// Copyright 2024 Kelvin Clement Mwinuka
//
// 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 sugardb

import (
	"bufio"
	"bytes"
	"github.com/echovault/sugardb/internal"
	"github.com/echovault/sugardb/internal/constants"
	"github.com/echovault/sugardb/internal/modules/connection"
	"github.com/tidwall/resp"
	"reflect"
	"testing"
)

func TestSugarDB_Connection(t *testing.T) {
	t.Run("TestSugarDB_Hello", func(t *testing.T) {
		t.Parallel()

		port, err := internal.GetFreePort()
		if err != nil {
			t.Error(err)
			return
		}

		conf := DefaultConfig()
		conf.Port = uint16(port)
		conf.RequirePass = false

		mockServer := createSugarDBWithConfig(conf)
		if err != nil {
			t.Error(err)
			return
		}
		go func() {
			mockServer.Start()
		}()
		t.Cleanup(func() {
			mockServer.ShutDown()
		})

		tests := []struct {
			name    string
			command []resp.Value
			wantRes []byte
		}{
			{
				name:    "1. Hello",
				command: []resp.Value{resp.StringValue("HELLO")},
				wantRes: connection.BuildHelloResponse(
					internal.ServerInfo{
						Server:  "sugardb",
						Version: constants.Version,
						Id:      "",
						Mode:    "standalone",
						Role:    "master",
						Modules: mockServer.ListModules(),
					},
					internal.ConnectionInfo{
						Id:       1,
						Name:     "",
						Protocol: 2,
						Database: 0,
					},
				),
			},
			{
				name:    "2. Hello 2",
				command: []resp.Value{resp.StringValue("HELLO"), resp.StringValue("2")},
				wantRes: connection.BuildHelloResponse(
					internal.ServerInfo{
						Server:  "sugardb",
						Version: constants.Version,
						Id:      "",
						Mode:    "standalone",
						Role:    "master",
						Modules: mockServer.ListModules(),
					},
					internal.ConnectionInfo{
						Id:       2,
						Name:     "",
						Protocol: 2,
						Database: 0,
					},
				),
			},
			{
				name:    "3. Hello 3",
				command: []resp.Value{resp.StringValue("HELLO"), resp.StringValue("3")},
				wantRes: connection.BuildHelloResponse(
					internal.ServerInfo{
						Server:  "sugardb",
						Version: constants.Version,
						Id:      "",
						Mode:    "standalone",
						Role:    "master",
						Modules: mockServer.ListModules(),
					},
					internal.ConnectionInfo{
						Id:       3,
						Name:     "",
						Protocol: 3,
						Database: 0,
					},
				),
			},
		}

		for i := 0; i < len(tests); i++ {
			conn, err := internal.GetConnection("localhost", port)
			if err != nil {
				t.Error(err)
				return
			}
			client := resp.NewConn(conn)

			if err = client.WriteArray(tests[i].command); err != nil {
				t.Error(err)
				return
			}

			buf := bufio.NewReader(conn)
			res, err := internal.ReadMessage(buf)
			if err != nil {
				t.Error(err)
				return
			}

			if !bytes.Equal(tests[i].wantRes, res) {
				t.Errorf("expected byte resposne:\n%s, \n\ngot:\n%s", string(tests[i].wantRes), string(res))
				return
			}

			// Close connection
			_ = conn.Close()
		}
	})

	t.Run("TestSugarDB_SelectDB", func(t *testing.T) {
		t.Parallel()
		tests := []struct {
			name         string
			presetValues map[int]map[string]string
			database     int
			want         map[int][]string
			wantErr      bool
		}{
			{
				name: "1. Change database and read new values",
				presetValues: map[int]map[string]string{
					0: {"key1": "value-01", "key2": "value-02", "key3": "value-03"},
					1: {"key1": "value-11", "key2": "value-12", "key3": "value-13"},
				},
				database: 1,
				want: map[int][]string{
					0: {"value-01", "value-02", "value-03"},
					1: {"value-11", "value-12", "value-13"},
				},
				wantErr: false,
			},
			{
				name: "2. Error when database parameter is < 0",
				presetValues: map[int]map[string]string{
					0: {"key1": "value-01", "key2": "value-02", "key3": "value-03"},
				},
				database: -1,
				want: map[int][]string{
					0: {"value-01", "value-02", "value-03"},
				},
				wantErr: true,
			},
		}
		for _, tt := range tests {
			t.Run(tt.name, func(t *testing.T) {
				t.Parallel()

				server := createSugarDB()
				t.Cleanup(func() {
					server.ShutDown()
				})

				if tt.presetValues != nil {
					for db, data := range tt.presetValues {
						_ = server.SelectDB(db)
						if _, err := server.MSet(data); err != nil {
							t.Errorf("SelectDB() error = %v", err)
							return
						}
					}
					_ = server.SelectDB(0)
				}

				// Check the values for DB 0
				values, err := server.MGet("key1", "key2", "key3")
				if err != nil {
					t.Errorf("SelectDB() error = %v", err)
					return
				}

				if !reflect.DeepEqual(values, tt.want[0]) {
					t.Errorf("SelectDB() result-0 = %v, want-0 %v", values, tt.want[0])
					return
				}

				err = server.SelectDB(tt.database)
				if tt.wantErr {
					if err == nil {
						t.Errorf("SelectDB() error = %v, wantErr %v", err, tt.wantErr)
						return
					}
					return
				}
				if err != nil {
					t.Errorf("SelectDB() error = %v, wantErr %v", err, tt.wantErr)
					return
				}

				// Check the values the new DB
				values, err = server.MGet("key1", "key2", "key3")
				if err != nil {
					t.Errorf("SelectDB() error = %v", err)
					return
				}

				if !reflect.DeepEqual(values, tt.want[1]) {
					t.Errorf("SelectDB() result-1 = %v, want-1 %v", values, tt.want[1])
					return
				}
			})
		}
	})

	t.Run("TestSugarDB_SetProtocol", func(t *testing.T) {
		t.Parallel()

		server := createSugarDB()
		t.Cleanup(func() {
			server.ShutDown()
		})

		tests := []struct {
			name     string
			protocol int
			wantErr  bool
		}{
			{
				name:     "1. Change protocol to 2",
				protocol: 2,
				wantErr:  false,
			},
			{
				name:     "2. Change protocol to 3",
				protocol: 3,
				wantErr:  false,
			},
			{
				name:     "3. Return error when protocol is neither 2 or 3",
				protocol: 4,
				wantErr:  true,
			},
		}
		for _, tt := range tests {
			t.Run(tt.name, func(t *testing.T) {
				err := server.SetProtocol(tt.protocol)
				if tt.wantErr {
					if err == nil {
						t.Errorf("SetProtocol() error = %v, wantErr %v", err, tt.wantErr)
						return
					}
					return
				}
				if err != nil {
					t.Errorf("SetProtocol() error = %v, wantErr %v", err, tt.wantErr)
					return
				}
				// Check if the protocol has been changed
				if server.connInfo.embedded.Protocol != tt.protocol {
					t.Errorf("SetProtocol() protocol = %v, wantProtocol %v",
						server.connInfo.embedded.Protocol, tt.protocol)
				}
			})
		}
	})
}