from fastapi import APIRouter, Depends, HTTPException, Query, Response, status
from motor.motor_asyncio import AsyncIOMotorDatabase
from sqlalchemy.orm import Session

from app.database import get_db
from app.dependencies import get_current_user, get_mongo_db_dep
from app.models.user import User
from app.schemas.document import DocumentCreate, DocumentResponse, DocumentUpdate, DocumentVersionResponse, ShareRequest
from app.schemas.collaboration import (
    ActivityResponse,
    CommentCreate,
    CommentResolveRequest,
    CommentResponse,
    NotificationResponse,
)
from app.services.collaboration_service import (
    create_comment,
    delete_comment,
    list_activity,
    list_comments,
    list_notifications,
    mark_notifications_read,
    mention_names,
    resolve_comment,
)
from app.services.document_service import (
    add_member,
    create_document,
    delete_document,
    get_document,
    list_documents,
    record_visit,
    remove_member,
    search_documents,
    update_document,
)
from app.services.user_service import get_user_by_email_or_username
from app.services.history_service import list_versions, restore_version
from html import escape

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


@router.get("/{doc_id}/comments", response_model=list[CommentResponse])
async def get_comments(
    doc_id: str,
    current_user: User = Depends(get_current_user),
    db: AsyncIOMotorDatabase = Depends(get_mongo_db_dep),
) -> list[CommentResponse]:
    comments = await list_comments(db, doc_id, current_user.id)
    if comments is None:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Document not found or access denied")
    return [CommentResponse(**comment) for comment in comments]


@router.post("/{doc_id}/comments", response_model=CommentResponse, status_code=status.HTTP_201_CREATED)
async def post_comment(
    doc_id: str,
    data: CommentCreate,
    current_user: User = Depends(get_current_user),
    db: AsyncIOMotorDatabase = Depends(get_mongo_db_dep),
    sql: Session = Depends(get_db),
) -> CommentResponse:
    mentioned_users = []
    for name in mention_names(data.body):
        mentioned = get_user_by_email_or_username(sql, name.lower())
        if mentioned is not None and mentioned.id != current_user.id:
            mentioned_users.append({"id": mentioned.id})
    comment = await create_comment(
        db,
        doc_id,
        current_user.id,
        current_user.full_name or current_user.username,
        data.body,
        data.parent_id,
        mentioned_users,
    )
    if comment is None:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Document not found or parent comment is invalid")
    return CommentResponse(**comment)


@router.patch("/{doc_id}/comments/{comment_id}/resolve", response_model=CommentResponse)
async def update_comment_resolution(
    doc_id: str,
    comment_id: str,
    data: CommentResolveRequest,
    current_user: User = Depends(get_current_user),
    db: AsyncIOMotorDatabase = Depends(get_mongo_db_dep),
) -> CommentResponse:
    comment = await resolve_comment(
        db, doc_id, comment_id, current_user.id, data.resolved,
        current_user.full_name or current_user.username,
    )
    if comment is None:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Comment not found or access denied")
    return CommentResponse(**comment)


@router.get("/{doc_id}/activity", response_model=list[ActivityResponse])
async def get_activity(
    doc_id: str,
    current_user: User = Depends(get_current_user),
    db: AsyncIOMotorDatabase = Depends(get_mongo_db_dep),
) -> list[ActivityResponse]:
    entries = await list_activity(db, doc_id, current_user.id)
    if entries is None:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Document not found or access denied")
    return [ActivityResponse(**entry) for entry in entries]


@router.get("/notifications", response_model=list[NotificationResponse])
async def get_notifications(
    current_user: User = Depends(get_current_user),
    db: AsyncIOMotorDatabase = Depends(get_mongo_db_dep),
) -> list[NotificationResponse]:
    return [NotificationResponse(**item) for item in await list_notifications(db, current_user.id)]


@router.post("/notifications/read", status_code=status.HTTP_204_NO_CONTENT)
async def read_notifications(
    current_user: User = Depends(get_current_user),
    db: AsyncIOMotorDatabase = Depends(get_mongo_db_dep),
) -> None:
    await mark_notifications_read(db, current_user.id)


@router.get("/{doc_id}/history", response_model=list[DocumentVersionResponse])
async def get_history(
    doc_id: str,
    current_user: User = Depends(get_current_user),
    db: AsyncIOMotorDatabase = Depends(get_mongo_db_dep),
) -> list[DocumentVersionResponse]:
    versions = await list_versions(db, doc_id, current_user.id)
    if versions is None:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Document not found or access denied")
    return [DocumentVersionResponse(**version) for version in versions]


@router.post("/{doc_id}/history/{version_id}/restore", response_model=DocumentResponse)
async def restore_history(
    doc_id: str,
    version_id: str,
    current_user: User = Depends(get_current_user),
    db: AsyncIOMotorDatabase = Depends(get_mongo_db_dep),
) -> DocumentResponse:
    document = await restore_version(
        db,
        doc_id,
        version_id,
        current_user.id,
        current_user.full_name or current_user.username,
    )
    if document is None:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Version not found or restore access denied")
    from app.services.document_service import _serialize

    return DocumentResponse(**_serialize(document))


@router.get("/{doc_id}/export")
async def export_document(
    doc_id: str,
    format: str = Query("html", pattern="^(html|text)$"),
    current_user: User = Depends(get_current_user),
    db: AsyncIOMotorDatabase = Depends(get_mongo_db_dep),
) -> Response:
    document = await get_document(db, doc_id, current_user.id)
    if document is None:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Document not found or access denied")
    body_html = str(document["content"].get("bodyHtml", document["content"].get("body", "")))
    if format == "text":
        import re

        return Response(re.sub(r"<[^>]+>", " ", body_html).strip(), media_type="text/plain")
    html = (
        "<!doctype html><html><head><meta charset='utf-8'>"
        f"<title>{escape(document['title'])}</title></head><body>"
        f"<h1>{escape(document['title'])}</h1>{body_html}</body></html>"
    )
    return Response(html, media_type="text/html")


@router.delete("/{doc_id}/comments/{comment_id}", status_code=status.HTTP_204_NO_CONTENT)
async def remove_comment(
    doc_id: str,
    comment_id: str,
    current_user: User = Depends(get_current_user),
    db: AsyncIOMotorDatabase = Depends(get_mongo_db_dep),
) -> None:
    deleted = await delete_comment(db, comment_id, current_user.id)
    if not deleted:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Comment not found or you are not its author")


@router.get("", response_model=list[DocumentResponse])
async def list_docs(
    type: str | None = Query(None, description="Filter by document type"),
    stead_id: str | None = Query(None, description="Filter by parent stead"),
    parent_page_id: str | None = Query(None, description="Filter by parent page"),
    starred: bool | None = Query(None, description="Filter starred projects"),
    sort: str = Query("updated_at", description="Sort field: updated_at or last_visited_at"),
    current_user: User = Depends(get_current_user),
    db: AsyncIOMotorDatabase = Depends(get_mongo_db_dep),
) -> list[DocumentResponse]:
    sort_field = "last_visited_at" if sort == "last_visited_at" else "updated_at"
    docs = await list_documents(
        db,
        current_user.id,
        doc_type=type,
        stead_id=stead_id,
        parent_page_id=parent_page_id,
        starred=starred,
        sort=sort_field,
    )
    return [DocumentResponse(**doc) for doc in docs]


@router.get("/search", response_model=list[DocumentResponse])
async def search_docs(
    q: str = Query("", min_length=0),
    current_user: User = Depends(get_current_user),
    db: AsyncIOMotorDatabase = Depends(get_mongo_db_dep),
) -> list[DocumentResponse]:
    docs = await search_documents(db, current_user.id, q)
    return [DocumentResponse(**doc) for doc in docs]


@router.get("/{doc_id}", response_model=DocumentResponse)
async def get_doc(
    doc_id: str,
    current_user: User = Depends(get_current_user),
    db: AsyncIOMotorDatabase = Depends(get_mongo_db_dep),
) -> DocumentResponse:
    doc = await get_document(db, doc_id, current_user.id)
    if doc is None:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Document not found or access denied")
    return DocumentResponse(**doc)


@router.post("", response_model=DocumentResponse, status_code=status.HTTP_201_CREATED)
async def create_doc(
    data: DocumentCreate,
    current_user: User = Depends(get_current_user),
    db: AsyncIOMotorDatabase = Depends(get_mongo_db_dep),
) -> DocumentResponse:
    created_by = current_user.full_name or current_user.username
    try:
        doc = await create_document(db, current_user.id, created_by, data)
    except ValueError as exc:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=str(exc)) from exc
    return DocumentResponse(**doc)


@router.patch("/{doc_id}", response_model=DocumentResponse)
async def update_doc(
    doc_id: str,
    data: DocumentUpdate,
    current_user: User = Depends(get_current_user),
    db: AsyncIOMotorDatabase = Depends(get_mongo_db_dep),
) -> DocumentResponse:
    doc = await update_document(db, doc_id, current_user.id, data)
    if doc is None:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Document not found or you do not have edit access",
        )
    return DocumentResponse(**doc)


@router.post("/{doc_id}/visit", response_model=DocumentResponse)
async def visit_doc(
    doc_id: str,
    current_user: User = Depends(get_current_user),
    db: AsyncIOMotorDatabase = Depends(get_mongo_db_dep),
) -> DocumentResponse:
    doc = await record_visit(db, doc_id, current_user.id)
    if doc is None:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Document not found or access denied")
    return DocumentResponse(**doc)


@router.post("/{doc_id}/share", response_model=DocumentResponse)
async def share_doc(
    doc_id: str,
    data: ShareRequest,
    current_user: User = Depends(get_current_user),
    mongo: AsyncIOMotorDatabase = Depends(get_mongo_db_dep),
    sql: Session = Depends(get_db),
) -> DocumentResponse:
    identifier = data.email_or_username.strip().lower()
    user = get_user_by_email_or_username(sql, identifier)
    if user is None:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="User not found")
    if user.id == current_user.id:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="You already own this document")

    doc = await add_member(
        mongo,
        doc_id,
        current_user.id,
        {
            "user_id": user.id,
            "name": user.full_name or user.username,
            "email": user.email,
        },
        data.role,
    )
    if doc is None:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Only the owner can share this document")
    return DocumentResponse(**doc)


@router.delete("/{doc_id}/share/{user_id}", response_model=DocumentResponse)
async def unshare_doc(
    doc_id: str,
    user_id: int,
    current_user: User = Depends(get_current_user),
    mongo: AsyncIOMotorDatabase = Depends(get_mongo_db_dep),
) -> DocumentResponse:
    doc = await remove_member(mongo, doc_id, current_user.id, user_id)
    if doc is None:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Only the owner can update sharing")
    return DocumentResponse(**doc)


@router.delete("/{doc_id}", status_code=status.HTTP_204_NO_CONTENT)
async def delete_doc(
    doc_id: str,
    current_user: User = Depends(get_current_user),
    db: AsyncIOMotorDatabase = Depends(get_mongo_db_dep),
) -> None:
    deleted = await delete_document(db, doc_id, current_user.id)
    if not deleted:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Document not found")