using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using Amazon.DynamoDBv2;
using Amazon.DynamoDBv2.DataModel;
using Amazon.DynamoDBv2.DocumentModel;
using Amazon.Runtime;
using static System.Console;
using static ConsoleApp2.Ext;

namespace ConsoleApp2
{
    public static class Ext
    {
        public static IEnumerable<object> L<T>(T one) => new[] {(object) one};
        public static IEnumerable<object> L<T>(T one, T two) => new[] {(object) one, two};
    }

    public static class HighLevelQueryAndScan
    {
        private static readonly AmazonDynamoDBClient Client = new AmazonDynamoDBClient();

        public static async Task Main()
        {
            try
            {
                var context = new DynamoDBContext(Client, new DynamoDBContextConfig()
                {
                    TableNamePrefix = "je-qa29-"
                });

                // Get item.
                await GetBook(context, 101);

                // Sample forum and thread to test queries.
                var forumName = "Amazon DynamoDB";
                var threadSubject = "DynamoDB Thread 1";

                // Sample queries.
                await FindRepliesInLast15Days(context, forumName, threadSubject);
                await FindRepliesPostedWithinTimePeriod(context, forumName, threadSubject);

                // Scan table.
                await FindProductsPricedLessThanZero(context);
                WriteLine("To continue, press Enter");
                ReadLine();
            }
            catch (Exception e)
            {
                WriteLine(e.Message);
            }
        }

        private static async Task GetBook(IDynamoDBContext context, int productId)
        {
            var productItem = await context.LoadAsync<Product>(productId);

            WriteLine("\nGetBook: Printing result.....");
            WriteLine("Title: {0} \n No.Of threads:{1} \n No. of messages: {2}",
                productItem.Title, productItem.ISBN, productItem.PageCount);
        }

        private static async Task FindRepliesInLast15Days(IDynamoDBContext context,
            string forumName,
            string threadSubject)
        {
            var replyId = forumName + "#" + threadSubject;
            var twoWeeksAgoDate = DateTime.UtcNow - TimeSpan.FromDays(15);
            var latestReplies = await context.QueryAsync<Reply>(replyId, QueryOperator.GreaterThan, L(twoWeeksAgoDate)).GetRemainingAsync();

            WriteLine("\nFindRepliesInLast15Days: Printing result.....");

            foreach (var r in latestReplies)
            {
                WriteLine("{0}\t{1}\t{2}\t{3}", r.Id, r.PostedBy, r.Message, r.ReplyDateTime);
            }
        }

        private static async Task FindRepliesPostedWithinTimePeriod(IDynamoDBContext context,
            string forumName,
            string threadSubject)
        {
            var forumId = forumName + "#" + threadSubject;
            WriteLine("\nFindRepliesPostedWithinTimePeriod: Printing result.....");

            var startDate = DateTime.UtcNow - TimeSpan.FromDays(30);
            var endDate = DateTime.UtcNow - TimeSpan.FromDays(1);

            IEnumerable<Reply> repliesInAPeriod = await context
                .QueryAsync<Reply>(forumId, QueryOperator.Between, L(startDate, endDate))
                .GetRemainingAsync();

            foreach (var r in repliesInAPeriod)
            {
                WriteLine("{0}\t{1}\t{2}\t{3}", r.Id, r.PostedBy, r.Message, r.ReplyDateTime);
            }
        }

        private static async Task FindProductsPricedLessThanZero(IDynamoDBContext context)
        {
            const int price = 0;
            var products = await context.ScanAsync<Product>(new[]
                {
                    new ScanCondition("Price", ScanOperator.LessThan, price),
                    new ScanCondition("ProductCategory", ScanOperator.Equal, "Book")
                }
            ).GetRemainingAsync();


            WriteLine("\nFindProductsPricedLessThanZero: Printing result.....");

            foreach (var p in products)
            {
                WriteLine($"{p.Id}\t{p.Title}\t{p.Price}\t{p.ISBN}");
            }
        }
    }

    [DynamoDBTable("Reply")]
    public class Reply
    {
        [DynamoDBHashKey] //Partition key
        public string Id { get; set; }

        [DynamoDBRangeKey] //Sort key
        public DateTime ReplyDateTime { get; set; }

        // Properties included implicitly.
        public string Message { get; set; }

        // Explicit property mapping with object persistence model attributes.
        [DynamoDBProperty("LastPostedBy")] public string PostedBy { get; set; }

        // Property to store version number for optimistic locking.
        [DynamoDBVersion] public int? Version { get; set; }
    }

    [DynamoDBTable("Thread")]
    public class Thread
    {
        // PK mapping.
        [DynamoDBHashKey] //Partition key
        public string ForumName { get; set; }

        [DynamoDBRangeKey] //Sort key
        public DateTime Subject { get; set; }

        // Implicit mapping.
        public string Message { get; set; }
        public string LastPostedBy { get; set; }
        public int Views { get; set; }
        public int Replies { get; set; }
        public bool Answered { get; set; }

        public DateTime LastPostedDateTime { get; set; }

        // Explicit mapping (property and table attribute names are different.
        [DynamoDBProperty("Tags")] public List<string> KeywordTags { get; set; }

        // Property to store version number for optimistic locking.
        [DynamoDBVersion] public int? Version { get; set; }
    }

    [DynamoDBTable("Forum")]
    public class Forum
    {
        [DynamoDBHashKey] public string Name { get; set; }

        // All the following properties are explicitly mapped,
        // only to show how to provide mapping.
        [DynamoDBProperty] public int Threads { get; set; }
        [DynamoDBProperty] public int Views { get; set; }
        [DynamoDBProperty] public string LastPostBy { get; set; }
        [DynamoDBProperty] public DateTime LastPostDateTime { get; set; }
        [DynamoDBProperty] public int Messages { get; set; }
    }

    [DynamoDBTable("ProductCatalog")]
    public class Product
    {
        [DynamoDBHashKey] //Partition key
        public int Id { get; set; }

        public string Title { get; set; }
        public string ISBN { get; set; }
        public int Price { get; set; }
        public string PageCount { get; set; }
        public string ProductCategory { get; set; }
        public bool InPublication { get; set; }
    }
}