=name,
        channel=channel,
        audience=audience,
        status=Campaign.Status.DRAFT,
        scheduled_for=scheduled_for,
        subject_override=subject,
        body_override=body,
        created_by=created_by,
        template=template,
        route_targeting=targeting,
    )
    if audience == Campaign.Audience.CARRIER_ROUTE:
        Message.objects.create(
            campaign=campaign,
            contact=None,
            channel=channel,
            status=Message.Status.DRAFT,
            scheduled_for=scheduled_for,
            body_snapshot=body,
        )
        return campaign
    contacts = list(opted_in_contacts(channel))
    Message.objects.bulk_create(
        [
            Message(
                campaign=campaign,
                contact=contact,
                channel=channel,
                status=Message.Status.DRAFT,
                scheduled_for=scheduled_for,
                body_snapshot=body,
            )
            for contact in contacts
        ]
    )
    return campaign


def campaign_notify_recipient(campaign: Campaign) -> str:
    """Email address for the realtor summary (created_by, else CONTACT_EMAIL)."""
    from django.conf import settings

    user = campaign.created_by
    if user is not None:
        email = (getattr(user, "email", None) or "").strip()
        if email:
            return email
    return (settings.CONTACT_EMAIL or "").strip()


def send_campaign_completion_notify(campaign: Campaign) -> bool:
    """
    One-shot summary email when a campaign finishes sending.

    Returns True if mail was sent (or already sent earlier).
    """
    from django.conf import settings
    from django.core.mail import EmailMultiAlternatives
    from django.db.models import Count, Q
    from django.template.loader import get_template
    from django.urls import reverse

    from public.email_branding import email_brand_context

    campaign.refresh_from_db()
    if campaign.notify_sent_at:
        return True
    if campaign.status != Campaign.Status.COMPLETED:
        return False

    to_email = campaign_notify_recipient(campaign)
    if not to_email:
        return False

    # Claim the notify slot atomically so concurrent refresh calls only send once.
    now = timezone.now()
    claimed = Campaign.objects.filter(
        pk=campaign.pk,
        status=Campaign.Status.COMPLETED,
        notify_sent_at__isnull=True,
    ).update(notify_sent_at=now)
    if not claimed:
        return True
    campaign.notify_sent_at = now

    counts = campaign.messages.aggregate(
        sent=Count(
            "id",
            filter=Q(
                status__in=[
                    Message.Status.SENT,
                    Message.Status.DELIVERED,
                    Message.Status.OPENED,
                    Message.Status.CLICKED,
                ]
            ),
        ),
        delivered=Count(
            "id",
            filter=Q(
                status__in=[
                    Message.Status.DELIVERED,
                    Message.Status.OPENED,
                    Message.Status.CLICKED,
                ]
            ),
        ),
        failed=Count(
            "id",
            filter=Q(
                status__in=[
                    Message.Status.FAILED,
                    Message.Status.BOUNCED,
                ]
            ),
        ),
        suppressed=Count("id", filter=Q(status=Message.Status.SUPPRESSED)),
        total=Count("id"),
    )
    report_path = reverse("directmail:campaign_detail", kwargs={"pk": campaign.pk})
    public = (settings.PUBLIC_SITE_URL or "").rstrip("/")
    report_url = f"{public}{report_path}" if public else report_path

    subject = f"Campaign sent: {campaign.name}"
    ctx = email_brand_context(
        subject=subject,
        campaign_name=campaign.name,
        channel_display=campaign.get_channel_display(),
        total=counts["total"],
        sent=counts["sent"],
        delivered=counts["delivered"],
        failed=counts["failed"],
        suppressed=counts["suppressed"],
        report_url=report_url,
    )
    text_content = get_template("emails/campaign_complete.txt").render(ctx)
    html_content = get_template("emails/campaign_complete.html").render(ctx)
    email = EmailMultiAlternatives(
        subject=subject,
        body=text_content,
        from_email=settings.DEFAULT_FROM_EMAIL,
        to=[to_email],
    )
    email.attach_alternative(html_content, "text/html")
    try:
        email.send(fail_silently=False)
    except Exception:  # noqa: BLE001 — don't block completion on mail errors
        import logging

        logging.getLogger(__name__).exception(
            "Campaign completion notify failed for %s", campaign.pk
        )
        Campaign.objects.filter(pk=campaign.pk).update(notify_sent_at=None)
        campaign.notify_sent_at = None
        return False

    return True


def refresh_campaign_status(campaign: Campaign) -> Campaign:
    """Set campaign to completed when no messages remain pending."""
    campaign.refresh_from_db()
    pending = campaign.messages.filter(
        status__in=[
            Message.Status.DRAFT,
            Message.Status.SCHEDULED,
            Message.Status.QUEUED,
        ]
    ).exists()
    if pending:
        return campaign
    if campaign.status == Campaign.Status.SENDING:
        campaign.status = Campaign.Status.COMPLETED
        campaign.save(update_fields=["status", "updated_at"])
        send_campaign_completion_notify(campaign)
    return campaign


def enqueue_campaign_send(campaign: Campaign) -> int:
    """
    Queue draft/scheduled/failed messages for send.

    Dev uses ImmediateBackend → each enqueue runs inline via SMTP/console.
    """
    from directmail.tasks import send_campaign_message

    sendable = list(
        campaign.messages.filter(
            status__in=[
                Message.Status.DRAFT,
                Message.Status.SCHEDULED,
                Message.Status.FAILED,
            ]
        )
    )
    if not sendable:
        return 0

    campaign.status = Campaign.Status.SENDING
    campaign.save(update_fields=["status", "updated_at"])

    enqueued = 0
    for message in sendable:
        message.status = Message.Status.QUEUED
        message.save(update_fields=["status", "updated_at"])
        try:
            send_campaign_message.enqueue(message_id=str(message.pk))
        except Exception:  # noqa: BLE001 — task already persisted FAILED
            pass
        enqueued += 1

    refresh_campaign_status(campaign)
    return enqueued


def send_campaign_test_email(campaign: Campaign, to_email: str) -> None:
    """Send one preview copy to ``to_email`` without touching recipient rows."""
    from django.conf import settings
    from django.core.mail import EmailMultiAlternatives
    from django.template.loader import get_template

    from public.email_branding import (
        campaign_body_to_email_html,
        campaign_body_to_plain_text,
        email_brand_context,
    )

    if campaign.channel != Channel.EMAIL:
        raise ValueError("Test send is only available for email campaigns.")
    subject = campaign.subject_override or (
        campaign.template.subject if campaign.template_id else f"Message from {settings.SITE_NAME}"
    )
    body = campaign.body_override or (
        campaign.template.body if campaign.template_id else ""
    )
    if not subject.strip():
        raise ValueError("Campaign has no subject.")
    if not body.strip():
        raise ValueError("Campaign has no body.")

    # Preview merge tags using first recipient when available.
    sample = (
        campaign.messages.select_related("contact")
        .order_by("created_at")
        .first()
    )
    sample_contact = sample.contact if sample else None
    subject = render_merge_tags(subject, sample_contact)
    body = render_merge_tags(body, sample_contact)

    notice = (
        "This is a test send from the portal. "
        "Recipient list was not notified."
    )
    ctx = email_brand_context(
        title=f"[TEST] {subject}",
        content=f"{campaign_body_to_plain_text(body)}\n\n{notice}",
        content_html=(
            f"{campaign_body_to_email_html(body)}"
            f'<p style="margin:24px 0 0;color:#6b7280;font-size:13px;">{notice}</p>'
        ),
    )
    text_content = get_template("emails/marketing_email.txt").render(ctx)
    html_content = get_template("emails/marketing_email.html").render(ctx)
    email = EmailMultiAlternatives(
        subject=f"[TEST] {subject}",
        body=text_content,
        from_email=settings.DEFAULT_FROM_EMAIL,
        to=[to_email],
    )
    email.attach_alternative(html_content, "text/html")
    email.send(fail_silently=False)