"""프로젝트 관리(아사나식) 모듈 라우터.

- 경로: /project
- 권한:
    · 모듈 진입: 로그인한 회사 직원 전원(도메인 게이트는 OAuth 단에서 처리).
    · 프로젝트 생성/삭제·사용자 배정: ERP 관리자(is_admin) 전용.
    · 서브프로젝트/업무/단계 관리: 해당 프로젝트 멤버(또는 owner) 또는 관리자.
- 데이터: ProjectStore (project_db / PostgreSQL) 전용.
  PROJECT_DB_URL 미설정 시 store 가 None 이며, 각 페이지는 "설정 필요" 안내.
- 메일: 업무가 직원에게 '배정'되거나 '완료'되면 관리자에게 알림(BackgroundTasks).

뷰: 메인은 달력(FullCalendar)/타임라인(vis-timeline) 토글. 추가로 보드(칸반)·리스트.
"""

from __future__ import annotations

import calendar as _calendar
import logging
from datetime import date
from typing import Any

from fastapi import APIRouter, BackgroundTasks, Body, Depends, HTTPException, Request
from fastapi.responses import HTMLResponse, JSONResponse, RedirectResponse

from app.timezone import today_kst

from . import store

logger = logging.getLogger("project.router")

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


# ────────────────────────────────────────────────────────────
# 공용 헬퍼
# ────────────────────────────────────────────────────────────
def _store(request: Request) -> Any:
    return getattr(request.app.state, "project_store", None)


def _require_user(request: Request) -> dict[str, Any]:
    from app.main import get_current_user_record  # noqa: WPS433
    from app.store import has_module  # noqa: WPS433

    user = get_current_user_record(request)
    if user is None:
        raise HTTPException(status_code=401, detail="로그인이 필요합니다.")
    if not has_module(user, "project"):
        raise HTTPException(status_code=403, detail="프로젝트 관리 모듈 권한이 없습니다.")
    return user


def _require_admin(request: Request) -> dict[str, Any]:
    from app.store import is_admin  # noqa: WPS433

    user = _require_user(request)
    if not is_admin(user):
        raise HTTPException(status_code=403, detail="관리자만 할 수 있는 작업입니다.")
    return user


def _can_manage(request: Request, st: Any, user: dict[str, Any], project_id: int) -> bool:
    """프로젝트 단위 관리 권한: 관리자이거나 멤버/owner."""
    from app.store import is_admin  # noqa: WPS433

    if is_admin(user):
        return True
    return bool(st.is_member(project_id=project_id, user_email=user["email"]))


def _require_manage(request: Request, st: Any, user: dict[str, Any], project_id: int) -> None:
    if not _can_manage(request, st, user, project_id):
        raise HTTPException(status_code=403, detail="이 프로젝트에 대한 권한이 없습니다.")


def _admin_emails(request: Request) -> list[str]:
    """알림 수신 관리자 이메일 목록.

    PROJECT_NOTIFY_EMAIL(쉼표구분)이 있으면 우선, 없으면 user_store 의 admin 전원.
    """
    import os

    override = (os.getenv("PROJECT_NOTIFY_EMAIL", "") or "").strip()
    if override:
        return [e.strip() for e in override.split(",") if e.strip()]
    from app.main import user_store  # noqa: WPS433
    from app.store import is_admin  # noqa: WPS433

    return [u["email"] for u in user_store.list_all() if is_admin(u)]


def _notify(
    bg: BackgroundTasks, request: Request, *, subject: str, body: str
) -> None:
    """관리자에게 백그라운드 메일 발송 예약. 수신자 없거나 SMTP 미설정 시 조용히 skip."""
    from app.mail import send_email  # noqa: WPS433

    recipients = _admin_emails(request)
    if not recipients:
        return
    bg.add_task(send_email, to=recipients, subject=subject, body=body)


def _render_config_needed(request: Request, user: dict[str, Any]) -> HTMLResponse:
    from app.main import build_erp_nav, render_template  # noqa: WPS433
    from app.store import is_admin  # noqa: WPS433

    return render_template(
        request,
        "denied.html",
        {
            "reason": "프로젝트 관리 모듈이 아직 설정되지 않았습니다. "
            "PROJECT_DB_URL 환경변수를 설정하고 "
            "scripts/sql/project_db_init.sql 로 project_db 를 초기화한 뒤 "
            "컨테이너를 재기동하세요.",
            "user": user,
            "is_admin": is_admin(user),
            "nav_items": build_erp_nav(user, active="project"),
        },
        status_code=503,
    )


def _build_tree(projects: list[dict[str, Any]]) -> list[dict[str, Any]]:
    """평면 프로젝트 목록 → parent_id 기준 트리(children 키)."""
    by_id: dict[int, dict[str, Any]] = {}
    roots: list[dict[str, Any]] = []
    for p in projects:
        p = {**p, "children": []}
        by_id[p["id"]] = p
    for p in by_id.values():
        parent_id = p.get("parent_id")
        if parent_id and parent_id in by_id:
            by_id[parent_id]["children"].append(p)
        else:
            roots.append(p)
    return roots


# ────────────────────────────────────────────────────────────
# 월간 달력 레이아웃 (휴가 모듈과 동일한 구글식 bar 레인 배치)
# ────────────────────────────────────────────────────────────
def _assign_lanes(bars: list[dict[str, Any]]) -> int:
    """주(week) 내 bar 들에 겹치지 않는 lane(행)을 그리디 배정. 사용 lane 수 반환."""
    bars.sort(key=lambda b: (b["start_col"], -b["span"]))
    lane_end: list[int] = []  # lane 별 마지막 점유 col(포함)
    for b in bars:
        placed = False
        for li, end_col in enumerate(lane_end):
            if b["start_col"] > end_col:
                b["lane"] = li
                lane_end[li] = b["start_col"] + b["span"] - 1
                placed = True
                break
        if not placed:
            b["lane"] = len(lane_end)
            lane_end.append(b["start_col"] + b["span"] - 1)
    return len(lane_end)


def _task_span(task: dict[str, Any]) -> tuple[date, date] | None:
    """업무의 달력 표시 기간(start..due). 둘 중 하나만 있으면 단일일. 없으면 None."""
    s = task.get("start_date")
    d = task.get("due_date")
    try:
        sd = date.fromisoformat(s[:10]) if s else None
        dd = date.fromisoformat(d[:10]) if d else None
    except (ValueError, TypeError):
        return None
    if sd and dd:
        return (sd, dd) if sd <= dd else (dd, sd)
    if sd:
        return (sd, sd)
    if dd:
        return (dd, dd)
    return None


def _build_task_calendar(
    tasks: list[dict[str, Any]], year: int, month: int
) -> list[dict[str, Any]]:
    """업무 리스트 → 월간 달력 주(week) 데이터(휴가 _build_calendar 와 동일 구조)."""
    cal = _calendar.Calendar(firstweekday=6)  # 일요일 시작
    weeks_dates = cal.monthdatescalendar(year, month)
    today = today_kst()

    spans: list[tuple[date, date, dict[str, Any]]] = []
    for t in tasks:
        sp = _task_span(t)
        if sp:
            spans.append((sp[0], sp[1], t))

    weeks: list[dict[str, Any]] = []
    for week in weeks_dates:
        w_start, w_end = week[0], week[-1]
        days = [
            {
                "date": d.isoformat(),
                "day": d.day,
                "in_month": d.month == month,
                "is_today": d == today,
                "is_sunday": d.weekday() == 6,
                "is_saturday": d.weekday() == 5,
            }
            for d in week
        ]
        bars: list[dict[str, Any]] = []
        for rs, re_, t in spans:
            if re_ < w_start or rs > w_end:
                continue
            seg_start = max(rs, w_start)
            seg_end = min(re_, w_end)
            bars.append(
                {
                    "id": t["id"],
                    "label": t["title"],
                    "color": t.get("project_color") or "#4573d2",
                    "completed": bool(t.get("completed_at")),
                    "start_col": (seg_start - w_start).days,
                    "span": (seg_end - seg_start).days + 1,
                    "continues_left": rs < w_start,
                    "continues_right": re_ > w_end,
                }
            )
        lane_count = _assign_lanes(bars)
        weeks.append({"days": days, "bars": bars, "lane_count": lane_count})
    return weeks


# ────────────────────────────────────────────────────────────
# 페이지
# ────────────────────────────────────────────────────────────
@router.get("/health")
async def health(request: Request) -> JSONResponse:
    st = _store(request)
    if st is None:
        return JSONResponse({"status": "not_configured"}, status_code=503)
    try:
        st.list_projects(include_archived=False)
        return JSONResponse({"status": "ok"})
    except Exception as exc:  # noqa: BLE001
        return JSONResponse({"status": "error", "detail": str(exc)}, status_code=500)


@router.get("/", response_class=HTMLResponse)
async def index(request: Request) -> HTMLResponse:
    from app.main import build_erp_nav, render_template  # noqa: WPS433
    from app.store import is_admin  # noqa: WPS433

    user = _require_user(request)
    st = _store(request)
    if st is None:
        return _render_config_needed(request, user)

    admin = is_admin(user)
    projects = st.list_projects(
        include_archived=False,
        member_email=None if admin else user["email"],
    )
    tree = _build_tree(projects)
    my_tasks = st.list_tasks(assignee_email=user["email"], limit=500)
    return render_template(
        request,
        "project/index.html",
        {
            "user": user,
            "is_admin": admin,
            "nav_items": build_erp_nav(user, active="project"),
            "page_title": "프로젝트 관리",
            "page_subtitle": "달력·타임라인·보드로 프로젝트를 관리하세요.",
            "tree": tree,
            "my_tasks": my_tasks,
            "today": today_kst().isoformat(),
        },
    )


@router.get("/p/{project_id}", response_class=HTMLResponse)
async def project_page(request: Request, project_id: int) -> HTMLResponse:
    from app.main import build_erp_nav, render_template  # noqa: WPS433
    from app.store import is_admin  # noqa: WPS433

    user = _require_user(request)
    st = _store(request)
    if st is None:
        return _render_config_needed(request, user)

    project = st.get_project(project_id=project_id)
    if project is None:
        raise HTTPException(status_code=404, detail="프로젝트를 찾을 수 없습니다.")

    admin = is_admin(user)
    all_projects = st.list_projects(
        include_archived=False,
        member_email=None if admin else user["email"],
    )
    tree = _build_tree(all_projects)
    stages = st.list_stages(project_id=project_id)
    tasks = st.list_tasks(project_id=project_id, include_subprojects=True, limit=2000)
    members = st.list_members(project_id=project_id)
    can_manage = _can_manage(request, st, user, project_id)
    subprojects = [p for p in all_projects if p.get("parent_id") == project_id]

    # 달력(휴가식 월간 그리드) — ?y=&m= 로 월 이동, 기본 이번 달
    today = today_kst()
    try:
        year = int(request.query_params.get("y") or today.year)
        month = int(request.query_params.get("m") or today.month)
        if not (1 <= month <= 12):
            year, month = today.year, today.month
    except (TypeError, ValueError):
        year, month = today.year, today.month
    weeks = _build_task_calendar(tasks, year, month)
    prev_y, prev_m = (year - 1, 12) if month == 1 else (year, month - 1)
    next_y, next_m = (year + 1, 1) if month == 12 else (year, month + 1)

    return render_template(
        request,
        "project/project.html",
        {
            "user": user,
            "is_admin": admin,
            "can_manage": can_manage,
            "nav_items": build_erp_nav(user, active="project"),
            "page_title": project["name"],
            "page_subtitle": project.get("description") or "프로젝트 보드",
            "project": project,
            "tree": tree,
            "stages": stages,
            "tasks": tasks,
            "members": members,
            "subprojects": subprojects,
            "priority_labels": store.PRIORITY_LABELS,
            "color_palette": list(store.COLOR_PALETTE),
            "today": today.isoformat(),
            "year": year,
            "month": month,
            "prev_y": prev_y, "prev_m": prev_m,
            "next_y": next_y, "next_m": next_m,
            "weekdays": ["일", "월", "화", "수", "목", "금", "토"],
            "weeks": weeks,
        },
    )


# ────────────────────────────────────────────────────────────
# JSON API — 프로젝트
# ────────────────────────────────────────────────────────────
def _db_or_503(request: Request) -> Any:
    st = _store(request)
    if st is None:
        raise HTTPException(status_code=503, detail="프로젝트 모듈이 설정되지 않았습니다.")
    return st


@router.get("/api/projects")
async def api_list_projects(request: Request) -> JSONResponse:
    from app.store import is_admin  # noqa: WPS433

    user = _require_user(request)
    st = _db_or_503(request)
    admin = is_admin(user)
    projects = st.list_projects(
        include_archived=False,
        member_email=None if admin else user["email"],
    )
    return JSONResponse({"projects": projects, "tree": _build_tree(projects)})


@router.post("/api/projects")
async def api_create_project(
    request: Request, payload: dict[str, Any] = Body(...)
) -> JSONResponse:
    """최상위 프로젝트 생성 — 관리자 전용."""
    user = _require_admin(request)
    st = _db_or_503(request)
    try:
        project = st.create_project(
            name=payload.get("name", ""),
            parent_id=None,
            description=payload.get("description", ""),
            color=payload.get("color", ""),
            owner_email=payload.get("owner_email", "") or user["email"],
            start_date=payload.get("start_date"),
            due_date=payload.get("due_date"),
            created_by=user["email"],
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc))
    return JSONResponse({"project": project}, status_code=201)


@router.post("/api/projects/{project_id}/subprojects")
async def api_create_subproject(
    request: Request, project_id: int, payload: dict[str, Any] = Body(...)
) -> JSONResponse:
    """서브프로젝트 생성 — 멤버(또는 관리자)."""
    user = _require_user(request)
    st = _db_or_503(request)
    _require_manage(request, st, user, project_id)
    try:
        project = st.create_project(
            name=payload.get("name", ""),
            parent_id=project_id,
            description=payload.get("description", ""),
            color=payload.get("color", ""),
            owner_email=payload.get("owner_email", "") or user["email"],
            start_date=payload.get("start_date"),
            due_date=payload.get("due_date"),
            created_by=user["email"],
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc))
    except KeyError as exc:
        raise HTTPException(status_code=404, detail=str(exc))
    return JSONResponse({"project": project}, status_code=201)


@router.put("/api/projects/{project_id}")
async def api_update_project(
    request: Request, project_id: int, payload: dict[str, Any] = Body(...)
) -> JSONResponse:
    user = _require_user(request)
    st = _db_or_503(request)
    _require_manage(request, st, user, project_id)
    try:
        project = st.update_project(project_id=project_id, fields=payload)
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc))
    except KeyError:
        raise HTTPException(status_code=404, detail="프로젝트를 찾을 수 없습니다.")
    return JSONResponse({"project": project})


@router.delete("/api/projects/{project_id}")
async def api_delete_project(request: Request, project_id: int) -> JSONResponse:
    """프로젝트 삭제 — 서브프로젝트는 멤버도, 최상위는 관리자만.

    아사나 요구사항: 배정된 사용자는 '서브프로젝트' 추가/삭제 가능.
    최상위 프로젝트 삭제는 관리자 전용.
    """
    from app.store import is_admin  # noqa: WPS433

    user = _require_user(request)
    st = _db_or_503(request)
    project = st.get_project(project_id=project_id)
    if project is None:
        raise HTTPException(status_code=404, detail="프로젝트를 찾을 수 없습니다.")
    is_sub = project.get("parent_id") is not None
    if is_sub:
        _require_manage(request, st, user, project_id)
    elif not is_admin(user):
        raise HTTPException(status_code=403, detail="최상위 프로젝트 삭제는 관리자만 가능합니다.")
    st.delete_project(project_id=project_id)
    return JSONResponse({"ok": True})


# ────────────────────────────────────────────────────────────
# JSON API — 멤버 (관리자가 사용자 배정)
# ────────────────────────────────────────────────────────────
@router.get("/api/assignable-users")
async def api_assignable_users(request: Request) -> JSONResponse:
    """배정 후보 = 등록된 사용자 중 프로젝트 권한(project 모듈) 보유자. 관리자 전용.

    관리자 페이지의 '프로젝트 관리' 토글을 켠 직원이 자동으로 후보가 된다.
    """
    _require_admin(request)
    from app.main import user_store  # noqa: WPS433
    from app.store import has_module  # noqa: WPS433

    out = [
        {
            "email": u["email"],
            "name": u.get("name") or u["email"].split("@")[0],
            "id": u["email"].split("@")[0],
        }
        for u in user_store.list_all()
        if has_module(u, "project")
    ]
    out.sort(key=lambda x: x["id"])
    return JSONResponse({"users": out})


@router.get("/api/projects/{project_id}/members")
async def api_list_members(request: Request, project_id: int) -> JSONResponse:
    _require_user(request)
    st = _db_or_503(request)
    return JSONResponse({"members": st.list_members(project_id=project_id)})


@router.post("/api/projects/{project_id}/members")
async def api_add_member(
    request: Request, project_id: int, payload: dict[str, Any] = Body(...)
) -> JSONResponse:
    """사용자를 프로젝트에 배정 — 관리자 전용."""
    _require_admin(request)
    st = _db_or_503(request)
    try:
        member = st.add_member(
            project_id=project_id,
            user_email=payload.get("user_email", ""),
            user_name=payload.get("user_name", ""),
            role=payload.get("role", "member"),
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc))
    return JSONResponse({"member": member}, status_code=201)


@router.delete("/api/projects/{project_id}/members/{user_email}")
async def api_remove_member(
    request: Request, project_id: int, user_email: str
) -> JSONResponse:
    _require_admin(request)
    st = _db_or_503(request)
    st.remove_member(project_id=project_id, user_email=user_email)
    return JSONResponse({"ok": True})


# ────────────────────────────────────────────────────────────
# JSON API — 단계 (stages)
# ────────────────────────────────────────────────────────────
@router.get("/api/projects/{project_id}/stages")
async def api_list_stages(request: Request, project_id: int) -> JSONResponse:
    _require_user(request)
    st = _db_or_503(request)
    return JSONResponse({"stages": st.list_stages(project_id=project_id)})


@router.post("/api/projects/{project_id}/stages")
async def api_add_stage(
    request: Request, project_id: int, payload: dict[str, Any] = Body(...)
) -> JSONResponse:
    user = _require_user(request)
    st = _db_or_503(request)
    _require_manage(request, st, user, project_id)
    try:
        stage = st.add_stage(
            project_id=project_id,
            name=payload.get("name", ""),
            is_done_stage=bool(payload.get("is_done_stage", False)),
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc))
    return JSONResponse({"stage": stage}, status_code=201)


@router.delete("/api/projects/{project_id}/stages/{stage_id}")
async def api_delete_stage(
    request: Request, project_id: int, stage_id: int
) -> JSONResponse:
    user = _require_user(request)
    st = _db_or_503(request)
    _require_manage(request, st, user, project_id)
    try:
        st.delete_stage(stage_id=stage_id)
    except KeyError:
        raise HTTPException(status_code=404, detail="단계를 찾을 수 없습니다.")
    return JSONResponse({"ok": True})


# ────────────────────────────────────────────────────────────
# JSON API — 업무 (tasks)
# ────────────────────────────────────────────────────────────
@router.get("/api/projects/{project_id}/tasks")
async def api_list_tasks(request: Request, project_id: int) -> JSONResponse:
    _require_user(request)
    st = _db_or_503(request)
    tasks = st.list_tasks(project_id=project_id, include_subprojects=True, limit=2000)
    return JSONResponse({"tasks": tasks})


@router.get("/api/my-tasks")
async def api_my_tasks(request: Request) -> JSONResponse:
    user = _require_user(request)
    st = _db_or_503(request)
    return JSONResponse({"tasks": st.list_tasks(assignee_email=user["email"], limit=1000)})


@router.post("/api/projects/{project_id}/tasks")
async def api_create_task(
    request: Request,
    project_id: int,
    bg: BackgroundTasks,
    payload: dict[str, Any] = Body(...),
) -> JSONResponse:
    user = _require_user(request)
    st = _db_or_503(request)
    _require_manage(request, st, user, project_id)
    project = st.get_project(project_id=project_id)
    if project is None:
        raise HTTPException(status_code=404, detail="프로젝트를 찾을 수 없습니다.")
    try:
        task = st.create_task(
            project_id=project_id,
            title=payload.get("title", ""),
            stage_id=payload.get("stage_id"),
            description=payload.get("description", ""),
            assignee_email=payload.get("assignee_email", ""),
            assignee_name=payload.get("assignee_name", ""),
            priority=payload.get("priority", "normal"),
            start_date=payload.get("start_date"),
            due_date=payload.get("due_date"),
            created_by=user["email"],
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc))
    # 생성과 동시에 담당자 지정 시 관리자 알림
    if task.get("assignee_email"):
        _notify(
            bg, request,
            subject=store.build_subject_assigned(
                project_name=project["name"],
                task_title=task["title"],
                assignee=task["assignee_email"],
            ),
            body=(
                f"프로젝트: {project['name']}\n"
                f"업무: {task['title']}\n"
                f"담당자: {task.get('assignee_name') or task['assignee_email']} "
                f"({task['assignee_email']})\n"
                f"마감일: {task.get('due_date') or '-'}\n"
                f"등록자: {user['email']}\n"
            ),
        )
    return JSONResponse({"task": task}, status_code=201)


@router.put("/api/tasks/{task_id}")
async def api_update_task(
    request: Request,
    task_id: int,
    bg: BackgroundTasks,
    payload: dict[str, Any] = Body(...),
) -> JSONResponse:
    user = _require_user(request)
    st = _db_or_503(request)
    existing = st.get_task(task_id=task_id)
    if existing is None:
        raise HTTPException(status_code=404, detail="업무를 찾을 수 없습니다.")
    _require_manage(request, st, user, existing["project_id"])
    try:
        task = st.update_task(task_id=task_id, fields=payload, actor=user["email"])
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc))
    except KeyError:
        raise HTTPException(status_code=404, detail="업무를 찾을 수 없습니다.")

    project_name = task.get("project_name") or ""
    if task.get("_newly_assigned"):
        _notify(
            bg, request,
            subject=store.build_subject_assigned(
                project_name=project_name,
                task_title=task["title"],
                assignee=task["_newly_assigned"],
            ),
            body=(
                f"프로젝트: {project_name}\n"
                f"업무: {task['title']}\n"
                f"담당자: {task.get('assignee_name') or task['_newly_assigned']} "
                f"({task['_newly_assigned']})\n"
                f"마감일: {task.get('due_date') or '-'}\n"
                f"변경자: {user['email']}\n"
            ),
        )
    if task.get("_newly_completed"):
        _notify(
            bg, request,
            subject=store.build_subject_completed(
                project_name=project_name, task_title=task["title"]
            ),
            body=(
                f"프로젝트: {project_name}\n"
                f"완료된 업무: {task['title']}\n"
                f"담당자: {task.get('assignee_name') or task.get('assignee_email') or '-'}\n"
                f"완료 처리: {user['email']}\n"
            ),
        )
    return JSONResponse({"task": task})


@router.delete("/api/tasks/{task_id}")
async def api_delete_task(request: Request, task_id: int) -> JSONResponse:
    user = _require_user(request)
    st = _db_or_503(request)
    existing = st.get_task(task_id=task_id)
    if existing is None:
        raise HTTPException(status_code=404, detail="업무를 찾을 수 없습니다.")
    _require_manage(request, st, user, existing["project_id"])
    st.delete_task(task_id=task_id)
    return JSONResponse({"ok": True})


@router.get("/api/projects/{project_id}/activity")
async def api_activity(request: Request, project_id: int) -> JSONResponse:
    _require_user(request)
    st = _db_or_503(request)
    return JSONResponse({"activity": st.list_activity(project_id=project_id, limit=100)})