import logging
import os
import uuid
from datetime import datetime, timezone
from typing import Any, List, Optional

from dotenv import load_dotenv
from fastapi import HTTPException
from inbox.enums import Candidate_application_Status
from role.models import EnumRoles, Roles
from sqlalchemy import Column, DateTime, func, or_, update
from sqlalchemy.dialects.postgresql import JSONB
from sqlalchemy.exc import IntegrityError
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy.orm import selectinload
from sqlmodel import Field, Relationship, SQLModel, select, true

from job.candidate.models import Activity, Feedback, Interviews
from users.models import Users
from users.plugins import hash_password

load_dotenv()
logger = logging.getLogger("inbox.models")

# Placeholder only. The account lands inactive and the candidate is mailed a
# confirmation link; the real password comes from the reset flow afterwards.
DEFAULT_CANDIDATE_PASSWORD = os.getenv("DEFAULT_CANDIDATE_PASSWORD", "Utopia!@#")
CANDIDATE_ROLE_ID_FALLBACK = 8          # mirrors users/views.py:signup_user
SKIP_SENDER_PREFIXES = ("noreply", "no-reply", "donotreply", "do-not-reply",
                        "mailer-daemon", "postmaster", "bounce")


class Inbox(SQLModel, table=True):
    __tablename__ = "inbox"

    id: int | None = Field(default=None, primary_key=True)
    user_id: uuid.UUID | None = Field(default=None, foreign_key="users.id")

    alert_id: uuid.UUID | None = Field(default=None, foreign_key="inbox_alerts.id")
    alerts: Optional["Inbox_Alerts"] = Relationship(back_populates="inbox")

    message_id: uuid.UUID | None = Field(default=None, foreign_key="inbox_messages.id")
    messages: Optional["Inbox_Messages"] = Relationship(back_populates="inbox")

    created_at: datetime = Field(default_factory=datetime.now)
    updated_at: datetime = Field(default_factory=datetime.now)

    favorite: Optional[bool] = Field(default=False)
    rating: Optional[float] = Field(default=0.0)

    # selectin on one-to-many: joined would repeat the inbox row per child
    interviews: List["Interviews"] = Relationship(
        back_populates="inbox",
        sa_relationship_kwargs={"lazy": "selectin"},
    )
    activity: List["Activity"] = Relationship(
        back_populates="inbox",
        sa_relationship_kwargs={"lazy": "selectin"},
    )
    feedback: List["Feedback"] = Relationship(
        back_populates="inbox",
        sa_relationship_kwargs={"lazy": "selectin"},
    )
    user: Optional["Users"] = Relationship(
        back_populates="inbox",
        sa_relationship_kwargs={"lazy": "joined"},
    )

    @classmethod
    def _candidate_search_filter(cls, search: str):
        pattern = f"%{search}%"
        return or_(Users.name.ilike(pattern), Users.email.ilike(pattern))

    @classmethod
    async def get_candidate_profile(cls,session:AsyncSession,user_id:uuid.UUID|None=None,limit:int=10,offset:int=0,search:str|None=None):
        try:
            options=[selectinload(cls.messages)]
            if user_id:
                options.extend([
                    selectinload(cls.interviews),
                    selectinload(cls.activity),
                    selectinload(cls.feedback),
                ])
            qry = (
                select(cls)
                .options(*options)
                .join(Users, cls.user_id == Users.id)
                .join(Roles, Users.role_id == Roles.id)
                .where(Roles.role_name == EnumRoles.CANDIDATE.value)
            )
            if user_id:
                qry = qry.where(cls.user_id == user_id)
            if search:
                qry = qry.where(cls._candidate_search_filter(search))
            qry = qry.limit(limit).offset(offset)
            result = await session.execute(qry)
            rows = result.scalars().all()
            if user_id and len(rows) == 1:
                return rows[0]
            return rows
        except Exception as e:
            raise HTTPException(status_code=500,detail=str(e))

    @classmethod
    async def count_candidate_profiles(cls,session:AsyncSession,user_id:uuid.UUID|None=None,search:str|None=None):
        """Result-set size for the same predicate get_candidate_profile pages over."""
        try:
            qry = (
                select(func.count())
                .select_from(cls)
                .join(Users, cls.user_id == Users.id)
                .join(Roles, Users.role_id == Roles.id)
                .where(Roles.role_name == EnumRoles.CANDIDATE.value)
            )
            if user_id:
                qry = qry.where(cls.user_id == user_id)
            if search:
                qry = qry.where(cls._candidate_search_filter(search))
            result = await session.execute(qry)
            return result.scalar_one()
        except Exception as e:
            raise HTTPException(status_code=500,detail=str(e))

    @classmethod
    async def get_inbox_by_id(cls,session:AsyncSession,record_id:int|str|None):
        if record_id is None:
            return None
        try:
            iid=int(record_id)
        except (TypeError,ValueError):
            return None
        result=await session.execute(select(cls).where(cls.id==iid))
        return result.scalars().first()

    @classmethod
    async def get_inbox_by_message_id(cls,session:AsyncSession,message_id):
        try:
            mid=uuid.UUID(str(message_id))
        except ValueError:
            return None
        result=await session.execute(
            select(cls).where(cls.message_id==mid).order_by(cls.created_at.desc())
        )
        return result.scalars().first()

    @classmethod
    async def get_inbox_by_user_id(cls,session:AsyncSession,user_id):
        try:
            uid=uuid.UUID(str(user_id))
        except ValueError:
            return None
        result=await session.execute(
            select(cls).where(cls.user_id==uid).order_by(cls.created_at.desc())
        )
        return result.scalars().first()

    @classmethod
    async def update_inbox(cls,session:AsyncSession,record_id,fields:dict):
        row=await cls.get_inbox_by_id(session,record_id)
        if not row:
            return None
        for key,value in fields.items():
            setattr(row,key,value)
        row.updated_at=datetime.now()
        session.add(row)
        await session.commit()
        await session.refresh(row)
        return row


class Inbox_Alerts(SQLModel, table=True):
    __tablename__ = "inbox_alerts"

    id: uuid.UUID = Field(default_factory=uuid.uuid4, primary_key=True)
    alert_sender_name: str
    alert_sender_email: str
    is_read: bool = Field(default=False)
    recieve_time: datetime = Field(default_factory=datetime.now)

    inbox: list[Inbox] = Relationship(back_populates="alerts")


class Inbox_Messages(SQLModel, table=True):
    __tablename__ = "inbox_messages"

    id: uuid.UUID = Field(default_factory=uuid.uuid4, primary_key=True)
    message_id: str | None = Field(default=None, index=True, unique=True)
    full_email_response: dict[str, Any] | None = Field(
        default=None, sa_column=Column(JSONB)
    )
    application_status: Candidate_application_Status = Field(default=Candidate_application_Status.CLOSED)
    message_subject: str
    message_body: str
    message_sent_time: str
    message_received_time: str
    message_from: str
    message_to: str
    message_cc: str | None = Field(default=None)
    message_bcc: str | None = Field(default=None)
    message_read: bool = Field(default=False)
    attachment: bool = Field(default=False)
    message_reply: str | None = Field(default=None)
    file_name: str | None = Field(default=None)
    file_path: str | None = Field(default=None)
    resume_text: str | None = Field(default=None)
    experience: str | None = Field(default=None)
    suggested_job_post_ids: list[str] | None = Field(default=None, sa_column=Column(JSONB))
    assigned_job_post_id: uuid.UUID | None = Field(default=None, foreign_key="job_posts.id", index=True)

    match_summary: str | None = Field(default=None)
    match_reasoning: str | None = Field(default=None)
    match_status: str | None = Field(default=None)
    match_error: str | None = Field(default=None)
    matched_at: datetime | None = Field(default=None, sa_type=DateTime(timezone=True))
    candidate_phone_number: str | None = Field(default="xxx-xxx-xxxx")
    candidate_education: str | None = Field(default=None)
    current_employment: str | None = Field(default=None)    
    inbox: list[Inbox] = Relationship(back_populates="messages")

    @staticmethod
    def _body_text(email_data: dict) -> str:
        body = email_data.get("body")
        if isinstance(body, dict):
            return body.get("content") or ""
        if isinstance(body, str):
            return body
        return email_data.get("bodyPreview") or ""


    @classmethod
    async def get_all_applications(cls,session:AsyncSession,message_id:uuid.UUID|int|None=None):
        try:
            qry=select(cls.message_id,cls.full_email_response,cls.message_subject,cls.message_from,cls.message_to,cls.message_sent_time,cls.message_read,cls.attachment)
            if message_id:
                qry=qry.where(cls.message_id==message_id)
            result=await session.execute(qry)
            return result.scalars().all()

        except Exception as e:
            raise HTTPException(status_code=500,detail=str(e))
    @classmethod
    async def set_match_result(
        cls,
        session: AsyncSession,
        record_id,
        *,
        resume_text=None,
        experience=None,
        candidate_education=None,
        candidate_phone_number=None,
        current_employment=None,
        suggested_job_post_ids=None,
        summary="",
        reasoning="",
        status="",
        error="",
    ):
        """Persist agent output onto one inbox row; returns the row or None."""
        row = await cls.get_inbox_message_by_id(session, record_id)
        if not row:
            return None
        if resume_text is not None:
            row.resume_text = resume_text
        if candidate_phone_number is not None:
            row.candidate_phone_number = candidate_phone_number
        if candidate_education is not None:
            row.candidate_education = candidate_education
        if current_employment is not None:
            row.current_employment = current_employment
        row.suggested_job_post_ids = suggested_job_post_ids
        row.match_summary = summary or None
        row.match_reasoning = reasoning or None
        row.match_status = status or None
        row.match_error = error or None
        row.experience = experience or None
        row.matched_at = datetime.now(timezone.utc)
        session.add(row)
        await session.commit()
        await session.refresh(row)
        return row

    @classmethod
    def _fields_from_email(cls, email_data: dict, file_path: list[str] | None = None) -> dict:
        return {
            "message_subject": email_data.get("subject") or "",
            "message_body": cls._body_text(email_data),
            "message_sent_time": email_data.get("sentDateTime") or "",
            "message_read": bool(email_data.get("isRead")),
            "message_received_time": email_data.get("receivedDateTime") or "",
            "message_from": email_data.get("from", {})
            .get("emailAddress", {})
            .get("address", ""),
            "message_to": ",".join(
                [r["emailAddress"]["address"] for r in email_data.get("toRecipients", [])]
            ),
            "message_cc": ",".join(
                [r["emailAddress"]["address"] for r in email_data.get("ccRecipients", [])]
            ),
            "message_bcc": ",".join(
                [r["emailAddress"]["address"] for r in email_data.get("bccRecipients", [])]
            ),
            "attachment": bool(email_data.get("hasAttachments")),
            "message_reply": ",".join(
                [r["emailAddress"]["address"] for r in email_data.get("replyTo", [])]
            ),
            "message_id": email_data.get("id"),
            "file_name": ",".join(
                [r.get("name") for r in email_data.get("attachments", [])]
            ),
            "file_path": ",".join(file_path) if file_path else None,
            "full_email_response": email_data,
        }

    @classmethod
    def _sender_address(cls, email_data: dict) -> str:
        return (
            email_data.get("from", {})
            .get("emailAddress", {})
            .get("address", "")
            or ""
        ).strip().lower()

    @classmethod
    def _sender_display_name(cls, email_data: dict, address: str) -> str:
        name = (
            email_data.get("from", {})
            .get("emailAddress", {})
            .get("name")
            or ""
        ).strip()
        if name:
            return name
        return address.split("@", 1)[0] if address else "candidate"

    @classmethod
    def _is_linkable_sender(cls, address: str) -> bool:
        if not address or "@" not in address:
            return False
        local = address.split("@", 1)[0]
        return not local.startswith(SKIP_SENDER_PREFIXES)

    @classmethod
    async def _link_sender(cls,session:AsyncSession,email_data:dict,email):
        address=cls._sender_address(email_data)
        if not cls._is_linkable_sender(address):
            return None
        try:
            # id-only: avoid Users.job_posts selectin / role lazy loads under asyncio
            user_id=(await session.execute(
                select(Users.id).where(func.lower(Users.email)==address)
            )).scalar_one_or_none()

            if user_id is None:
                role=await Roles.get_role_by_name(session,EnumRoles.CANDIDATE.value)
                user=Users(
                    name=cls._sender_display_name(email_data,address),
                    email=address,
                    role_id=role.id if role else CANDIDATE_ROLE_ID_FALLBACK,
                    password=hash_password(DEFAULT_CANDIDATE_PASSWORD),
                )
                session.add(user)
                # autoflush=False: flush so users.id exists before inbox FK insert
                # (Relationship helps ordering, but flush keeps this path explicit).
                await session.flush()
                session.add(Inbox(user_id=user.id,message_id=email.id))
                await session.commit()
                return address

            link=(await session.execute(
                select(Inbox.id).where(Inbox.message_id==email.id,Inbox.user_id==user_id)
            )).scalar_one_or_none()
            if link is None:
                session.add(Inbox(user_id=user_id,message_id=email.id))
                await session.commit()
            return None
        except IntegrityError:
            await session.rollback()
            return None
        except Exception as e:
            await session.rollback()
            logger.warning("sender link failed for %s: %s",address,e)
            return None

    @classmethod
    async def insert_email(
        cls,
        session: AsyncSession,
        email_data: dict,
        file_path: list[str] | None = None,
    ):
        """Returns (row, new_user_email). new_user_email is set only when this call
        created the sender's Users row."""
        fields = cls._fields_from_email(email_data, file_path)
        external_id = fields.get("message_id")
        link_user=None
        if external_id:
            existing = (
                await session.execute(
                    select(cls).where(cls.message_id == external_id)
                )
            ).scalars().first()
            if existing:
                for key, value in fields.items():
                    setattr(existing, key, value)
                session.add(existing)
                await session.commit()
                await session.refresh(existing)

                if fields.get("attachment"):
                    link_user=await cls._link_sender(session, email_data, existing)
                    # _link_sender may rollback (IntegrityError); that expires this row
                    await session.refresh(existing)
                return existing, link_user

        email = cls(**fields)
        session.add(email)
        await session.commit()
        await session.refresh(email)

        if fields.get("attachment"):
            link_user=await cls._link_sender(session, email_data, email)
            await session.refresh(email)
        return email, link_user

    @classmethod
    def _search_filter(cls, search: str):
        pattern = f"%{search}%"
        return or_(
            cls.message_subject.ilike(pattern),
            cls.message_from.ilike(pattern),
            cls.message_body.ilike(pattern),
        )

    @classmethod
    async def get_inbox_messages(
        cls, session: AsyncSession, top: int | None, skip: int, search: str | None, isread: bool=True, application_status: Candidate_application_Status=Candidate_application_Status.CLOSED, assigned: bool | None=None
    ):
        statement = select(cls).order_by(cls.message_received_time.desc())
        if search:
            statement = statement.where(cls._search_filter(search))

        if application_status == Candidate_application_Status.PROCESS or application_status==Candidate_application_Status.REJECTED:
            statement = statement.where(cls.application_status==application_status)

        if assigned is True:
            statement = statement.where(cls.assigned_job_post_id.is_not(None))
        elif assigned is False:
            statement = statement.where(cls.assigned_job_post_id.is_(None))

        if skip:
            statement = statement.offset(skip)

        if top is not None:
            statement = statement.limit(top)

        if isread==False:
            statement = statement.where(cls.message_read==False)
        result = await session.execute(statement)
        return result.scalars().all()

    @classmethod
    async def get_inbox_message_by_id(cls, session: AsyncSession, record_id: str):
        try:
            uid = uuid.UUID(str(record_id))
        except ValueError:
            return None
        result = await session.execute(select(cls).where(cls.id == uid))
        return result.scalars().first()

    @classmethod
    async def set_assigned_job_post(cls, session: AsyncSession, record_id, job_post_id):
        """Set or clear assigned_job_post_id; returns the row or None if missing."""
        row = await cls.get_inbox_message_by_id(session, record_id)
        if not row:
            return None
        if job_post_id is None:
            row.assigned_job_post_id = None
        else:
            try:
                row.assigned_job_post_id = uuid.UUID(str(job_post_id))
            except ValueError:
                return None
        session.add(row)
        await session.commit()
        await session.refresh(row)
        return row

    @classmethod
    async def count_inbox_messages(cls, session: AsyncSession, search: str | None, isread: bool=True, application_status: Candidate_application_Status=Candidate_application_Status.CLOSED, assigned: bool | None=None):
        statement = select(func.count()).select_from(cls)
        if search:
            statement = statement.where(cls._search_filter(search))
        if application_status == Candidate_application_Status.PROCESS or application_status==Candidate_application_Status.REJECTED:
            statement = statement.where(cls.application_status==application_status)
        if assigned is True:
            statement = statement.where(cls.assigned_job_post_id.is_not(None))
        elif assigned is False:
            statement = statement.where(cls.assigned_job_post_id.is_(None))
        if isread==False:
            statement = statement.where(cls.message_read==False)
        result = await session.execute(statement)
        return result.scalar_one()

    @classmethod
    async def apply_read_status(cls, session: AsyncSession, changes) -> int:
        """[{id, isRead, ...}] -> bulk UPDATE message_read. Returns rows touched.

        read is a ONE-WAY LATCH: only false -> true is applied, never the reverse.
        mark_message_read writes the local column only — nothing pushes the state
        back to Outlook — so upstream keeps reporting isRead=false and the
        every-minute sync_read_status sweep would otherwise revert a mail the user
        just opened. Cost of the latch: un-reading a mail in Outlook no longer
        propagates here.
        """
        if not changes:
            return 0
        read_ids=[c.get("id") for c in changes if c.get("id") and c.get("isRead")]
        if not read_ids:
            return 0
        result=await session.execute(
            update(cls).where(cls.message_id.in_(read_ids)).values(message_read=True)
        )
        await session.commit()
        return result.rowcount or 0

    @classmethod
    async def mark_message_read(cls, session: AsyncSession, record_id):
        row=await cls.get_inbox_message_by_id(session,record_id)
        if not row:
            return None
        row.message_read=True
        session.add(row)
        await session.commit()
        await session.refresh(row)
        return row