// Copyright 2018 The Nakama Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package server

import (
	"context"
	"github.com/gofrs/uuid"
	"github.com/heroiclabs/nakama-common/api"
	"go.uber.org/zap"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
)

func (s *ApiServer) ListMatches(ctx context.Context, in *api.ListMatchesRequest) (*api.MatchList, error) {
	// Before hook.
	if fn := s.runtime.BeforeListMatches(); fn != nil {
		beforeFn := func(clientIP, clientPort string) error {
			result, err, code := fn(ctx, s.logger, ctx.Value(ctxUserIDKey{}).(uuid.UUID).String(), ctx.Value(ctxUsernameKey{}).(string), ctx.Value(ctxVarsKey{}).(map[string]string), ctx.Value(ctxExpiryKey{}).(int64), clientIP, clientPort, in)
			if err != nil {
				return status.Error(code, err.Error())
			}
			if result == nil {
				// If result is nil, requested resource is disabled.
				s.logger.Warn("Intercepted a disabled resource.", zap.Any("resource", ctx.Value(ctxFullMethodKey{}).(string)), zap.String("uid", ctx.Value(ctxUserIDKey{}).(uuid.UUID).String()))
				return status.Error(codes.NotFound, "Requested resource was not found.")
			}
			in = result
			return nil
		}

		// Execute the before function lambda wrapped in a trace for stats measurement.
		err := traceApiBefore(ctx, s.logger, s.metrics, ctx.Value(ctxFullMethodKey{}).(string), beforeFn)
		if err != nil {
			return nil, err
		}
	}

	limit := 10
	if in.GetLimit() != nil {
		if in.GetLimit().Value < 1 || in.GetLimit().Value > 100 {
			return nil, status.Error(codes.InvalidArgument, "Invalid limit - limit must be between 1 and 100.")
		}
		limit = int(in.GetLimit().Value)
	}

	if in.Label != nil && (in.Authoritative != nil && !in.Authoritative.Value) {
		return nil, status.Error(codes.InvalidArgument, "Label filtering is not supported for non-authoritative matches.")
	}
	if in.Query != nil && (in.Authoritative != nil && !in.Authoritative.Value) {
		return nil, status.Error(codes.InvalidArgument, "Query filtering is not supported for non-authoritative matches.")
	}

	if in.MinSize != nil && in.MinSize.Value < 0 {
		return nil, status.Error(codes.InvalidArgument, "Minimum size must be 0 or above.")
	}
	if in.MaxSize != nil && in.MaxSize.Value < 0 {
		return nil, status.Error(codes.InvalidArgument, "Maximum size must be 0 or above.")
	}
	if in.MinSize != nil && in.MaxSize != nil && in.MinSize.Value > in.MaxSize.Value {
		return nil, status.Error(codes.InvalidArgument, "Maximum size must be greater than or equal to minimum size when both are specified.")
	}

	results, err := s.matchRegistry.ListMatches(ctx, limit, in.Authoritative, in.Label, in.MinSize, in.MaxSize, in.Query)
	if err != nil {
		s.logger.Error("Error listing matches", zap.Error(err))
		return nil, status.Error(codes.Internal, "Error listing matches.")
	}

	list := &api.MatchList{Matches: results}

	// After hook.
	if fn := s.runtime.AfterListMatches(); fn != nil {
		afterFn := func(clientIP, clientPort string) error {
			return fn(ctx, s.logger, ctx.Value(ctxUserIDKey{}).(uuid.UUID).String(), ctx.Value(ctxUsernameKey{}).(string), ctx.Value(ctxVarsKey{}).(map[string]string), ctx.Value(ctxExpiryKey{}).(int64), clientIP, clientPort, list, in)
		}

		// Execute the after function lambda wrapped in a trace for stats measurement.
		traceApiAfter(ctx, s.logger, s.metrics, ctx.Value(ctxFullMethodKey{}).(string), afterFn)
	}

	return list, nil
}
