package clientapi

import (
	"net/http"
	"strconv"

	"github.com/dariuszjaniak/warp/server/internal/httputil"
	"github.com/dariuszjaniak/warp/server/internal/roomserver"
	"github.com/dariuszjaniak/warp/server/internal/userapi"
)

// aliasResponse is the GET /directory/room/{roomAlias} body.
type aliasResponse struct {
	RoomID  string   `json:"room_id"`
	Servers []string `json:"servers"`
}

// handleGetAlias implements GET /_matrix/client/v3/directory/room/{roomAlias}.
//
// The endpoint needs no token: a client that has been handed a link has to
// be able to turn it into a room ID before it can decide whether to log in,
// and the spec makes it unauthenticated for that reason.
func (c *ClientAPI) handleGetAlias(w http.ResponseWriter, r *http.Request) error {
	alias, err := aliasFromPath(r)
	if err != nil {
		return err
	}
	resolved, err := c.rooms.ResolveAlias(r.Context(), alias)
	if err != nil {
		return roomError(err)
	}
	httputil.WriteJSON(w, http.StatusOK, aliasResponse{
		RoomID:  resolved.RoomID,
		Servers: resolved.Servers,
	})
	return nil
}

// putAliasRequest is the PUT /directory/room/{roomAlias} body.
type putAliasRequest struct {
	RoomID string `json:"room_id"`
}

// handlePutAlias implements PUT /_matrix/client/v3/directory/room/{roomAlias}.
func (c *ClientAPI) handlePutAlias(w http.ResponseWriter, r *http.Request, auth userapi.Authenticated) error {
	alias, err := aliasFromPath(r)
	if err != nil {
		return err
	}
	var req putAliasRequest
	if err := httputil.DecodeJSON(w, r, &req); err != nil {
		return err
	}
	if req.RoomID == "" {
		return httputil.MissingParam("A room ID is required")
	}

	if err := c.rooms.CreateAlias(r.Context(), alias, req.RoomID, auth.UserID); err != nil {
		return roomError(err)
	}
	httputil.WriteJSON(w, http.StatusOK, struct{}{})
	return nil
}

// handleDeleteAlias implements
// DELETE /_matrix/client/v3/directory/room/{roomAlias}.
func (c *ClientAPI) handleDeleteAlias(w http.ResponseWriter, r *http.Request, auth userapi.Authenticated) error {
	alias, err := aliasFromPath(r)
	if err != nil {
		return err
	}
	if err := c.rooms.DeleteAlias(r.Context(), alias, auth.UserID, auth.Admin); err != nil {
		return roomError(err)
	}
	httputil.WriteJSON(w, http.StatusOK, struct{}{})
	return nil
}

// roomAliasesResponse is the GET /rooms/{roomID}/aliases body.
type roomAliasesResponse struct {
	Aliases []string `json:"aliases"`
}

// handleGetRoomAliases implements
// GET /_matrix/client/v3/rooms/{roomID}/aliases.
func (c *ClientAPI) handleGetRoomAliases(w http.ResponseWriter, r *http.Request, auth userapi.Authenticated) error {
	roomID, err := pathRoomID(r)
	if err != nil {
		return err
	}
	aliases, err := c.rooms.RoomAliases(r.Context(), roomID, auth.UserID)
	if err != nil {
		return roomError(err)
	}
	httputil.WriteJSON(w, http.StatusOK, roomAliasesResponse{Aliases: aliases})
	return nil
}

// visibilityResponse is the GET /directory/list/room/{roomID} body.
type visibilityResponse struct {
	Visibility string `json:"visibility"`
}

// handleGetRoomVisibility implements
// GET /_matrix/client/v3/directory/list/room/{roomID}.
//
// Whether a room is in the public directory is itself public: the directory
// can be read without a token, so hiding the flag behind one would protect
// nothing.
func (c *ClientAPI) handleGetRoomVisibility(w http.ResponseWriter, r *http.Request) error {
	roomID, err := pathRoomID(r)
	if err != nil {
		return err
	}
	visibility, err := c.rooms.RoomVisibility(r.Context(), roomID)
	if err != nil {
		return roomError(err)
	}
	httputil.WriteJSON(w, http.StatusOK, visibilityResponse{Visibility: visibility})
	return nil
}

// handlePutRoomVisibility implements
// PUT /_matrix/client/v3/directory/list/room/{roomID}.
func (c *ClientAPI) handlePutRoomVisibility(w http.ResponseWriter, r *http.Request, auth userapi.Authenticated) error {
	roomID, err := pathRoomID(r)
	if err != nil {
		return err
	}
	var req visibilityResponse
	if err := httputil.DecodeJSON(w, r, &req); err != nil {
		return err
	}
	if err := c.rooms.SetRoomVisibility(r.Context(), roomID, auth.UserID, req.Visibility, auth.Admin); err != nil {
		return roomError(err)
	}
	httputil.WriteJSON(w, http.StatusOK, struct{}{})
	return nil
}

// publicRoomsFilter is the filter in a POST /publicRooms body.
type publicRoomsFilter struct {
	GenericSearchTerm string   `json:"generic_search_term"`
	RoomTypes         []string `json:"room_types"`
}

// publicRoomsRequest is the POST /publicRooms body.
type publicRoomsRequest struct {
	Limit  int               `json:"limit"`
	Since  string            `json:"since"`
	Filter publicRoomsFilter `json:"filter"`

	// IncludeAllNetworks and ThirdPartyInstanceID select an application
	// service's own directory, which arrives with application service
	// support in Phase 9.
	IncludeAllNetworks   bool   `json:"include_all_networks"`
	ThirdPartyInstanceID string `json:"third_party_instance_id"`
}

// handleGetPublicRooms implements GET /_matrix/client/v3/publicRooms.
func (c *ClientAPI) handleGetPublicRooms(w http.ResponseWriter, r *http.Request) error {
	query := r.URL.Query()

	limit := 0
	if raw := query.Get("limit"); raw != "" {
		parsed, err := strconv.Atoi(raw)
		if err != nil || parsed < 0 {
			return httputil.InvalidParam("limit must be a non-negative integer")
		}
		limit = parsed
	}

	return c.publicRooms(w, r, roomserver.PublicRoomsRequest{
		Limit:  limit,
		Since:  query.Get("since"),
		Server: query.Get("server"),
	})
}

// handlePostPublicRooms implements POST /_matrix/client/v3/publicRooms,
// which is the same listing with a filter.
func (c *ClientAPI) handlePostPublicRooms(w http.ResponseWriter, r *http.Request, _ userapi.Authenticated) error {
	var req publicRoomsRequest
	if _, err := httputil.DecodeOptionalJSON(w, r, &req); err != nil {
		return err
	}
	if req.ThirdPartyInstanceID != "" {
		return httputil.Unknown(http.StatusBadRequest,
			"Application service room directories are not supported by this server")
	}
	if req.Limit < 0 {
		return httputil.InvalidParam("limit must be a non-negative integer")
	}

	return c.publicRooms(w, r, roomserver.PublicRoomsRequest{
		Limit:  req.Limit,
		Since:  req.Since,
		Search: req.Filter.GenericSearchTerm,
		Server: r.URL.Query().Get("server"),
	})
}

// publicRooms is the body of both directory endpoints.
func (c *ClientAPI) publicRooms(w http.ResponseWriter, r *http.Request, req roomserver.PublicRoomsRequest) error {
	resp, err := c.rooms.PublicRooms(r.Context(), req)
	if err != nil {
		return roomError(err)
	}
	httputil.WriteJSON(w, http.StatusOK, resp)
	return nil
}