"""Service layer for the Mail plugin: encryption, IMAP sync, SMTP send, rules, vacation, PGP."""

from __future__ import annotations

import base64
import json
import os
import re
import uuid
from datetime import UTC, datetime, timedelta
from email import message_from_bytes
from email.message import EmailMessage
from email.utils import formataddr, formatdate, make_msgid

import aioimaplib
import aiosmtplib
import nh3
import pgpy
from cryptography.fernet import Fernet
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
from sqlalchemy import and_, or_, select, text
from sqlalchemy.ext.asyncio import AsyncSession

from app.plugins.builtins.mail.models import (
    Mail,
    MailAccount,
    MailAttachment,
    MailFolder,
    MailLabel,
    MailLabelAssignment,
    MailRule,
    MailSignature,
    MailTemplate,
    VacationSentLog,
)

# ─── AES-256 Encryption (Fernet) ───

MAIL_ENCRYPTION_KEY = os.environ.get("MAIL_ENCRYPTION_KEY", "leocrm-mail-encryption-key-2024")


def _derive_key(password: str, salt: bytes = b"leocrm-mail-salt") -> bytes:
    """Derive a 32-byte Fernet key from a password using PBKDF2."""
    kdf = PBKDF2HMAC(
        algorithm=hashes.SHA256(),
        length=32,
        salt=salt,
        iterations=480000,
    )
    return base64.urlsafe_b64encode(kdf.derive(password.encode()))


_fernet = Fernet(_derive_key(MAIL_ENCRYPTION_KEY))


def encrypt_password(plaintext: str) -> str:
    """Encrypt a password using AES-256 (Fernet). Returns base64 ciphertext."""
    return _fernet.encrypt(plaintext.encode()).decode()


def decrypt_password(ciphertext: str) -> str:
    """Decrypt a password encrypted with encrypt_password."""
    return _fernet.decrypt(ciphertext.encode()).decode()


# ─── HTML Sanitization (F-MAIL: no script tags) ───


def sanitize_html(raw_html: str) -> str:
    """Sanitize HTML using nh3 — removes script tags and dangerous attributes."""
    if not raw_html:
        return ""
    return nh3.clean(
        raw_html,
        tags={
            "a",
            "b",
            "br",
            "div",
            "em",
            "h1",
            "h2",
            "h3",
            "h4",
            "h5",
            "h6",
            "hr",
            "i",
            "img",
            "li",
            "ol",
            "p",
            "span",
            "strong",
            "table",
            "tbody",
            "td",
            "th",
            "thead",
            "tr",
            "u",
            "ul",
            "blockquote",
            "code",
            "pre",
            "font",
            "center",
        },
        attributes={
            "a": {"href", "title", "target"},
            "img": {"src", "alt", "width", "height"},
            "span": {"style"},
            "div": {"style"},
            "font": {"color", "size", "face"},
            "p": {"style"},
            "td": {"style"},
            "th": {"style"},
        },
    )


# ─── Mail Account Service ───


async def create_mail_account(
    db: AsyncSession, *, tenant_id: uuid.UUID, user_id: uuid.UUID, data: dict
) -> MailAccount:
    """Create a new mail account with encrypted password."""
    account = MailAccount(
        tenant_id=tenant_id,
        user_id=user_id,
        email_address=data["email_address"],
        display_name=data.get("display_name", ""),
        imap_host=data["imap_host"],
        imap_port=data.get("imap_port", 993),
        imap_ssl=data.get("imap_ssl", True),
        smtp_host=data["smtp_host"],
        smtp_port=data.get("smtp_port", 587),
        smtp_tls=data.get("smtp_tls", True),
        username=data["username"],
        encrypted_password=encrypt_password(data["password"]),
        is_shared=data.get("is_shared", False),
        is_active=True,
    )
    db.add(account)
    await db.flush()

    # Create standard folders
    for fname, imap_name in [
        ("Posteingang", "INBOX"),
        ("Postausgang", "Sent"),
        ("Entwürfe", "Drafts"),
        ("Spam", "Spam"),
    ]:
        folder = MailFolder(
            tenant_id=tenant_id,
            account_id=account.id,
            name=fname,
            imap_name=imap_name,
            is_standard=True,
        )
        db.add(folder)
    await db.flush()
    return account


async def update_mail_account(db: AsyncSession, account: MailAccount, data: dict) -> MailAccount:
    """Update a mail account, encrypting password if changed."""
    for field in [
        "email_address",
        "display_name",
        "imap_host",
        "imap_port",
        "imap_ssl",
        "smtp_host",
        "smtp_port",
        "smtp_tls",
        "username",
        "is_shared",
        "is_active",
    ]:
        if field in data and data[field] is not None:
            setattr(account, field, data[field])
    if "password" in data and data["password"] is not None:
        account.encrypted_password = encrypt_password(data["password"])
    await db.flush()
    await db.refresh(account)
    return account


async def get_account_password(account: MailAccount) -> str:
    """Decrypt and return the account password (internal use only)."""
    return decrypt_password(account.encrypted_password)


def account_to_response(account: MailAccount) -> dict:
    """Convert MailAccount to response dict, NEVER including password."""
    return {
        "id": str(account.id),
        "email_address": account.email_address,
        "display_name": account.display_name,
        "imap_host": account.imap_host,
        "imap_port": account.imap_port,
        "imap_ssl": account.imap_ssl,
        "smtp_host": account.smtp_host,
        "smtp_port": account.smtp_port,
        "smtp_tls": account.smtp_tls,
        "username": account.username,
        "is_shared": account.is_shared,
        "is_active": account.is_active,
        "created_at": account.created_at,
        "updated_at": account.updated_at,
    }


# ─── IMAP Sync Service (F-MAIL-01) ───


async def imap_sync_account(
    db: AsyncSession,
    account_id: uuid.UUID,
    tenant_id: uuid.UUID,
) -> dict:
    """Sync mail folders and messages from IMAP server.

    This function is designed to be called as an ARQ background job.
    In tests it is mocked — real implementation connects via aioimaplib.
    """
    account = (
        await db.execute(
            select(MailAccount).where(
                and_(MailAccount.id == account_id, MailAccount.tenant_id == tenant_id)
            )
        )
    ).scalar_one_or_none()
    if not account:
        return {"synced": 0, "error": "Account not found"}

    password = await get_account_password(account)

    # Import aioimaplib here so tests can mock it
    try:
        client = aioimaplib.IMAP4_SSL(host=account.imap_host, port=account.imap_port)
        await client.wait_hello_from_server()
        await client.login(account.username, password)
        await client.select("INBOX")

        # Fetch all message UIDs
        response = await client.uid_search("ALL")
        uids = response[1][0].split() if response[1] and response[1][0] else []

        synced_count = 0
        for uid in uids:
            uid_str = uid.decode() if isinstance(uid, bytes) else str(uid)
            fetch_resp = await client.uid('fetch', uid_str, '(RFC822)')
            raw_email = None
            # aioimaplib Response lines: [header_bytes, data_bytearray, closing_bytes, completion_bytes]
            for line in (fetch_resp.lines if hasattr(fetch_resp, 'lines') else fetch_resp):
                if isinstance(line, bytearray):
                    raw_email = bytes(line)
                    break
            if raw_email is None:
                continue
            if isinstance(raw_email, str):
                raw_email = raw_email.encode()

            msg = message_from_bytes(raw_email)
            body_text = ""
            body_html = ""
            attachments = []

            if msg.is_multipart():
                for part in msg.walk():
                    ct = part.get_content_type()
                    if ct == "text/plain":
                        body_text = part.get_payload(decode=True).decode("utf-8", errors="replace")
                    elif ct == "text/html":
                        body_html = part.get_payload(decode=True).decode("utf-8", errors="replace")
                    elif part.get_filename():
                        attachments.append(
                            {
                                "filename": part.get_filename(),
                                "mime_type": ct,
                                "size": len(part.get_payload(decode=True) or b""),
                            }
                        )
            else:
                ct = msg.get_content_type()
                payload = msg.get_payload(decode=True)
                if payload:
                    decoded = payload.decode("utf-8", errors="replace")
                    if ct == "text/html":
                        body_html = decoded
                    else:
                        body_text = decoded

            message_id = msg.get("Message-ID", make_msgid())
            subject = msg.get("Subject", "")
            from_addr = msg.get("From", "")
            to_addrs = msg.get("To", "")
            cc_addrs = msg.get("Cc", "")
            refs = msg.get("References", "")
            in_reply_to = msg.get("In-Reply-To")
            msg.get("Date", "")

            # Compute thread_id from References/In-Reply-To
            thread_id = _compute_thread_id(message_id, refs, in_reply_to)

            # Get INBOX folder for this account
            folder = (
                await db.execute(
                    select(MailFolder).where(
                        and_(
                            MailFolder.account_id == account.id,
                            MailFolder.imap_name == "INBOX",
                        )
                    )
                )
            ).scalar_one_or_none()
            if folder is None:
                continue

            mail = Mail(
                tenant_id=tenant_id,
                account_id=account.id,
                folder_id=folder.id,
                message_id=message_id,
                thread_id=thread_id,
                in_reply_to=in_reply_to,
                references_header=refs,
                subject=subject,
                from_address=from_addr,
                to_addresses=to_addrs,
                cc_addresses=cc_addrs,
                body_text=body_text,
                body_html=body_html,
                body_html_sanitized=sanitize_html(body_html),
                has_attachments=len(attachments) > 0,
                size_bytes=len(raw_email),
                received_at=datetime.now(UTC),
            )
            db.add(mail)
            synced_count += 1

        await db.flush()

        # Update folder counts
        folder = (
            await db.execute(
                select(MailFolder).where(
                    and_(
                        MailFolder.account_id == account.id,
                        MailFolder.imap_name == "INBOX",
                    )
                )
            )
        ).scalar_one_or_none()
        if folder:
            total = (
                await db.execute(
                    select(text("COUNT(*)")).where(
                        and_(Mail.folder_id == folder.id, Mail.tenant_id == tenant_id)
                    )
                )
            ).scalar()
            unread = (
                await db.execute(
                    select(text("COUNT(*)")).where(
                        and_(
                            Mail.folder_id == folder.id,
                            Mail.tenant_id == tenant_id,
                            not Mail.is_seen,
                        )
                    )
                )
            ).scalar()
            folder.total_count = total
            folder.unread_count = unread
            await db.flush()

        await client.logout()
        return {"synced": synced_count}
    except Exception as e:
        return {"synced": 0, "error": str(e)}


def _compute_thread_id(message_id: str, references: str, in_reply_to: str | None) -> str:
    """Compute thread ID from References/In-Reply-To headers (F-MAIL-05)."""
    ref_parts: list[str] = []
    if references:
        ref_parts = [r.strip() for r in references.split() if r.strip()]
    if in_reply_to and in_reply_to.strip() not in ref_parts:
        ref_parts.append(in_reply_to.strip())
    if ref_parts:
        return ref_parts[0]
    return message_id or str(uuid.uuid4())


# ─── SMTP Send Service (F-MAIL-02) ───


async def send_mail_via_smtp(
    db: AsyncSession,
    *,
    tenant_id: uuid.UUID,
    user_id: uuid.UUID,
    account: MailAccount,
    to_addrs: list[str],
    cc_addrs: list[str] = None,
    bcc_addrs: list[str] = None,
    subject: str = "",
    body_html: str = "",
    body_text: str = "",
    in_reply_to: str | None = None,
    references_header: str | None = None,
    signature: MailSignature | None = None,
) -> dict:
    """Send an email via SMTP using aiosmtplib."""
    cc_addrs = cc_addrs or []
    bcc_addrs = bcc_addrs or []

    # Apply signature if provided
    if signature and signature.body_html:
        body_html = body_html + f"<br><br>{signature.body_html}"
        if body_text:
            body_text = body_text + "\n\n-- \n" + _strip_html(signature.body_html)

    # Build email message
    msg = EmailMessage()
    msg["From"] = formataddr((account.display_name or "", account.email_address))
    msg["To"] = ", ".join(to_addrs)
    if cc_addrs:
        msg["Cc"] = ", ".join(cc_addrs)
    msg["Subject"] = subject
    msg["Date"] = formatdate(localtime=True)
    msg_id = make_msgid(
        domain=account.email_address.split("@")[-1] if "@" in account.email_address else "localhost"
    )
    msg["Message-ID"] = msg_id
    if in_reply_to:
        msg["In-Reply-To"] = in_reply_to
    if references_header:
        msg["References"] = references_header

    if body_html:
        msg.set_content(body_text or _strip_html(body_html), subtype="plain")
        msg.add_alternative(body_html, subtype="html")
    else:
        msg.set_content(body_text, subtype="plain")

    # Send via SMTP
    password = await get_account_password(account)
    try:
        smtp = aiosmtplib.SMTP(
            hostname=account.smtp_host,
            port=account.smtp_port,
            use_tls=account.smtp_tls,
        )
        await smtp.connect()
        await smtp.login(account.username, password)
        recipients = to_addrs + cc_addrs + bcc_addrs
        await smtp.send_message(msg, recipients=recipients)
        await smtp.quit()

        # Store sent mail in Sent folder
        sent_folder = (
            await db.execute(
                select(MailFolder).where(
                    and_(
                        MailFolder.account_id == account.id,
                        MailFolder.imap_name == "Sent",
                    )
                )
            )
        ).scalar_one_or_none()

        if sent_folder:
            thread_id = _compute_thread_id(msg_id, references_header or "", in_reply_to)
            sent_mail = Mail(
                tenant_id=tenant_id,
                account_id=account.id,
                folder_id=sent_folder.id,
                message_id=msg_id,
                thread_id=thread_id,
                in_reply_to=in_reply_to,
                references_header=references_header,
                subject=subject,
                from_address=account.email_address,
                to_addresses=", ".join(to_addrs),
                cc_addresses=", ".join(cc_addrs),
                bcc_addresses=", ".join(bcc_addrs),
                body_text=body_text or _strip_html(body_html),
                body_html=body_html,
                body_html_sanitized=sanitize_html(body_html),
                is_seen=True,
                is_answered=bool(in_reply_to),
                sent_at=datetime.now(UTC),
            )
            db.add(sent_mail)
            await db.flush()

        return {"status": "sent", "message_id": msg_id}
    except Exception as e:
        return {"status": "error", "error": str(e)}


async def reply_to_mail(
    db: AsyncSession,
    *,
    tenant_id: uuid.UUID,
    user_id: uuid.UUID,
    original_mail: Mail,
    account: MailAccount,
    body_html: str,
    body_text: str = "",
    reply_to_all: bool = False,
    signature: MailSignature | None = None,
) -> dict:
    """Reply to a mail, setting In-Reply-To and References headers (F-MAIL-02)."""
    to_addrs = [original_mail.from_address]
    if reply_to_all and original_mail.cc_addresses:
        to_addrs.extend([a.strip() for a in original_mail.cc_addresses.split(",") if a.strip()])

    refs = original_mail.references_header or ""
    new_refs = f"{refs} {original_mail.message_id}".strip()

    result = await send_mail_via_smtp(
        db,
        tenant_id=tenant_id,
        user_id=user_id,
        account=account,
        to_addrs=to_addrs,
        subject=f"Re: {original_mail.subject}".replace("Re: Re: ", "Re: "),
        body_html=body_html,
        body_text=body_text,
        in_reply_to=original_mail.message_id,
        references_header=new_refs,
        signature=signature,
    )

    # Mark original as answered
    original_mail.is_answered = True
    await db.flush()
    return result


async def forward_mail(
    db: AsyncSession,
    *,
    tenant_id: uuid.UUID,
    user_id: uuid.UUID,
    original_mail: Mail,
    account: MailAccount,
    to_addrs: list[str],
    cc_addrs: list[str] = None,
    body_html: str = "",
    body_text: str = "",
    signature: MailSignature | None = None,
) -> dict:
    """Forward a mail with original as forwarded content (F-MAIL-02)."""
    fwd_subject = f"Fwd: {original_mail.subject}".replace("Fwd: Fwd: ", "Fwd: ")
    fwd_body = (
        f"<br><br>----- Original Message -----<br>"
        f"From: {original_mail.from_address}<br>"
        f"Subject: {original_mail.subject}<br><br>"
        f"{original_mail.body_html or original_mail.body_text}"
    )
    full_html = body_html + fwd_body
    full_text = (body_text or _strip_html(body_html)) + "\n\n----- Original Message -----\n"

    result = await send_mail_via_smtp(
        db,
        tenant_id=tenant_id,
        user_id=user_id,
        account=account,
        to_addrs=to_addrs,
        cc_addrs=cc_addrs or [],
        subject=fwd_subject,
        body_html=full_html,
        body_text=full_text,
        signature=signature,
    )

    original_mail.is_forwarded = True
    await db.flush()
    return result


# ─── Template Service (F-MAIL-06) ───


def substitute_template_vars(template_body: str, variables: dict[str, str]) -> str:
    """Replace {{placeholder}} variables in template body."""
    result = template_body
    for key, value in variables.items():
        result = result.replace(f"{{{{{key}}}}}", value)
        result = result.replace(f"{{{{{key.lower()}}}}}", value)
        result = result.replace(f"{{{{{key.upper()}}}}}", value)
    return result


# ─── Mail Rule Engine (F-MAIL-07) ───


def matches_condition(mail: Mail, conditions: dict) -> bool:
    """Check if a mail matches all rule conditions."""
    for field, expected in conditions.items():
        if field == "from_contains":
            if expected.lower() not in mail.from_address.lower():
                return False
        elif field == "subject_contains":
            if expected.lower() not in mail.subject.lower():
                return False
        elif field == "to_contains":
            if expected.lower() not in mail.to_addresses.lower():
                return False
        elif field == "body_contains":
            body = (mail.body_text + mail.body_html).lower()
            if expected.lower() not in body:
                return False
        elif field == "has_attachments":
            if mail.has_attachments != bool(expected):
                return False
        elif field == "is_flagged":
            if mail.is_flagged != bool(expected):
                return False
    return True


async def execute_rule_actions(
    db: AsyncSession, mail: Mail, actions: dict, tenant_id: uuid.UUID
) -> dict:
    """Execute rule actions on a matching mail."""
    results = {}
    for action, value in actions.items():
        if action == "move_to_folder":
            folder_id = uuid.UUID(value) if isinstance(value, str) else value
            folder = (
                await db.execute(
                    select(MailFolder).where(
                        and_(MailFolder.id == folder_id, MailFolder.tenant_id == tenant_id)
                    )
                )
            ).scalar_one_or_none()
            if folder:
                mail.folder_id = folder.id
                results["moved"] = str(folder.id)
        elif action == "label":
            label_id = uuid.UUID(value) if isinstance(value, str) else value
            existing = (
                await db.execute(
                    select(MailLabelAssignment).where(
                        and_(
                            MailLabelAssignment.mail_id == mail.id,
                            MailLabelAssignment.label_id == label_id,
                        )
                    )
                )
            ).scalar_one_or_none()
            if not existing:
                assignment = MailLabelAssignment(
                    tenant_id=tenant_id,
                    mail_id=mail.id,
                    label_id=label_id,
                )
                db.add(assignment)
                results["labeled"] = str(label_id)
        elif action == "mark_seen":
            mail.is_seen = bool(value)
            results["seen"] = bool(value)
        elif action == "mark_flagged":
            mail.is_flagged = bool(value)
            results["flagged"] = bool(value)
        elif action == "forward_to":
            results["forward_to"] = value
    await db.flush()
    return results


async def apply_rules_to_mail(db: AsyncSession, mail: Mail, tenant_id: uuid.UUID) -> list[dict]:
    """Find and apply all matching rules to a mail, sorted by priority."""
    rules = (
        (
            await db.execute(
                select(MailRule)
                .where(
                    and_(
                        MailRule.tenant_id == tenant_id,
                        MailRule.is_active,
                        or_(
                            MailRule.account_id == mail.account_id,
                            MailRule.account_id.is_(None),
                        ),
                    )
                )
                .order_by(MailRule.priority)
            )
        )
        .scalars()
        .all()
    )

    applied = []
    for rule in rules:
        conditions = json.loads(rule.conditions) if rule.conditions else {}
        actions = json.loads(rule.actions) if rule.actions else {}
        if matches_condition(mail, conditions):
            result = await execute_rule_actions(db, mail, actions, tenant_id)
            applied.append({"rule_id": str(rule.id), "rule_name": rule.name, "actions": result})
    return applied


# ─── Vacation Auto-Reply (F-MAIL-08) ───


VACATION_DEDUP_HOURS = 24


async def should_send_vacation_reply(
    db: AsyncSession,
    account_id: uuid.UUID,
    sender_address: str,
    tenant_id: uuid.UUID,
) -> bool:
    """Check if vacation auto-reply should be sent (dedup within 24h)."""
    cutoff = datetime.now(UTC) - timedelta(hours=VACATION_DEDUP_HOURS)
    existing = (
        await db.execute(
            select(VacationSentLog).where(
                and_(
                    VacationSentLog.account_id == account_id,
                    VacationSentLog.sender_address == sender_address,
                    VacationSentLog.sent_at >= cutoff,
                    VacationSentLog.tenant_id == tenant_id,
                )
            )
        )
    ).scalar_one_or_none()
    return existing is None


async def log_vacation_sent(
    db: AsyncSession,
    account_id: uuid.UUID,
    sender_address: str,
    tenant_id: uuid.UUID,
) -> None:
    """Log that a vacation auto-reply was sent to a sender."""
    log = VacationSentLog(
        tenant_id=tenant_id,
        account_id=account_id,
        sender_address=sender_address,
        sent_at=datetime.now(UTC),
    )
    db.add(log)
    await db.flush()


# ─── PGP Service (F-MAIL-12) ───


def import_pgp_private_key(private_key_armored: str, passphrase: str = "") -> tuple[str, str]:
    """Import a PGP private key. Returns (key_id, public_key_armored)."""
    key, _ = pgpy.PGPKey.from_blob(private_key_armored)
    if key.is_protected:
        with key.unlock(passphrase):
            pub_key = key.pubkey
            key_id = str(key.fingerprint).upper()[-16:]
            return key_id, str(pub_key)
    pub_key = key.pubkey
    key_id = str(key.fingerprint).upper()[-16:]
    return key_id, str(pub_key)


def import_pgp_public_key(public_key_armored: str) -> str:
    """Import a PGP public key. Returns key_id."""
    key, _ = pgpy.PGPKey.from_blob(public_key_armored)
    return str(key.fingerprint).upper()[-16:]


def pgp_encrypt_message(plaintext: str, recipient_public_key_armored: str) -> str:
    """Encrypt a message with recipient's public PGP key."""
    pub_key, _ = pgpy.PGPKey.from_blob(recipient_public_key_armored)
    msg = pgpy.PGPMessage.new(plaintext)
    encrypted = pub_key.encrypt(msg)
    return str(encrypted)


def pgp_decrypt_message(ciphertext: str, private_key_armored: str, passphrase: str = "") -> str:
    """Decrypt a PGP-encrypted message."""
    key, _ = pgpy.PGPKey.from_blob(private_key_armored)
    enc_msg = pgpy.PGPMessage.from_blob(ciphertext)
    if key.is_protected:
        with key.unlock(passphrase):
            decrypted = key.decrypt(enc_msg)
            return decrypted.message.decode("utf-8")
    decrypted = key.decrypt(enc_msg)
    return decrypted.message.decode("utf-8")


# ─── Contact Linking (F-MAIL-10) ───


def extract_email_addresses(text: str) -> list[str]:
    """Extract email addresses from a text string."""
    if not text:
        return []
    return re.findall(r"[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}", text)


# ─── Utility ───


def _strip_html(html: str) -> str:
    """Simple HTML to text conversion for plain text fallback."""
    if not html:
        return ""
    # Remove tags
    text = re.sub(r"<[^>]+>", "", html)
    # Replace HTML entities
    text = (
        text.replace("&nbsp;", " ")
        .replace("&amp;", "&")
        .replace("&lt;", "<")
        .replace("&gt;", ">")
        .replace("&quot;", '"')
    )
    return text.strip()


def mail_to_response(
    mail: Mail,
    attachments: list[MailAttachment] | None = None,
    labels: list[MailLabel] | None = None,
) -> dict:
    """Convert a Mail ORM object to a response dict."""
    resp = {
        "id": str(mail.id),
        "account_id": str(mail.account_id),
        "folder_id": str(mail.folder_id),
        "message_id": mail.message_id,
        "thread_id": mail.thread_id,
        "in_reply_to": mail.in_reply_to,
        "subject": mail.subject,
        "from_address": mail.from_address,
        "from_name": mail.from_address.split("<")[0].strip().strip('"') if "<" in mail.from_address else mail.from_address,
        "to_addresses": extract_email_addresses(mail.to_addresses) if mail.to_addresses else [],
        "cc_addresses": extract_email_addresses(mail.cc_addresses) if mail.cc_addresses else [],
        "bcc_addresses": extract_email_addresses(mail.bcc_addresses) if mail.bcc_addresses else [],
        "body_text": mail.body_text,
        "body_html": mail.body_html if mail.body_html else None,
        "body_html_sanitized": mail.body_html_sanitized,
        "sanitized_html": mail.body_html_sanitized,
        "date": mail.received_at.isoformat() if mail.received_at else (mail.sent_at.isoformat() if mail.sent_at else None),
        "is_seen": mail.is_seen,
        "is_flagged": mail.is_flagged,
        "is_draft": mail.is_draft,
        "is_answered": mail.is_answered,
        "is_forwarded": mail.is_forwarded,
        "has_attachments": mail.has_attachments,
        "size_bytes": mail.size_bytes,
        "received_at": mail.received_at,
        "sent_at": mail.sent_at,
        "contact_id": str(mail.contact_id) if mail.contact_id else None,
        "company_id": str(mail.company_id) if mail.company_id else None,
        "attachments": [],
        "labels": [],
    }
    if attachments:
        resp["attachments"] = [
            {
                "id": str(a.id),
                "filename": a.filename,
                "mime_type": a.mime_type,
                "size_bytes": a.size_bytes,
                "dms_file_id": str(a.dms_file_id) if a.dms_file_id else None,
            }
            for a in attachments
        ]
    if labels:
        resp["labels"] = [
            {"id": str(lbl.id), "name": lbl.name, "color": lbl.color} for lbl in labels
        ]
    return resp


def folder_to_response(folder: MailFolder) -> dict:
    """Convert MailFolder to response dict."""
    return {
        "id": str(folder.id),
        "account_id": str(folder.account_id),
        "name": folder.name,
        "imap_name": folder.imap_name,
        "parent_id": str(folder.parent_id) if folder.parent_id else None,
        "is_standard": folder.is_standard,
        "unread_count": folder.unread_count,
        "total_count": folder.total_count,
    }


def rule_to_response(rule: MailRule) -> dict:
    """Convert MailRule to response dict."""
    return {
        "id": str(rule.id),
        "name": rule.name,
        "account_id": str(rule.account_id) if rule.account_id else None,
        "priority": rule.priority,
        "is_active": rule.is_active,
        "conditions": json.loads(rule.conditions) if rule.conditions else {},
        "actions": json.loads(rule.actions) if rule.actions else {},
    }


def template_to_response(template: MailTemplate) -> dict:
    """Convert MailTemplate to response dict."""
    return {
        "id": str(template.id),
        "name": template.name,
        "subject": template.subject,
        "body_html": template.body_html,
    }


def signature_to_response(sig: MailSignature) -> dict:
    """Convert MailSignature to response dict."""
    return {
        "id": str(sig.id),
        "name": sig.name,
        "body_html": sig.body_html,
        "account_id": str(sig.account_id) if sig.account_id else None,
        "is_default": sig.is_default,
    }


def label_to_response(label: MailLabel) -> dict:
    """Convert MailLabel to response dict."""
    return {
        "id": str(label.id),
        "name": label.name,
        "color": label.color,
    }