"""HR-панель и административные действия."""

from __future__ import annotations

from fastapi import APIRouter, Depends, HTTPException, status
from sqlalchemy import func
from sqlalchemy.exc import NoResultFound
from sqlalchemy.orm import Session, selectinload

from app.api.deps import require_hr
from app.db.session import get_db
from app.models.artifact import Artifact
from app.models.branch import Branch, BranchMission
from app.models.mission import (
    Mission,
    MissionCompetencyReward,
    MissionPrerequisite,
    MissionSubmission,
    SubmissionStatus,
)
from app.models.rank import Rank, RankCompetencyRequirement, RankMissionRequirement
from app.models.user import Competency, User, UserRole
from app.schemas.artifact import ArtifactCreate, ArtifactRead, ArtifactUpdate
from app.schemas.branch import BranchCreate, BranchMissionRead, BranchRead, BranchUpdate
from app.schemas.mission import (
    MissionBase,
    MissionCreate,
    MissionDetail,
    MissionSubmissionRead,
    MissionUpdate,
)
from app.schemas.rank import (
    RankBase,
    RankCreate,
    RankDetailed,
    RankRequirementCompetency,
    RankRequirementMission,
    RankUpdate,
)
from app.schemas.user import CompetencyBase
from app.services.mission import approve_submission, reject_submission
from app.schemas.admin_stats import AdminDashboardStats, BranchCompletionStat, SubmissionStats

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


def _mission_to_detail(mission: Mission) -> MissionDetail:
    """Формируем детальную схему миссии."""

    return MissionDetail(
        id=mission.id,
        title=mission.title,
        description=mission.description,
        xp_reward=mission.xp_reward,
        mana_reward=mission.mana_reward,
        difficulty=mission.difficulty,
        is_active=mission.is_active,
        minimum_rank_id=mission.minimum_rank_id,
        artifact_id=mission.artifact_id,
        prerequisites=[link.required_mission_id for link in mission.prerequisites],
        competency_rewards=[
            {
                "competency_id": reward.competency_id,
                "competency_name": reward.competency.name,
                "level_delta": reward.level_delta,
            }
            for reward in mission.competency_rewards
        ],
        created_at=mission.created_at,
        updated_at=mission.updated_at,
    )


def _rank_to_detailed(rank: Rank) -> RankDetailed:
    """Формируем ранг со списком требований."""

    return RankDetailed(
        id=rank.id,
        title=rank.title,
        description=rank.description,
        required_xp=rank.required_xp,
        mission_requirements=[
            RankRequirementMission(mission_id=req.mission_id, mission_title=req.mission.title)
            for req in rank.mission_requirements
        ],
        competency_requirements=[
            RankRequirementCompetency(
                competency_id=req.competency_id,
                competency_name=req.competency.name,
                required_level=req.required_level,
            )
            for req in rank.competency_requirements
        ],
        created_at=rank.created_at,
        updated_at=rank.updated_at,
    )


def _branch_to_read(branch: Branch) -> BranchRead:
    """Формируем схему ветки с отсортированными миссиями."""

    missions = sorted(branch.missions, key=lambda item: item.order)
    return BranchRead(
        id=branch.id,
        title=branch.title,
        description=branch.description,
        category=branch.category,
        missions=[
            BranchMissionRead(
                mission_id=item.mission_id,
                mission_title=item.mission.title if item.mission else "",
                order=item.order,
                is_completed=False,
                is_available=True,
            )
            for item in missions
        ],
        total_missions=len(missions),
        completed_missions=0,
    )


def _load_rank(db: Session, rank_id: int) -> Rank:
    """Загружаем ранг с зависимостями."""

    return (
        db.query(Rank)
        .options(
            selectinload(Rank.mission_requirements).selectinload(RankMissionRequirement.mission),
            selectinload(Rank.competency_requirements).selectinload(RankCompetencyRequirement.competency),
        )
        .filter(Rank.id == rank_id)
        .one()
    )


def _load_mission(db: Session, mission_id: int) -> Mission:
    """Загружаем миссию с зависимостями."""

    return (
        db.query(Mission)
        .options(
            selectinload(Mission.prerequisites),
            selectinload(Mission.competency_rewards).selectinload(MissionCompetencyReward.competency),
            selectinload(Mission.branches),
        )
        .filter(Mission.id == mission_id)
        .one()
    )


@router.get("/missions", response_model=list[MissionBase], summary="Миссии (HR)")
def admin_missions(*, db: Session = Depends(get_db), current_user=Depends(require_hr)) -> list[MissionBase]:
    """Список всех миссий для HR."""

    missions = db.query(Mission).order_by(Mission.title).all()
    return [MissionBase.model_validate(mission) for mission in missions]


@router.get("/missions/{mission_id}", response_model=MissionDetail, summary="Детали миссии")
def admin_mission_detail(
    mission_id: int,
    *,
    db: Session = Depends(get_db),
    current_user=Depends(require_hr),
) -> MissionDetail:
    """Детальная карточка миссии."""

    mission = (
        db.query(Mission)
        .options(
            selectinload(Mission.prerequisites),
            selectinload(Mission.competency_rewards).selectinload(MissionCompetencyReward.competency),
            selectinload(Mission.branches),
        )
        .filter(Mission.id == mission_id)
        .first()
    )
    if not mission:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Миссия не найдена")
    return _mission_to_detail(mission)


@router.get("/branches", response_model=list[BranchRead], summary="Ветки миссий")
def admin_branches(*, db: Session = Depends(get_db), current_user=Depends(require_hr)) -> list[BranchRead]:
    """Возвращаем ветки с миссиями."""

    branches = (
        db.query(Branch)
        .options(selectinload(Branch.missions).selectinload(BranchMission.mission))
        .order_by(Branch.title)
        .all()
    )
    return [_branch_to_read(branch) for branch in branches]


@router.post("/branches", response_model=BranchRead, summary="Создать ветку")
def create_branch(
    branch_in: BranchCreate,
    *,
    db: Session = Depends(get_db),
    current_user=Depends(require_hr),
) -> BranchRead:
    """Создаём новую ветку."""

    branch = Branch(
        title=branch_in.title,
        description=branch_in.description,
        category=branch_in.category,
    )
    db.add(branch)
    db.commit()
    db.refresh(branch)
    return _branch_to_read(branch)


@router.put("/branches/{branch_id}", response_model=BranchRead, summary="Обновить ветку")
def update_branch(
    branch_id: int,
    branch_in: BranchUpdate,
    *,
    db: Session = Depends(get_db),
    current_user=Depends(require_hr),
) -> BranchRead:
    """Редактируем ветку."""

    branch = db.query(Branch).filter(Branch.id == branch_id).first()
    if not branch:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Ветка не найдена")

    branch.title = branch_in.title
    branch.description = branch_in.description
    branch.category = branch_in.category

    db.commit()
    db.refresh(branch)
    return _branch_to_read(branch)


@router.get(
    "/competencies",
    response_model=list[CompetencyBase],
    summary="Каталог компетенций",
)
def list_competencies(
    *, db: Session = Depends(get_db), current_user=Depends(require_hr)
) -> list[CompetencyBase]:
    """Справочник компетенций для форм HR."""

    competencies = db.query(Competency).order_by(Competency.name).all()
    return [CompetencyBase.model_validate(competency) for competency in competencies]


@router.get("/artifacts", response_model=list[ArtifactRead], summary="Каталог артефактов")
def list_artifacts(
    *, db: Session = Depends(get_db), current_user=Depends(require_hr)
) -> list[ArtifactRead]:
    """Справочник артефактов."""

    artifacts = db.query(Artifact).order_by(Artifact.name).all()
    return [ArtifactRead.model_validate(artifact) for artifact in artifacts]


@router.get("/stats", response_model=AdminDashboardStats, summary="Сводная аналитика")
def dashboard_stats(
    *, db: Session = Depends(get_db), current_user=Depends(require_hr)
) -> AdminDashboardStats:
    """Основные метрики прогресса и активности пользователей."""

    total_pilots = db.query(User).filter(User.role == UserRole.PILOT).count()
    approved_submissions = db.query(MissionSubmission).filter(
        MissionSubmission.status == SubmissionStatus.APPROVED
    )
    active_pilots = (
        approved_submissions.with_entities(MissionSubmission.user_id).distinct().count()
    )

    completed_counts = approved_submissions.with_entities(
        MissionSubmission.user_id, func.count(MissionSubmission.id)
    ).group_by(MissionSubmission.user_id)

    total_completed = sum(row[1] for row in completed_counts)
    average_completed = total_completed / active_pilots if active_pilots else 0.0

    submission_stats = SubmissionStats(
        pending=db.query(MissionSubmission).filter(MissionSubmission.status == SubmissionStatus.PENDING).count(),
        approved=approved_submissions.count(),
        rejected=db.query(MissionSubmission).filter(MissionSubmission.status == SubmissionStatus.REJECTED).count(),
    )

    branches = (
        db.query(Branch)
        .options(selectinload(Branch.missions))
        .order_by(Branch.title)
        .all()
    )
    branch_stats: list[BranchCompletionStat] = []
    for branch in branches:
        total_missions = len(branch.missions)
        if total_missions == 0 or total_pilots == 0:
            branch_stats.append(
                BranchCompletionStat(branch_id=branch.id, branch_title=branch.title, completion_rate=0.0)
            )
            continue

        approved_count = (
            db.query(func.count(MissionSubmission.id))
            .join(Mission, Mission.id == MissionSubmission.mission_id)
            .join(BranchMission, BranchMission.mission_id == Mission.id)
            .filter(
                BranchMission.branch_id == branch.id,
                MissionSubmission.status == SubmissionStatus.APPROVED,
            )
            .scalar()
        )
        denominator = total_missions * total_pilots
        rate = min(1.0, approved_count / denominator) if denominator else 0.0
        branch_stats.append(
            BranchCompletionStat(branch_id=branch.id, branch_title=branch.title, completion_rate=rate)
        )

    return AdminDashboardStats(
        total_users=total_pilots,
        active_pilots=active_pilots,
        average_completed_missions=round(average_completed, 2),
        submission_stats=submission_stats,
        branch_completion=branch_stats,
    )


@router.post("/artifacts", response_model=ArtifactRead, summary="Создать артефакт")
def create_artifact(
    artifact_in: ArtifactCreate,
    *,
    db: Session = Depends(get_db),
    current_user=Depends(require_hr),
) -> ArtifactRead:
    """Добавляем новый артефакт в каталог."""

    artifact = Artifact(
        name=artifact_in.name,
        description=artifact_in.description,
        rarity=artifact_in.rarity,
        image_url=artifact_in.image_url,
    )
    db.add(artifact)
    db.commit()
    db.refresh(artifact)
    return ArtifactRead.model_validate(artifact)


@router.put("/artifacts/{artifact_id}", response_model=ArtifactRead, summary="Обновить артефакт")
def update_artifact(
    artifact_id: int,
    artifact_in: ArtifactUpdate,
    *,
    db: Session = Depends(get_db),
    current_user=Depends(require_hr),
) -> ArtifactRead:
    """Редактируем существующий артефакт."""

    artifact = db.query(Artifact).filter(Artifact.id == artifact_id).first()
    if not artifact:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Артефакт не найден")

    payload = artifact_in.model_dump(exclude_unset=True)
    for field, value in payload.items():
        setattr(artifact, field, value)

    db.commit()
    db.refresh(artifact)
    return ArtifactRead.model_validate(artifact)


@router.delete(
    "/artifacts/{artifact_id}", status_code=status.HTTP_204_NO_CONTENT, summary="Удалить артефакт"
)
def delete_artifact(
    artifact_id: int,
    *,
    db: Session = Depends(get_db),
    current_user=Depends(require_hr),
) -> None:
    """Удаляем артефакт, если он не привязан к миссиям."""

    artifact = db.query(Artifact).filter(Artifact.id == artifact_id).first()
    if not artifact:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Артефакт не найден")

    missions_with_artifact = db.query(Mission).filter(Mission.artifact_id == artifact_id).count()
    if missions_with_artifact:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Нельзя удалить артефакт, привязанный к миссиям",
        )

    db.delete(artifact)
    db.commit()
    return None


@router.post("/missions", response_model=MissionDetail, summary="Создать миссию")
def create_mission_endpoint(
    mission_in: MissionCreate,
    *,
    db: Session = Depends(get_db),
    current_user=Depends(require_hr),
) -> MissionDetail:
    """Создаём новую миссию."""

    mission = Mission(
        title=mission_in.title,
        description=mission_in.description,
        xp_reward=mission_in.xp_reward,
        mana_reward=mission_in.mana_reward,
        difficulty=mission_in.difficulty,
        minimum_rank_id=mission_in.minimum_rank_id,
        artifact_id=mission_in.artifact_id,
    )
    db.add(mission)
    db.flush()

    for reward in mission_in.competency_rewards:
        mission.competency_rewards.append(
            MissionCompetencyReward(
                mission_id=mission.id,
                competency_id=reward.competency_id,
                level_delta=reward.level_delta,
            )
        )

    for prerequisite_id in mission_in.prerequisite_ids:
        mission.prerequisites.append(
            MissionPrerequisite(mission_id=mission.id, required_mission_id=prerequisite_id)
        )

    if mission_in.branch_id:
        mission.branches.append(
            BranchMission(
                branch_id=mission_in.branch_id,
                mission_id=mission.id,
                order=mission_in.branch_order,
            )
        )

    db.commit()

    mission = _load_mission(db, mission.id)

    return _mission_to_detail(mission)


@router.put("/missions/{mission_id}", response_model=MissionDetail, summary="Обновить миссию")
def update_mission_endpoint(
    mission_id: int,
    mission_in: MissionUpdate,
    *,
    db: Session = Depends(get_db),
    current_user=Depends(require_hr),
) -> MissionDetail:
    """Редактируем миссию."""

    mission = (
        db.query(Mission)
        .options(
            selectinload(Mission.prerequisites),
            selectinload(Mission.competency_rewards),
            selectinload(Mission.branches),
        )
        .filter(Mission.id == mission_id)
        .first()
    )
    if not mission:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Миссия не найдена")

    payload = mission_in.model_dump(exclude_unset=True)

    for attr in ["title", "description", "xp_reward", "mana_reward", "difficulty", "is_active"]:
        if attr in payload:
            setattr(mission, attr, payload[attr])

    if "minimum_rank_id" in payload:
        mission.minimum_rank_id = payload["minimum_rank_id"]

    if "artifact_id" in payload:
        mission.artifact_id = payload["artifact_id"]

    if "competency_rewards" in payload:
        mission.competency_rewards.clear()
        for reward in payload["competency_rewards"]:
            mission.competency_rewards.append(
                MissionCompetencyReward(
                    mission_id=mission.id,
                    competency_id=reward.competency_id,
                    level_delta=reward.level_delta,
                )
            )

    if "prerequisite_ids" in payload:
        mission.prerequisites.clear()
        for prerequisite_id in payload["prerequisite_ids"]:
            mission.prerequisites.append(
                MissionPrerequisite(mission_id=mission.id, required_mission_id=prerequisite_id)
            )

    if "branch_id" in payload:
        mission.branches.clear()
        branch_id = payload["branch_id"]
        if branch_id is not None:
            order = payload.get("branch_order", 1)
            mission.branches.append(
                BranchMission(branch_id=branch_id, mission_id=mission.id, order=order)
            )
    elif "branch_order" in payload and mission.branches:
        mission.branches[0].order = payload["branch_order"]

    db.commit()

    mission = _load_mission(db, mission.id)
    return _mission_to_detail(mission)


@router.get("/ranks", response_model=list[RankBase], summary="Список рангов")
def admin_ranks(*, db: Session = Depends(get_db), current_user=Depends(require_hr)) -> list[RankBase]:
    """Перечень рангов."""

    ranks = db.query(Rank).order_by(Rank.required_xp).all()
    return [RankBase.model_validate(rank) for rank in ranks]


@router.get("/ranks/{rank_id}", response_model=RankDetailed, summary="Детали ранга")
def get_rank(
    rank_id: int,
    *,
    db: Session = Depends(get_db),
    current_user=Depends(require_hr),
) -> RankDetailed:
    """Возвращаем подробную информацию о ранге."""

    try:
        rank = _load_rank(db, rank_id)
    except NoResultFound as exc:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Ранг не найден") from exc
    return _rank_to_detailed(rank)


@router.post("/ranks", response_model=RankDetailed, summary="Создать ранг")
def create_rank(
    rank_in: RankCreate,
    *,
    db: Session = Depends(get_db),
    current_user=Depends(require_hr),
) -> RankDetailed:
    """Создаём новый ранг с требованиями."""

    rank = Rank(title=rank_in.title, description=rank_in.description, required_xp=rank_in.required_xp)
    db.add(rank)
    db.flush()

    for mission_id in rank_in.mission_ids:
        rank.mission_requirements.append(
            RankMissionRequirement(rank_id=rank.id, mission_id=mission_id)
        )

    for item in rank_in.competency_requirements:
        rank.competency_requirements.append(
            RankCompetencyRequirement(
                rank_id=rank.id,
                competency_id=item.competency_id,
                required_level=item.required_level,
            )
        )

    db.commit()

    rank = _load_rank(db, rank.id)
    return _rank_to_detailed(rank)


@router.put("/ranks/{rank_id}", response_model=RankDetailed, summary="Обновить ранг")
def update_rank(
    rank_id: int,
    rank_in: RankUpdate,
    *,
    db: Session = Depends(get_db),
    current_user=Depends(require_hr),
) -> RankDetailed:
    """Редактируем параметры ранга."""

    rank = (
        db.query(Rank)
        .options(
            selectinload(Rank.mission_requirements),
            selectinload(Rank.competency_requirements),
        )
        .filter(Rank.id == rank_id)
        .first()
    )
    if not rank:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Ранг не найден")

    rank.title = rank_in.title
    rank.description = rank_in.description
    rank.required_xp = rank_in.required_xp

    rank.mission_requirements.clear()
    for mission_id in rank_in.mission_ids:
        rank.mission_requirements.append(
            RankMissionRequirement(rank_id=rank.id, mission_id=mission_id)
        )

    rank.competency_requirements.clear()
    for item in rank_in.competency_requirements:
        rank.competency_requirements.append(
            RankCompetencyRequirement(
                rank_id=rank.id,
                competency_id=item.competency_id,
                required_level=item.required_level,
            )
        )

    db.commit()

    rank = _load_rank(db, rank.id)
    return _rank_to_detailed(rank)


@router.get(
    "/submissions",
    response_model=list[MissionSubmissionRead],
    summary="Очередь модерации",
)
def moderation_queue(
    status_filter: SubmissionStatus = SubmissionStatus.PENDING,
    *,
    db: Session = Depends(get_db),
    current_user=Depends(require_hr),
) -> list[MissionSubmissionRead]:
    """Возвращаем отправки со статусом по умолчанию pending."""

    submissions = (
        db.query(MissionSubmission)
        .filter(MissionSubmission.status == status_filter)
        .order_by(MissionSubmission.created_at)
        .all()
    )
    return [MissionSubmissionRead.model_validate(submission) for submission in submissions]


@router.post(
    "/submissions/{submission_id}/approve",
    response_model=MissionSubmissionRead,
    summary="Одобрить миссию",
)
def approve_submission_endpoint(
    submission_id: int,
    *,
    db: Session = Depends(get_db),
    current_user=Depends(require_hr),
) -> MissionSubmissionRead:
    """HR подтверждает выполнение."""

    submission = db.query(MissionSubmission).filter(MissionSubmission.id == submission_id).first()
    if not submission:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Отправка не найдена")
    submission = approve_submission(db, submission)
    return MissionSubmissionRead.model_validate(submission)


@router.post(
    "/submissions/{submission_id}/reject",
    response_model=MissionSubmissionRead,
    summary="Отклонить миссию",
)
def reject_submission_endpoint(
    submission_id: int,
    comment: str | None = None,
    *,
    db: Session = Depends(get_db),
    current_user=Depends(require_hr),
) -> MissionSubmissionRead:
    """HR отклоняет выполнение."""

    submission = db.query(MissionSubmission).filter(MissionSubmission.id == submission_id).first()
    if not submission:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Отправка не найдена")
    submission = reject_submission(db, submission, comment)
    return MissionSubmissionRead.model_validate(submission)