"""Project CRUD endpoints including sub-projects, function groups, and functions."""

from fastapi import APIRouter, Depends, HTTPException, status, Query
from sqlalchemy import select, func
from sqlalchemy.ext.asyncio import AsyncSession

from app.api.deps import require_permission
from app.db.session import get_async_session
from app.models import User, Project, SubProject, ProjectFunctionGroup, ProjectFunction
from app.schemas.project import (
    ProjectCreateRequest,
    ProjectUpdateRequest,
    ProjectResponse,
    ProjectListResponse,
    SubProjectCreateRequest,
    SubProjectUpdateRequest,
    SubProjectResponse,
    SubProjectListResponse,
    ProjectFunctionGroupCreateRequest,
    ProjectFunctionGroupUpdateRequest,
    ProjectFunctionGroupResponse,
    ProjectFunctionGroupListResponse,
    ProjectFunctionCreateRequest,
    ProjectFunctionUpdateRequest,
    ProjectFunctionResponse,
    ProjectFunctionListResponse,
)

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


# ===== Project Endpoints =====


@router.get("", response_model=ProjectListResponse)
async def list_projects(
    page: int = Query(1, ge=1),
    size: int = Query(20, ge=1, le=100),
    search: str | None = Query(None, description="Search in project name"),
    status: str | None = Query(
        None,
        description="Filter by status (draft, confirmed, in_progress, completed, cancelled)",
    ),
    current_user: User = Depends(require_permission("projects:read")),
    session: AsyncSession = Depends(get_async_session),
):
    """List projects with search, filters, pagination."""
    account_id = current_user.account_id

    base_q = select(Project).where(Project.account_id == account_id)

    if search:
        pattern = f"%{search}%"
        base_q = base_q.where(Project.name.ilike(pattern))

    if status:
        base_q = base_q.where(Project.status == status)

    count_q = select(func.count()).select_from(base_q.subquery())
    total = (await session.execute(count_q)).scalar() or 0

    q = base_q.order_by(Project.updated_at.desc()).offset((page - 1) * size).limit(size)
    result = await session.execute(q)
    items = result.scalars().all()

    return ProjectListResponse(
        items=[ProjectResponse.model_validate(i) for i in items],
        total=total,
        page=page,
        size=size,
    )


@router.post("", response_model=ProjectResponse, status_code=status.HTTP_201_CREATED)
async def create_project(
    body: ProjectCreateRequest,
    current_user: User = Depends(require_permission("projects:write")),
    session: AsyncSession = Depends(get_async_session),
):
    """Create a new project."""
    account_id = current_user.account_id
    project = Project(account_id=account_id, **body.model_dump())
    session.add(project)
    await session.commit()
    await session.refresh(project)
    return ProjectResponse.model_validate(project)


@router.get("/{project_id}", response_model=ProjectResponse)
async def get_project(
    project_id: str,
    current_user: User = Depends(require_permission("projects:read")),
    session: AsyncSession = Depends(get_async_session),
):
    """Get a specific project."""
    account_id = current_user.account_id
    result = await session.execute(
        select(Project).where(
            Project.id == project_id, Project.account_id == account_id
        )
    )
    project = result.scalars().first()
    if not project:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Project not found"
        )
    return ProjectResponse.model_validate(project)


@router.put("/{project_id}", response_model=ProjectResponse)
async def update_project(
    project_id: str,
    body: ProjectUpdateRequest,
    current_user: User = Depends(require_permission("projects:write")),
    session: AsyncSession = Depends(get_async_session),
):
    """Update an existing project."""
    account_id = current_user.account_id
    result = await session.execute(
        select(Project).where(
            Project.id == project_id, Project.account_id == account_id
        )
    )
    project = result.scalars().first()
    if not project:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Project not found"
        )

    update_data = body.model_dump(exclude_unset=True)
    for field, value in update_data.items():
        setattr(project, field, value)

    await session.commit()
    await session.refresh(project)
    return ProjectResponse.model_validate(project)


@router.delete("/{project_id}", status_code=status.HTTP_204_NO_CONTENT)
async def delete_project(
    project_id: str,
    current_user: User = Depends(require_permission("projects:delete")),
    session: AsyncSession = Depends(get_async_session),
):
    """Delete a project."""
    account_id = current_user.account_id
    result = await session.execute(
        select(Project).where(
            Project.id == project_id, Project.account_id == account_id
        )
    )
    project = result.scalars().first()
    if not project:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Project not found"
        )

    await session.delete(project)
    await session.commit()
    return None


# ===== SubProject Endpoints =====


@router.get("/{project_id}/subprojects", response_model=SubProjectListResponse)
async def list_subprojects(
    project_id: str,
    page: int = Query(1, ge=1),
    size: int = Query(50, ge=1, le=200),
    current_user: User = Depends(require_permission("projects:read")),
    session: AsyncSession = Depends(get_async_session),
):
    """List subprojects for a project."""
    account_id = current_user.account_id

    # Verify project ownership
    proj_result = await session.execute(
        select(Project.id).where(
            Project.id == project_id, Project.account_id == account_id
        )
    )
    if not proj_result.scalars().first():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Project not found"
        )

    base_q = select(SubProject).where(SubProject.project_id == project_id)
    count_q = select(func.count()).select_from(base_q.subquery())
    total = (await session.execute(count_q)).scalar() or 0

    q = base_q.order_by(SubProject.sort_order).offset((page - 1) * size).limit(size)
    result = await session.execute(q)
    items = result.scalars().all()

    return SubProjectListResponse(
        items=[SubProjectResponse.model_validate(i) for i in items],
        total=total,
        page=page,
        size=size,
    )


@router.post(
    "/{project_id}/subprojects",
    response_model=SubProjectResponse,
    status_code=status.HTTP_201_CREATED,
)
async def create_subproject(
    project_id: str,
    body: SubProjectCreateRequest,
    current_user: User = Depends(require_permission("projects:write")),
    session: AsyncSession = Depends(get_async_session),
):
    """Create a subproject within a project."""
    account_id = current_user.account_id

    # Verify project ownership
    proj_result = await session.execute(
        select(Project.id).where(
            Project.id == project_id, Project.account_id == account_id
        )
    )
    if not proj_result.scalars().first():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Project not found"
        )

    # Verify parent subproject if provided
    if body.parent_id:
        parent_result = await session.execute(
            select(SubProject.id).where(
                SubProject.id == body.parent_id,
                SubProject.project_id == project_id,
            )
        )
        if not parent_result.scalars().first():
            raise HTTPException(
                status_code=status.HTTP_404_NOT_FOUND,
                detail="Parent subproject not found",
            )

    sub = SubProject(project_id=project_id, **body.model_dump())
    session.add(sub)
    await session.commit()
    await session.refresh(sub)
    return SubProjectResponse.model_validate(sub)


@router.get("/{project_id}/subprojects/{sub_id}", response_model=SubProjectResponse)
async def get_subproject(
    project_id: str,
    sub_id: str,
    current_user: User = Depends(require_permission("projects:read")),
    session: AsyncSession = Depends(get_async_session),
):
    """Get a specific subproject."""
    account_id = current_user.account_id

    # Verify project ownership
    proj_result = await session.execute(
        select(Project.id).where(
            Project.id == project_id, Project.account_id == account_id
        )
    )
    if not proj_result.scalars().first():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Project not found"
        )

    result = await session.execute(
        select(SubProject).where(
            SubProject.id == sub_id, SubProject.project_id == project_id
        )
    )
    sub = result.scalars().first()
    if not sub:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="SubProject not found"
        )
    return SubProjectResponse.model_validate(sub)


@router.put("/{project_id}/subprojects/{sub_id}", response_model=SubProjectResponse)
async def update_subproject(
    project_id: str,
    sub_id: str,
    body: SubProjectUpdateRequest,
    current_user: User = Depends(require_permission("projects:write")),
    session: AsyncSession = Depends(get_async_session),
):
    """Update a subproject."""
    account_id = current_user.account_id

    # Verify project ownership
    proj_result = await session.execute(
        select(Project.id).where(
            Project.id == project_id, Project.account_id == account_id
        )
    )
    if not proj_result.scalars().first():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Project not found"
        )

    result = await session.execute(
        select(SubProject).where(
            SubProject.id == sub_id, SubProject.project_id == project_id
        )
    )
    sub = result.scalars().first()
    if not sub:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="SubProject not found"
        )

    update_data = body.model_dump(exclude_unset=True)
    for field, value in update_data.items():
        setattr(sub, field, value)

    await session.commit()
    await session.refresh(sub)
    return SubProjectResponse.model_validate(sub)


@router.delete(
    "/{project_id}/subprojects/{sub_id}", status_code=status.HTTP_204_NO_CONTENT
)
async def delete_subproject(
    project_id: str,
    sub_id: str,
    current_user: User = Depends(require_permission("projects:delete")),
    session: AsyncSession = Depends(get_async_session),
):
    """Delete a subproject."""
    account_id = current_user.account_id

    # Verify project ownership
    proj_result = await session.execute(
        select(Project.id).where(
            Project.id == project_id, Project.account_id == account_id
        )
    )
    if not proj_result.scalars().first():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Project not found"
        )

    result = await session.execute(
        select(SubProject).where(
            SubProject.id == sub_id, SubProject.project_id == project_id
        )
    )
    sub = result.scalars().first()
    if not sub:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="SubProject not found"
        )

    await session.delete(sub)
    await session.commit()
    return None


# ===== ProjectFunctionGroup Endpoints =====


@router.get(
    "/{project_id}/function-groups", response_model=ProjectFunctionGroupListResponse
)
async def list_function_groups(
    project_id: str,
    page: int = Query(1, ge=1),
    size: int = Query(50, ge=1, le=200),
    current_user: User = Depends(require_permission("projects:read")),
    session: AsyncSession = Depends(get_async_session),
):
    """List function groups for a project."""
    account_id = current_user.account_id

    proj_result = await session.execute(
        select(Project.id).where(
            Project.id == project_id, Project.account_id == account_id
        )
    )
    if not proj_result.scalars().first():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Project not found"
        )

    base_q = select(ProjectFunctionGroup).where(
        ProjectFunctionGroup.project_id == project_id
    )
    count_q = select(func.count()).select_from(base_q.subquery())
    total = (await session.execute(count_q)).scalar() or 0

    q = (
        base_q.order_by(ProjectFunctionGroup.sort_order)
        .offset((page - 1) * size)
        .limit(size)
    )
    result = await session.execute(q)
    items = result.scalars().all()

    return ProjectFunctionGroupListResponse(
        items=[ProjectFunctionGroupResponse.model_validate(i) for i in items],
        total=total,
        page=page,
        size=size,
    )


@router.post(
    "/{project_id}/function-groups",
    response_model=ProjectFunctionGroupResponse,
    status_code=status.HTTP_201_CREATED,
)
async def create_function_group(
    project_id: str,
    body: ProjectFunctionGroupCreateRequest,
    current_user: User = Depends(require_permission("projects:write")),
    session: AsyncSession = Depends(get_async_session),
):
    """Create a function group within a project."""
    account_id = current_user.account_id

    proj_result = await session.execute(
        select(Project.id).where(
            Project.id == project_id, Project.account_id == account_id
        )
    )
    if not proj_result.scalars().first():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Project not found"
        )

    fg = ProjectFunctionGroup(project_id=project_id, **body.model_dump())
    session.add(fg)
    await session.commit()
    await session.refresh(fg)
    return ProjectFunctionGroupResponse.model_validate(fg)


@router.get(
    "/{project_id}/function-groups/{fg_id}", response_model=ProjectFunctionGroupResponse
)
async def get_function_group(
    project_id: str,
    fg_id: str,
    current_user: User = Depends(require_permission("projects:read")),
    session: AsyncSession = Depends(get_async_session),
):
    """Get a specific function group."""
    account_id = current_user.account_id

    proj_result = await session.execute(
        select(Project.id).where(
            Project.id == project_id, Project.account_id == account_id
        )
    )
    if not proj_result.scalars().first():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Project not found"
        )

    result = await session.execute(
        select(ProjectFunctionGroup).where(
            ProjectFunctionGroup.id == fg_id,
            ProjectFunctionGroup.project_id == project_id,
        )
    )
    fg = result.scalars().first()
    if not fg:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Function group not found"
        )
    return ProjectFunctionGroupResponse.model_validate(fg)


@router.put(
    "/{project_id}/function-groups/{fg_id}", response_model=ProjectFunctionGroupResponse
)
async def update_function_group(
    project_id: str,
    fg_id: str,
    body: ProjectFunctionGroupUpdateRequest,
    current_user: User = Depends(require_permission("projects:write")),
    session: AsyncSession = Depends(get_async_session),
):
    """Update a function group."""
    account_id = current_user.account_id

    proj_result = await session.execute(
        select(Project.id).where(
            Project.id == project_id, Project.account_id == account_id
        )
    )
    if not proj_result.scalars().first():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Project not found"
        )

    result = await session.execute(
        select(ProjectFunctionGroup).where(
            ProjectFunctionGroup.id == fg_id,
            ProjectFunctionGroup.project_id == project_id,
        )
    )
    fg = result.scalars().first()
    if not fg:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Function group not found"
        )

    update_data = body.model_dump(exclude_unset=True)
    for field, value in update_data.items():
        setattr(fg, field, value)

    await session.commit()
    await session.refresh(fg)
    return ProjectFunctionGroupResponse.model_validate(fg)


@router.delete(
    "/{project_id}/function-groups/{fg_id}", status_code=status.HTTP_204_NO_CONTENT
)
async def delete_function_group(
    project_id: str,
    fg_id: str,
    current_user: User = Depends(require_permission("projects:delete")),
    session: AsyncSession = Depends(get_async_session),
):
    """Delete a function group."""
    account_id = current_user.account_id

    proj_result = await session.execute(
        select(Project.id).where(
            Project.id == project_id, Project.account_id == account_id
        )
    )
    if not proj_result.scalars().first():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Project not found"
        )

    result = await session.execute(
        select(ProjectFunctionGroup).where(
            ProjectFunctionGroup.id == fg_id,
            ProjectFunctionGroup.project_id == project_id,
        )
    )
    fg = result.scalars().first()
    if not fg:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Function group not found"
        )

    await session.delete(fg)
    await session.commit()
    return None


# ===== ProjectFunction Endpoints =====


@router.get(
    "/{project_id}/function-groups/{fg_id}/functions",
    response_model=ProjectFunctionListResponse,
)
async def list_project_functions(
    project_id: str,
    fg_id: str,
    page: int = Query(1, ge=1),
    size: int = Query(50, ge=1, le=200),
    current_user: User = Depends(require_permission("projects:read")),
    session: AsyncSession = Depends(get_async_session),
):
    """List functions within a function group."""
    account_id = current_user.account_id

    proj_result = await session.execute(
        select(Project.id).where(
            Project.id == project_id, Project.account_id == account_id
        )
    )
    if not proj_result.scalars().first():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Project not found"
        )

    # Verify function group belongs to project
    fg_result = await session.execute(
        select(ProjectFunctionGroup.id).where(
            ProjectFunctionGroup.id == fg_id,
            ProjectFunctionGroup.project_id == project_id,
        )
    )
    if not fg_result.scalars().first():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Function group not found"
        )

    base_q = select(ProjectFunction).where(ProjectFunction.function_group_id == fg_id)
    count_q = select(func.count()).select_from(base_q.subquery())
    total = (await session.execute(count_q)).scalar() or 0

    q = (
        base_q.order_by(ProjectFunction.sort_order)
        .offset((page - 1) * size)
        .limit(size)
    )
    result = await session.execute(q)
    items = result.scalars().all()

    return ProjectFunctionListResponse(
        items=[ProjectFunctionResponse.model_validate(i) for i in items],
        total=total,
        page=page,
        size=size,
    )


@router.post(
    "/{project_id}/function-groups/{fg_id}/functions",
    response_model=ProjectFunctionResponse,
    status_code=status.HTTP_201_CREATED,
)
async def create_project_function(
    project_id: str,
    fg_id: str,
    body: ProjectFunctionCreateRequest,
    current_user: User = Depends(require_permission("projects:write")),
    session: AsyncSession = Depends(get_async_session),
):
    """Create a function within a function group."""
    account_id = current_user.account_id

    proj_result = await session.execute(
        select(Project.id).where(
            Project.id == project_id, Project.account_id == account_id
        )
    )
    if not proj_result.scalars().first():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Project not found"
        )

    fg_result = await session.execute(
        select(ProjectFunctionGroup.id).where(
            ProjectFunctionGroup.id == fg_id,
            ProjectFunctionGroup.project_id == project_id,
        )
    )
    if not fg_result.scalars().first():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Function group not found"
        )

    func_obj = ProjectFunction(function_group_id=fg_id, **body.model_dump())
    session.add(func_obj)
    await session.commit()
    await session.refresh(func_obj)
    return ProjectFunctionResponse.model_validate(func_obj)


@router.get(
    "/{project_id}/function-groups/{fg_id}/functions/{func_id}",
    response_model=ProjectFunctionResponse,
)
async def get_project_function(
    project_id: str,
    fg_id: str,
    func_id: str,
    current_user: User = Depends(require_permission("projects:read")),
    session: AsyncSession = Depends(get_async_session),
):
    """Get a specific project function."""
    account_id = current_user.account_id

    proj_result = await session.execute(
        select(Project.id).where(
            Project.id == project_id, Project.account_id == account_id
        )
    )
    if not proj_result.scalars().first():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Project not found"
        )

    fg_result = await session.execute(
        select(ProjectFunctionGroup.id).where(
            ProjectFunctionGroup.id == fg_id,
            ProjectFunctionGroup.project_id == project_id,
        )
    )
    if not fg_result.scalars().first():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Function group not found"
        )

    result = await session.execute(
        select(ProjectFunction).where(
            ProjectFunction.id == func_id,
            ProjectFunction.function_group_id == fg_id,
        )
    )
    func_obj = result.scalars().first()
    if not func_obj:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Function not found"
        )
    return ProjectFunctionResponse.model_validate(func_obj)


@router.put(
    "/{project_id}/function-groups/{fg_id}/functions/{func_id}",
    response_model=ProjectFunctionResponse,
)
async def update_project_function(
    project_id: str,
    fg_id: str,
    func_id: str,
    body: ProjectFunctionUpdateRequest,
    current_user: User = Depends(require_permission("projects:write")),
    session: AsyncSession = Depends(get_async_session),
):
    """Update a project function."""
    account_id = current_user.account_id

    proj_result = await session.execute(
        select(Project.id).where(
            Project.id == project_id, Project.account_id == account_id
        )
    )
    if not proj_result.scalars().first():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Project not found"
        )

    fg_result = await session.execute(
        select(ProjectFunctionGroup.id).where(
            ProjectFunctionGroup.id == fg_id,
            ProjectFunctionGroup.project_id == project_id,
        )
    )
    if not fg_result.scalars().first():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Function group not found"
        )

    result = await session.execute(
        select(ProjectFunction).where(
            ProjectFunction.id == func_id,
            ProjectFunction.function_group_id == fg_id,
        )
    )
    func_obj = result.scalars().first()
    if not func_obj:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Function not found"
        )

    update_data = body.model_dump(exclude_unset=True)
    for field, value in update_data.items():
        setattr(func_obj, field, value)

    await session.commit()
    await session.refresh(func_obj)
    return ProjectFunctionResponse.model_validate(func_obj)


@router.delete(
    "/{project_id}/function-groups/{fg_id}/functions/{func_id}",
    status_code=status.HTTP_204_NO_CONTENT,
)
async def delete_project_function(
    project_id: str,
    fg_id: str,
    func_id: str,
    current_user: User = Depends(require_permission("projects:delete")),
    session: AsyncSession = Depends(get_async_session),
):
    """Delete a project function."""
    account_id = current_user.account_id

    proj_result = await session.execute(
        select(Project.id).where(
            Project.id == project_id, Project.account_id == account_id
        )
    )
    if not proj_result.scalars().first():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Project not found"
        )

    fg_result = await session.execute(
        select(ProjectFunctionGroup.id).where(
            ProjectFunctionGroup.id == fg_id,
            ProjectFunctionGroup.project_id == project_id,
        )
    )
    if not fg_result.scalars().first():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Function group not found"
        )

    result = await session.execute(
        select(ProjectFunction).where(
            ProjectFunction.id == func_id,
            ProjectFunction.function_group_id == fg_id,
        )
    )
    func_obj = result.scalars().first()
    if not func_obj:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Function not found"
        )

    await session.delete(func_obj)
    await session.commit()
    return None