// Copyright (c) Argo Zhang (argo@163.com). All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
// Website: https://www.blazor.zone or https://argozhang.github.io/

using Microsoft.AspNetCore.Components;
using Microsoft.Extensions.Localization;
using Microsoft.JSInterop;
using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace BootstrapBlazor.Components
{
    /// <summary>
    /// 
    /// </summary>
    public partial class Camera : IAsyncDisposable
    {
        private ElementReference CameraElement { get; set; }

        private JSInterop<Camera>? Interop { get; set; }

        private string DeviceId { get; set; } = "";

        private bool IsDisabled { get; set; } = true;

        private bool CaptureDisabled { get; set; } = true;

        private IEnumerable<SelectedItem> Devices { get; set; } = Enumerable.Empty<SelectedItem>();

        [NotNull]
        private IEnumerable<SelectedItem>? Cameras { get; set; }

        private SelectedItem? ActiveCamera { get; set; }

        /// <summary>
        /// 获得/设置 是否自动开启摄像头 默认为 false
        /// </summary>
        [Parameter]
        public bool AutoStart { get; set; }

        /// <summary>
        /// 获得/设置 前置摄像头显示文本 默认前置
        /// </summary>
        [Parameter]
        [NotNull]
        public string? FrontText { get; set; }

        /// <summary>
        /// 获得/设置 后置摄像头显示文本 默认后置
        /// </summary>
        [Parameter]
        [NotNull]
        public string? BackText { get; set; }

        /// <summary>
        /// 获得/设置 是否显示 照片预览 默认为 false 不预览
        /// </summary>
        [Parameter]
        public bool ShowPreview { get; set; }

        /// <summary>
        /// 获得/设置 设备列表前置标签文字 默认为 摄像头
        /// </summary>
        [Parameter]
        [NotNull]
        public string? DeviceLabel { get; set; }

        /// <summary>
        /// 获得/设置 初始化设备列表文字 默认为 正在识别摄像头
        /// </summary>
        [Parameter]
        [NotNull]
        public string? InitDevicesString { get; set; }

        /// <summary>
        /// 获得/设置 初始化摄像头回调方法
        /// </summary>
        [Parameter]
        public Func<IEnumerable<DeviceItem>, Task>? OnInit { get; set; }

        /// <summary>
        /// 获得/设置 扫码出错回调方法
        /// </summary>
        [Parameter]
        public Func<string, Task>? OnError { get; set; }

        /// <summary>
        /// 获得/设置 开始扫码回调方法
        /// </summary>
        [Parameter]
        public Func<Task>? OnStart { get; set; }

        /// <summary>
        /// 获得/设置 关闭扫码回调方法
        /// </summary>
        [Parameter]
        public Func<Task>? OnClose { get; set; }

        /// <summary>
        /// 获得/设置 扫码成功回调方法
        /// </summary>
        [Parameter]
        public Func<string, Task>? OnCapture { get; set; }

        /// <summary>
        /// 获得/设置 开启按钮显示文本 默认为开启
        /// </summary>
        [NotNull]
        [Parameter]
        public string? PlayText { get; set; }

        /// <summary>
        /// 获得/设置 关闭按钮显示文本 默认为关闭
        /// </summary>
        [NotNull]
        [Parameter]
        public string? StopText { get; set; }

        /// <summary>
        /// 获得/设置 拍照按钮显示文本 默认为拍照
        /// </summary>
        [NotNull]
        [Parameter]
        public string? PhotoText { get; set; }

        /// <summary>
        /// 获得/设置 未找到视频相关设备文字 默认为 未找到视频相关设备
        /// </summary>
        [Parameter]
        [NotNull]
        public string? NotFoundDevicesString { get; set; }

        [Inject]
        [NotNull]
        private IStringLocalizer<Camera>? Localizer { get; set; }

        /// <summary>
        /// OnInitialized 方法
        /// </summary>
        protected override void OnInitialized()
        {
            base.OnInitialized();

            PlayText ??= Localizer[nameof(PlayText)];
            StopText ??= Localizer[nameof(StopText)];
            PhotoText ??= Localizer[nameof(PhotoText)];
            DeviceLabel ??= Localizer[nameof(DeviceLabel)];
            InitDevicesString ??= Localizer[nameof(InitDevicesString)];
            NotFoundDevicesString ??= Localizer[nameof(NotFoundDevicesString)];
            FrontText ??= Localizer[nameof(FrontText)];
            BackText ??= Localizer[nameof(BackText)];

            Cameras = new SelectedItem[]
            {
                new SelectedItem { Text = FrontText!, Value = "user", Active = true },
                new SelectedItem { Text = BackText!, Value = "environment" }
            };
        }

        /// <summary>
        /// OnAfterRenderAsync 方法
        /// </summary>
        /// <param name="firstRender"></param>
        /// <returns></returns>
        protected override async Task OnAfterRenderAsync(bool firstRender)
        {
            await base.OnAfterRenderAsync(firstRender);

            if (firstRender && JSRuntime != null)
            {
                Interop = new JSInterop<Camera>(JSRuntime);
                await Interop.InvokeVoidAsync(this, CameraElement, "bb_camera", "init", AutoStart);
            }
        }

        /// <summary>
        /// 初始化设备方法
        /// </summary>
        /// <param name="devices"></param>
        /// <returns></returns>
        [JSInvokable]
        public async Task InitDevices(IEnumerable<DeviceItem> devices)
        {
            Devices = devices.Select(i => new SelectedItem { Value = i.DeviceId, Text = i.Label });
            IsDisabled = !Devices.Any();

            if (OnInit != null)
            {
                await OnInit(devices);
            }

            if (devices.Any())
            {
                for (var index = 0; index < devices.Count(); index++)
                {
                    var d = devices.ElementAt(index);
                    if (string.IsNullOrEmpty(d.Label))
                    {
                        d.Label = $"Video device {index + 1}";
                    }
                }
                IsDisabled = false;
                ActiveCamera = Cameras.First();
            }

            if (IsDisabled)
            {
                InitDevicesString = NotFoundDevicesString;
            }

            StateHasChanged();
        }

        /// <summary>
        /// 扫描发生错误回调方法
        /// </summary>
        /// <param name="err"></param>
        /// <returns></returns>
        [JSInvokable]
        public async Task GetError(string err)
        {
            if (OnError != null)
            {
                await OnError.Invoke(err);
            }
        }

        /// <summary>
        /// 开启摄像头回调方法
        /// </summary>
        /// <returns></returns>
        [JSInvokable]
        public async Task Start()
        {
            CaptureDisabled = false;
            if (OnStart != null)
            {
                await OnStart.Invoke();
            }

            StateHasChanged();
        }

        /// <summary>
        /// 停止摄像头回调方法
        /// </summary>
        /// <returns></returns>
        [JSInvokable]
        public async Task Stop()
        {
            CaptureDisabled = true;
            if (OnClose != null)
            {
                await OnClose.Invoke();
            }

            StateHasChanged();
        }

        private readonly StringBuilder _sb = new();
        /// <summary>
        /// 拍照回调方法
        /// </summary>
        /// <returns></returns>
        [JSInvokable]
        public async Task Capture(string payload)
        {
            if (payload == "__BB__%END%__BB__")
            {
                var data = _sb.ToString();
                _sb.Clear();
                if (OnCapture != null)
                {
                    await OnCapture(data);
                }
            }
            else
            {
                _sb.Append(payload);
            }
        }

        /// <summary>
        /// DisposeAsyncCore 方法
        /// </summary>
        /// <param name="disposing"></param>
        /// <returns></returns>
        protected virtual async ValueTask DisposeAsyncCore(bool disposing)
        {
            if (disposing && Interop != null)
            {
                await JSRuntime.InvokeVoidAsync(CameraElement, "bb_camera", "", "stop").ConfigureAwait(false);
                Interop.Dispose();
                Interop = null;
            }
        }

        /// <summary>
        /// DisposeAsync 方法
        /// </summary>
        public async ValueTask DisposeAsync()
        {
            await DisposeAsyncCore(true).ConfigureAwait(false);
            GC.SuppressFinalize(this);
        }
    }
}
