from __future__ import annotations

from fastapi import APIRouter, Depends, HTTPException, status
from sqlalchemy.orm import Session

from ..db import get_db
from ..models import Case, KnownDog, Match, UnknownDog, User
from ..models.base import (
    CaseStatus,
    CaseType,
    KnownDogStatus,
    MatchStatus,
    SubjectType,
    UnknownDogStatus,
)
from ..schemas.case import MatchOut, ReclaimContact, ReclaimInfo
from ..security import get_current_user
from .helpers import pictures_for
from .hydrate import build_match_out
from .shelters import nearby_shelters

router = APIRouter(prefix="/matches", tags=["matches"])


def _load_owned_match(db: Session, match_id: int, user: User) -> tuple[Match, Case]:
    match = db.get(Match, match_id)
    if not match:
        raise HTTPException(status.HTTP_404_NOT_FOUND, "Match not found")
    case = db.get(Case, match.case_id)
    if not case:
        raise HTTPException(status.HTTP_404_NOT_FOUND, "Case not found")
    if case.person_id != user.id and user.role.value != "admin":
        raise HTTPException(status.HTTP_403_FORBIDDEN, "Not your match")
    return match, case


@router.post("/{match_id}/confirm", response_model=MatchOut)
def confirm_match(
    match_id: int,
    user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
) -> MatchOut:
    match, case = _load_owned_match(db, match_id, user)
    # Once resolved/closed a match is already confirmed — don't let a different dog be matched.
    if case.status in (CaseStatus.resolved, CaseStatus.closed) and match.status != MatchStatus.confirmed:
        raise HTTPException(
            status.HTTP_400_BAD_REQUEST, "This case is already resolved."
        )
    match.status = MatchStatus.confirmed
    match.reviewed = True
    match.reviewed_by = user.id

    # A confirmed match drives both involved cases/dogs toward resolution (spec §1, §9.3).
    case.status = CaseStatus.resolved
    if match.candidate_type == SubjectType.unknown:
        dog = db.get(UnknownDog, match.candidate_id)
        if dog:
            dog.status = UnknownDogStatus.reunited
        if case.known_dog_id:
            known = db.get(KnownDog, case.known_dog_id)
            if known:
                known.status = KnownDogStatus.reunited
    else:
        known = db.get(KnownDog, match.candidate_id)
        if known:
            known.status = KnownDogStatus.reunited
        if case.unknown_dog_id:
            unknown = db.get(UnknownDog, case.unknown_dog_id)
            if unknown:
                unknown.status = UnknownDogStatus.reunited

    if match.candidate_case_id:
        other = db.get(Case, match.candidate_case_id)
        if other:
            other.status = CaseStatus.resolved

    db.commit()
    db.refresh(match)
    return build_match_out(db, match)


@router.get("/{match_id}/reclaim", response_model=ReclaimInfo)
def match_reclaim(
    match_id: int,
    user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
) -> ReclaimInfo:
    """After confirming a match, tell the owner where their dog is now and how to go get it.

    Finder contact is only revealed once the match is confirmed (spec §11 mediated contact); a
    shelter/vet location is public either way.
    """
    match, case = _load_owned_match(db, match_id, user)
    if match.status != MatchStatus.confirmed:
        raise HTTPException(
            status.HTTP_400_BAD_REQUEST, "Confirm the match before viewing reclaim details."
        )

    # Resolve the found (unknown) dog + the found case that reported it.
    found_dog = found_case = None
    if match.candidate_type == SubjectType.unknown:
        found_dog = db.get(UnknownDog, match.candidate_id)
        if match.candidate_case_id:
            found_case = db.get(Case, match.candidate_case_id)
    elif case.unknown_dog_id:  # owner is the finder confirming their own found case
        found_dog = db.get(UnknownDog, case.unknown_dog_id)
        found_case = case

    # The owner's own (known) dog — name + photos for side-by-side verification.
    known_id = case.known_dog_id if case.type == CaseType.lost else (
        match.candidate_id if match.candidate_type == SubjectType.known else None
    )
    your_dog_name = None
    your_photos: list[dict] = []
    if known_id:
        kd = db.get(KnownDog, known_id)
        your_dog_name = kd.name if kd else None
        your_photos = [p.model_dump() for p in pictures_for(db, SubjectType.known, known_id)]

    if not found_dog:
        return ReclaimInfo(
            match_id=match.id, match_status=match.status,
            your_dog_name=your_dog_name, your_photos=your_photos, found=False, held_at="unknown",
        )

    at_shelter = (
        found_dog.status == UnknownDogStatus.at_shelter or bool(found_dog.current_location_detail)
    )
    zip_ = found_dog.current_zip or (found_case.event_zip if found_case else None)

    contact = None
    if not at_shelter and found_case and (
        found_case.finder_name or found_case.finder_email or found_case.finder_phone
    ):
        contact = ReclaimContact(
            name=found_case.finder_name,
            email=found_case.finder_email,
            phone=found_case.finder_phone,
        )

    return ReclaimInfo(
        match_id=match.id,
        match_status=match.status,
        your_dog_name=your_dog_name,
        your_photos=your_photos,
        found=True,
        held_at="shelter_or_vet" if at_shelter else "finder_custody",
        location_name=found_dog.current_location_detail,
        current_zip=zip_,
        current_location=found_case.current_location if found_case else None,
        found_date=found_case.event_date if found_case else None,
        contact=contact,
        photos=[p.model_dump() for p in pictures_for(db, SubjectType.unknown, found_dog.id)],
        nearby_shelters=nearby_shelters(zip_),
    )


@router.post("/{match_id}/reject", response_model=MatchOut)
def reject_match(
    match_id: int,
    user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
) -> MatchOut:
    match, _ = _load_owned_match(db, match_id, user)
    match.status = MatchStatus.rejected
    match.reviewed = True
    match.reviewed_by = user.id
    db.commit()
    db.refresh(match)
    return build_match_out(db, match)


@router.post("/{match_id}/reconsider", response_model=MatchOut)
def reconsider_match(
    match_id: int,
    user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
) -> MatchOut:
    """Move a "not a match" back to a pending candidate so the owner can review it again."""
    match, case = _load_owned_match(db, match_id, user)
    if case.status in (CaseStatus.resolved, CaseStatus.closed):
        raise HTTPException(status.HTTP_400_BAD_REQUEST, "This case is already resolved.")
    if match.status != MatchStatus.rejected:
        raise HTTPException(status.HTTP_400_BAD_REQUEST, "Only rejected matches can be reconsidered.")
    match.status = MatchStatus.pending
    match.reviewed = False
    match.reviewed_by = None
    db.commit()
    db.refresh(match)
    return build_match_out(db, match)