// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
// See the LICENCE file in the repository root for full licence text.

using osu.Framework.Allocation;
using osu.Framework.Graphics;
using osu.Game.Online.Chat;
using osu.Game.Users;
using osuTK;
using System;
using System.Linq;
using NUnit.Framework;
using osu.Framework.Graphics.Containers;
using osu.Game.Graphics.Containers;
using osu.Game.Overlays.Chat;
using osuTK.Input;

namespace osu.Game.Tests.Visual.Online
{
    public class TestSceneStandAloneChatDisplay : OsuManualInputManagerTestScene
    {
        private readonly User admin = new User
        {
            Username = "HappyStick",
            Id = 2,
            Colour = "f2ca34"
        };

        private readonly User redUser = new User
        {
            Username = "BanchoBot",
            Id = 3,
        };

        private readonly User blueUser = new User
        {
            Username = "Zallius",
            Id = 4,
        };

        private readonly User longUsernameUser = new User
        {
            Username = "Very Long Long Username",
            Id = 5,
        };

        [Cached]
        private ChannelManager channelManager = new ChannelManager();

        private TestStandAloneChatDisplay chatDisplay;
        private int messageIdSequence;

        private Channel testChannel;

        public TestSceneStandAloneChatDisplay()
        {
            Add(channelManager);
        }

        [SetUp]
        public void SetUp() => Schedule(() =>
        {
            messageIdSequence = 0;
            channelManager.CurrentChannel.Value = testChannel = new Channel();

            Children = new[]
            {
                chatDisplay = new TestStandAloneChatDisplay
                {
                    Anchor = Anchor.CentreLeft,
                    Origin = Anchor.CentreLeft,
                    Margin = new MarginPadding(20),
                    Size = new Vector2(400, 80),
                    Channel = { Value = testChannel },
                },
                new TestStandAloneChatDisplay(true)
                {
                    Anchor = Anchor.CentreRight,
                    Origin = Anchor.CentreRight,
                    Margin = new MarginPadding(20),
                    Size = new Vector2(400, 150),
                    Channel = { Value = testChannel },
                }
            };
        });

        [Test]
        public void TestManyMessages()
        {
            AddStep("message from admin", () => testChannel.AddNewMessages(new Message(messageIdSequence++)
            {
                Sender = admin,
                Content = "I am a wang!"
            }));

            AddStep("message from team red", () => testChannel.AddNewMessages(new Message(messageIdSequence++)
            {
                Sender = redUser,
                Content = "I am team red."
            }));

            AddStep("message from team red", () => testChannel.AddNewMessages(new Message(messageIdSequence++)
            {
                Sender = redUser,
                Content = "I plan to win!"
            }));

            AddStep("message from team blue", () => testChannel.AddNewMessages(new Message(messageIdSequence++)
            {
                Sender = blueUser,
                Content = "Not on my watch. Prepare to eat saaaaaaaaaand. Lots and lots of saaaaaaand."
            }));

            AddStep("message from admin", () => testChannel.AddNewMessages(new Message(messageIdSequence++)
            {
                Sender = admin,
                Content = "Okay okay, calm down guys. Let's do this!"
            }));

            AddStep("message from long username", () => testChannel.AddNewMessages(new Message(messageIdSequence++)
            {
                Sender = longUsernameUser,
                Content = "Hi guys, my new username is lit!"
            }));

            AddStep("message with new date", () => testChannel.AddNewMessages(new Message(messageIdSequence++)
            {
                Sender = longUsernameUser,
                Content = "Message from the future!",
                Timestamp = DateTimeOffset.Now
            }));

            checkScrolledToBottom();

            const int messages_per_call = 10;
            AddRepeatStep("add many messages", () =>
            {
                for (int i = 0; i < messages_per_call; i++)
                {
                    testChannel.AddNewMessages(new Message(messageIdSequence++)
                    {
                        Sender = longUsernameUser,
                        Content = "Many messages! " + Guid.NewGuid(),
                        Timestamp = DateTimeOffset.Now
                    });
                }
            }, Channel.MAX_HISTORY / messages_per_call + 5);

            AddAssert("Ensure no adjacent day separators", () =>
            {
                var indices = chatDisplay.FillFlow.OfType<DrawableChannel.DaySeparator>().Select(ds => chatDisplay.FillFlow.IndexOf(ds));

                foreach (var i in indices)
                {
                    if (i < chatDisplay.FillFlow.Count && chatDisplay.FillFlow[i + 1] is DrawableChannel.DaySeparator)
                        return false;
                }

                return true;
            });

            checkScrolledToBottom();
        }

        /// <summary>
        /// Tests that when a message gets wrapped by the chat display getting contracted while scrolled to bottom, the chat will still keep scrolling down.
        /// </summary>
        [Test]
        public void TestMessageWrappingKeepsAutoScrolling()
        {
            fillChat();

            // send message with short words for text wrapping to occur when contracting chat.
            sendMessage();

            AddStep("contract chat", () => chatDisplay.Width -= 100);
            checkScrolledToBottom();

            AddStep("send another message", () => testChannel.AddNewMessages(new Message(messageIdSequence++)
            {
                Sender = admin,
                Content = "As we were saying...",
            }));

            checkScrolledToBottom();
        }

        [Test]
        public void TestUserScrollOverride()
        {
            fillChat();

            sendMessage();
            checkScrolledToBottom();

            AddStep("User scroll up", () =>
            {
                InputManager.MoveMouseTo(chatDisplay.ScreenSpaceDrawQuad.Centre);
                InputManager.PressButton(MouseButton.Left);
                InputManager.MoveMouseTo(chatDisplay.ScreenSpaceDrawQuad.Centre + new Vector2(0, chatDisplay.ScreenSpaceDrawQuad.Height));
                InputManager.ReleaseButton(MouseButton.Left);
            });

            checkNotScrolledToBottom();
            sendMessage();
            checkNotScrolledToBottom();

            AddRepeatStep("User scroll to bottom", () =>
            {
                InputManager.MoveMouseTo(chatDisplay.ScreenSpaceDrawQuad.Centre);
                InputManager.PressButton(MouseButton.Left);
                InputManager.MoveMouseTo(chatDisplay.ScreenSpaceDrawQuad.Centre - new Vector2(0, chatDisplay.ScreenSpaceDrawQuad.Height));
                InputManager.ReleaseButton(MouseButton.Left);
            }, 5);

            checkScrolledToBottom();
            sendMessage();
            checkScrolledToBottom();
        }

        private void fillChat()
        {
            AddStep("fill chat", () =>
            {
                for (int i = 0; i < 10; i++)
                {
                    testChannel.AddNewMessages(new Message(messageIdSequence++)
                    {
                        Sender = longUsernameUser,
                        Content = $"some stuff {Guid.NewGuid()}",
                    });
                }
            });

            checkScrolledToBottom();
        }

        private void sendMessage()
        {
            AddStep("send lorem ipsum", () => testChannel.AddNewMessages(new Message(messageIdSequence++)
            {
                Sender = longUsernameUser,
                Content = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Fusce et bibendum velit.",
            }));
        }

        private void checkScrolledToBottom() =>
            AddUntilStep("is scrolled to bottom", () => chatDisplay.ScrolledToBottom);

        private void checkNotScrolledToBottom() =>
            AddUntilStep("not scrolled to bottom", () => !chatDisplay.ScrolledToBottom);

        private class TestStandAloneChatDisplay : StandAloneChatDisplay
        {
            public TestStandAloneChatDisplay(bool textbox = false)
                : base(textbox)
            {
            }

            protected DrawableChannel DrawableChannel => InternalChildren.OfType<DrawableChannel>().First();

            protected UserTrackingScrollContainer ScrollContainer => (UserTrackingScrollContainer)((Container)DrawableChannel.Child).Child;

            public FillFlowContainer FillFlow => (FillFlowContainer)ScrollContainer.Child;

            public bool ScrolledToBottom => ScrollContainer.IsScrolledToEnd(1);
        }
    }
}