#
# Copyright (C) 2015 GNS3 Technologies Inc.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

"""
API routes for projects.
"""

import os
import shutil
import urllib.parse
import inspect
import asyncio

import logging

log = logging.getLogger()

from fastapi import APIRouter, Depends, HTTPException, Request, Response, status, Query
from fastapi.encoders import jsonable_encoder
from fastapi.responses import FileResponse
from typing import List
from uuid import UUID

from gns3server.compute.project_manager import ProjectManager
from gns3server.compute.project import Project
from gns3server.compute.base_manager import BaseManager
from gns3server.utils.path import is_safe_path
from gns3server import schemas


router = APIRouter()

# How many clients have subscribed to notifications
_notifications_listening = {}


def dep_project(project_id: UUID) -> Project:
    """
    Dependency to retrieve a project.
    """

    pm = ProjectManager.instance()
    project = pm.get_project(str(project_id))
    return project


@router.get("/projects", response_model=List[schemas.Project])
def get_compute_projects() -> List[schemas.Project]:
    """
    Get all projects opened on the compute.
    """

    pm = ProjectManager.instance()
    return [p.asdict() for p in pm.projects]


@router.post("/projects", status_code=status.HTTP_201_CREATED, response_model=schemas.Project)
def create_compute_project(project_data: schemas.ProjectCreate) -> schemas.Project:
    """
    Create a new project on the compute.
    """

    pm = ProjectManager.instance()
    project_data = jsonable_encoder(project_data, exclude_unset=True)
    project = pm.create_project(
        name=project_data.get("name"),
        path=project_data.get("path"),
        project_id=project_data.get("project_id"),
        variables=project_data.get("variables", None),
    )
    return project.asdict()


@router.put("/projects/{project_id}", response_model=schemas.Project)
async def update_compute_project(
        project_data: schemas.ProjectUpdate,
        project: Project = Depends(dep_project)
) -> schemas.Project:
    """
    Update project on the compute.
    """

    await project.update(variables=project_data.variables)
    return project.asdict()


@router.get("/projects/{project_id}", response_model=schemas.Project)
def get_compute_project(project: Project = Depends(dep_project)) -> schemas.Project:
    """
    Return a project from the compute.
    """

    return project.asdict()


@router.post("/projects/{project_id}/close", status_code=status.HTTP_204_NO_CONTENT)
async def close_compute_project(project: Project = Depends(dep_project)) -> None:
    """
    Close a project on the compute.
    """

    # FIXME
    if _notifications_listening.setdefault(project.id, 0) <= 1:
        await project.close()
        ProjectManager.instance().remove_project(project.id)
        try:
            del _notifications_listening[project.id]
        except KeyError:
            pass
    else:
        log.warning("Skip project closing, another client is listening for project notifications")


@router.delete("/projects/{project_id}", status_code=status.HTTP_204_NO_CONTENT)
async def delete_compute_project(project: Project = Depends(dep_project)) -> None:
    """
    Delete project from the compute.
    """

    await project.delete()
    ProjectManager.instance().remove_project(project.id)


async def _add_nio_binding(node, adapter_number, port_number, nio):
    """
    Unified NIO-binding dispatch across node types.  Each node type exposes a
    different method signature, so centralise the fan-out here for the batch
    endpoint. Dispatch keys off the manager class name (only dynamips/iou/qemu
    carry a ``_NODE_TYPE`` attribute, so it can't be used universally).
    """

    manager_name = type(node.manager).__name__
    # Adapter-based nodes: docker / qemu / vmware / virtualbox take
    # (adapter_number, nio); iou additionally takes port_number.
    if manager_name in ("Docker", "Qemu", "VMware", "VirtualBox"):
        await node.adapter_add_nio_binding(adapter_number, nio)
    elif manager_name == "IOU":
        await node.adapter_add_nio_binding(adapter_number, port_number, nio)
    elif manager_name == "VPCS":
        await node.port_add_nio_binding(port_number, nio)
    elif manager_name == "Dynamips":
        # Dynamips routers use slot_add_nio_binding(slot, port, nio);
        # Dynamips switches/hubs use add_nio(nio, port_number).
        if hasattr(node, "slot_add_nio_binding"):
            await node.slot_add_nio_binding(adapter_number, port_number, nio)
        else:
            await node.add_nio(nio, port_number)
    elif manager_name == "Builtin":
        # ethernet_switch / ethernet_hub / cloud / nat: add_nio(nio, port_number)
        await node.add_nio(nio, port_number)
    else:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=f"Batch NIO creation not supported for node type '{manager_name}'",
        )


def _get_existing_nio(node, adapter_number, port_number):
    """
    Fetch the already-bound NIO for a port, preserving its UDP endpoints
    (lport/rhost/rport) so a marker/filter update only changes markers/filters.
    Dispatch keys off the manager class name, mirroring _add_nio_binding.
    """

    manager_name = type(node.manager).__name__
    if manager_name in ("Docker", "Qemu", "VMware", "VirtualBox"):
        return node.get_nio(adapter_number)
    elif manager_name == "IOU":
        return node.get_nio(adapter_number, port_number)
    elif manager_name in ("VPCS", "Builtin"):
        return node.get_nio(port_number)
    elif manager_name == "Dynamips":
        # Dynamips routers expose NIOs via the slot/adapter; switches/hubs
        # via get_nio(port).
        if hasattr(node, "get_nio"):
            import inspect as _inspect
            if len(_inspect.signature(node.get_nio).parameters) >= 2:
                return node.get_nio(adapter_number, port_number)
            return node.get_nio(port_number)
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=f"Dynamips node '{node.name}' has no get_nio for batch update",
        )
    raise HTTPException(
        status_code=status.HTTP_400_BAD_REQUEST,
        detail=f"Batch NIO update not supported for node type '{manager_name}'",
    )


async def _update_nio_binding(node, adapter_number, port_number, nio):
    """
    Re-apply a NIO binding (filters + markers) to a started node's uBridge.
    Dispatch keys off the manager class name, mirroring _add_nio_binding.
    """

    manager_name = type(node.manager).__name__
    if manager_name in ("Docker", "Qemu", "VMware", "VirtualBox"):
        await node.adapter_update_nio_binding(adapter_number, nio)
    elif manager_name == "IOU":
        await node.adapter_update_nio_binding(adapter_number, port_number, nio)
    elif manager_name == "VPCS":
        await node.port_update_nio_binding(port_number, nio)
    elif manager_name == "Dynamips":
        if hasattr(node, "slot_update_nio_binding"):
            await node.slot_update_nio_binding(adapter_number, port_number, nio)
        else:
            await node.update_nio(port_number, nio)
    elif manager_name == "Builtin":
        await node.update_nio(port_number, nio)
    else:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=f"Batch NIO update not supported for node type '{manager_name}'",
        )


@router.post(
    "/projects/{project_id}/nios/batch",
    status_code=status.HTTP_201_CREATED,
)
async def create_batch_nios(
        project_id: UUID,
        batch: schemas.BatchNIOCreate,
        project: Project = Depends(dep_project),
) -> dict:
    """
    Create many NIO bindings across nodes in a single request.

    Used by the controller during project open to avoid one HTTP round-trip per
    NIO. Each entry resolves its node via the project, builds the NIO through
    the node's manager, and binds it. Nodes that are not started perform the
    binding in memory; started nodes additionally wire uBridge.
    """

    # Group entries by node so different nodes' uBridge processes are wired
    # in parallel (each node has its own AF_UNIX socket). Within a node
    # entries are serial to respect the per-node uBridge command lock.
    # This is what makes builtin L2 nodes (ethernet_switch/hub/cloud/nat)
    # start their uBridge concurrently during project open instead of one
    # at a time (~0.5s each for fork + socket connect).
    per_node = {}
    for entry in batch.nios:
        per_node.setdefault(entry.node_id, []).append(entry)

    async def _create_one_node(node_id, entries):
        node = project.get_node(node_id)
        # Dynamips.create_nio(self, node, nio_settings) is async and takes
        # an extra positional 'node'; other managers' create_nio(nio_settings)
        # is synchronous. Detect once per node via bound-method parameter
        # count (standard == 1, Dynamips == 2) and await the async variant.
        sig = inspect.signature(node.manager.create_nio)
        dynamips_style = len(sig.parameters) >= 2
        for entry in entries:
            nio_settings = jsonable_encoder(entry.nio, exclude_unset=True)
            if dynamips_style:
                nio = await node.manager.create_nio(node, nio_settings)
            else:
                nio = node.manager.create_nio(nio_settings)
            await _add_nio_binding(node, entry.adapter_number, entry.port_number, nio)

    await asyncio.gather(
        *[_create_one_node(nid, ents) for nid, ents in per_node.items()]
    )
    return {"added": len(batch.nios)}


@router.put(
    "/projects/{project_id}/nios/batch",
    status_code=status.HTTP_200_OK,
)
async def update_batch_nios(
        project_id: UUID,
        batch: schemas.BatchNIOCreate,
        project: Project = Depends(dep_project),
) -> dict:
    """
    Update many NIO bindings (filters + markers) across nodes in a single
    request, re-applying them to uBridge on started nodes.

    Used by the controller when a project-level marker definition changes and
    must fan out to every affected link — replacing one PUT /nio round-trip per
    link end with one round-trip per compute. Each entry fetches the already-
    bound NIO (preserving its UDP endpoints), overlays the new markers/filters,
    and re-binds it.
    """

    # Group entries by node so that different nodes' uBridge processes are
    # updated in parallel (each node has its own AF_UNIX socket). Within a
    # node entries are serial to respect the per-node uBridge command lock.
    per_node = {}
    for entry in batch.nios:
        per_node.setdefault(entry.node_id, []).append(entry)

    async def _update_one_node(node_id, entries):
        node = project.get_node(node_id)
        for e in entries:
            nio = _get_existing_nio(node, e.adapter_number, e.port_number)
            nio.filters = e.nio.filters or {}
            nio.markers = e.nio.markers or {}
            await _update_nio_binding(node, e.adapter_number, e.port_number, nio)

    await asyncio.gather(
        *[_update_one_node(nid, ents) for nid, ents in per_node.items()]
    )
    return {"updated": len(batch.nios)}


@router.get("/projects/{project_id}/files", response_model=List[schemas.ProjectFile])
async def get_compute_project_files(project: Project = Depends(dep_project)) -> List[schemas.ProjectFile]:
    """
    Return files belonging to a project.
    """

    return await project.list_files()


@router.get("/projects/{project_id}/nodes/{node_type}/{node_id}/files", response_model=List[schemas.NodeFile])
async def get_compute_node_files(
    node_type: str,
    node_id: str,
    project: Project = Depends(dep_project),
    path: str = Query("", description="Subdirectory path within node directory"),
    recursive: bool = Query(False, description="Recursively list all files")
) -> List[schemas.NodeFile]:
    """
    Return files belonging to a specific node with detailed metadata.
    """

    node_path = f"project-files/{node_type}/{node_id}"
    return await project.list_node_files(node_path, subpath=path, recursive=recursive)


@router.get("/projects/{project_id}/files/{file_path:path}")
async def get_compute_project_file(file_path: str, project: Project = Depends(dep_project)) -> FileResponse:
    """
    Get a file from a project.
    """

    file_path = urllib.parse.unquote(file_path)
    path = os.path.normpath(file_path)

    # Raise error if user try to escape
    if not is_safe_path(path, project.path):
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN)

    path = os.path.join(project.path, path)
    if not os.path.exists(path):
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND)

    return FileResponse(path, media_type="application/octet-stream")


@router.post("/projects/{project_id}/files/{file_path:path}", status_code=status.HTTP_204_NO_CONTENT)
async def write_compute_project_file(
        file_path: str,
        request: Request,
        project: Project = Depends(dep_project)
) -> None:

    file_path = urllib.parse.unquote(file_path)
    path = os.path.normpath(file_path)

    # Raise error if user try to escape
    if not is_safe_path(path, project.path):
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Path is outside the project directory")

    path = os.path.join(project.path, path)
    try:
        os.makedirs(os.path.dirname(path), exist_ok=True)

        with open(path, "wb+") as f:
            async for chunk in request.stream():
                f.write(chunk)

    except FileNotFoundError:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND)
    except PermissionError:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail=f"Permission denied writing to '{path}'")
    except OSError as e:
        log.error(f"Error writing file '{path}': {e}")
        raise HTTPException(status_code=status.HTTP_500_INTERNAL_SERVER_ERROR, detail=str(e))


@router.delete("/projects/{project_id}/files/{file_path:path}", status_code=status.HTTP_204_NO_CONTENT)
async def delete_compute_project_file(
        file_path: str,
        project: Project = Depends(dep_project)
) -> None:

    file_path = urllib.parse.unquote(file_path)
    path = os.path.normpath(file_path)

    if not is_safe_path(path, project.path):
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Path is outside the project directory")

    path = os.path.join(project.path, path)
    if not os.path.exists(path):
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND)

    try:
        if os.path.isdir(path):
            shutil.rmtree(path)
        else:
            os.remove(path)
    except FileNotFoundError:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND)
    except PermissionError:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail=f"Permission denied deleting '{path}'")
    except OSError as e:
        raise HTTPException(status_code=status.HTTP_500_INTERNAL_SERVER_ERROR, detail=str(e))