using Microsoft.EntityFrameworkCore;
using System;
using System.Runtime.Serialization;

namespace ScrumTaskboard
{
    /// <summary>
    /// Provides access to the database via the Entity Framework Core.
    /// </summary>
    /// <remarks>
    /// Each <see cref="DbSet{TEntity}"/> property represents a table.
    /// Tables can be queried and updated via the context class.
    /// </remarks>
    public class TaskContext : DbContext 
    {
        public DbSet<ScrumTask> Tasks { get; set; }
        public DbSet<ScrumUserstory> Userstories { get; set; }
        public DbSet<ScrumCategory> Categories { get; set; }
        public DbSet<ScrumSprint> Sprints { get; set; }
        public DbSet<ScrumStatus> Status { get; set; }
        public DbSet<ScrumProject> Projects { get; set; }
        public DbSet<ScrumUser> Users { get; set; }

        /// <summary>
        /// Creates a new <see cref="TaskContext"/> instance with default options.
        /// </summary>
        public TaskContext() { }
        
        /// <summary>
        /// Creates a new <see cref="TaskContext"/> instance with the given options.
        /// </summary>
        public TaskContext(DbContextOptions<TaskContext> options) : base(options) { }
    }

    /// <summary>
    /// Represents a task in an agile work process.
    /// </summary>
    /// <remarks>
    /// A task is a small piece of work, associated with a larger userstory.
    /// </remarks>
    public class ScrumTask
    {
        public int Id { get; set; }
        public string Title { get; set; }
        public string Content { get; set; }
        
        public int? StatusId { get; set; }
        public ScrumStatus Status { get; set; }

        public int? AssignedToId { get; set; }
        public ScrumUser AssignedTo { get; set; }

        public int? ProjectId { get; set; }
        public ScrumProject Project { get; set; }

        public int? UserstoryId { get; set; }
        public ScrumUserstory Userstory { get; set; }

        public ScrumPrio Priority { get; set; }
    }

    /// <summary>
    /// Represents a userstory in an agile work process.
    /// </summary>
    /// <remarks>
    /// A userstory is a piece of work that can be done in one sprint.
    /// It can be further divided into multiple tasks.
    /// </remarks>
    public class ScrumUserstory
    {
        public int Id { get; set; }
        public string Title { get; set; }
        public string Content { get; set; }
        public ScrumPrio Priority { get; set; }

        public int? StatusId { get; set; }
        public ScrumStatus Status { get; set; }

        public int? CategoryId { get; set; }
        public ScrumCategory Category { get; set; }

        public int? CreatedById { get; set; }
        public ScrumUser CreatedBy { get; set; }

        public int? ProjectId { get; set; }
        public ScrumProject Project { get; set; }

        public int? SprintId { get; set; }
        public ScrumSprint Sprint { get; set; }
    }

    /// <summary>
    /// Represents a category of userstories.
    /// </summary>
    /// <remarks>
    /// Every userstory can optionally be associated with a single category.
    /// This can be helpful to organize work in larger teams.
    /// </remarks>
    public class ScrumCategory
    {
        public int Id { get; set; }
        public string Title { get; set; }
        public string Description { get; set; }
        public string Color { get; set; }

        public int? ProjectId { get; set; }
        public ScrumProject Project { get; set; }
    }

    /// <summary>
    /// Represents an agile sprint.
    /// </summary>
    /// <remarks>
    /// A sprint is typically one to four weeks long. 
    /// Userstories are typically started and completed 
    /// during one sprint.
    /// </remarks>
    public class ScrumSprint
    {
        public int Id { get; set; }
        public string Title { get; set; }
        public string Description { get; set; }
        public DateTime StartDate { get; set; }
        public DateTime EndDate { get; set; }

        public int? ProjectId { get; set; }
        public ScrumProject Project { get; set; }
    }

    /// <summary>
    /// Represents the status of a task or userstory.
    /// </summary>
    /// <remarks>
    /// Classic status are "Backlog", "In Progress" and "Done", but
    /// teams can create others to fit their individual workflow.
    /// </remarks>
    public class ScrumStatus
    {
        public int Id { get; set; }
        public string Title { get; set; }
        public string Description { get; set; }
    }

    /// <summary>
    /// Represents a project that the team works on.
    /// </summary>
    /// <remarks>
    /// Userstories and sprints can be categorized into projects,
    /// to help organization for larger teams.
    /// </remarks>
    public class ScrumProject
    {
        public int Id { get; set; }
        public string Title { get; set; }
        public bool IsPrivate { get; set; }
    }

    /// <summary>
    /// Represents a team member that can work on userstories.
    /// </summary>
    /// <remarks>
    /// This allows teams to track who is working on a userstory
    /// at a given time.
    /// </remarks>
    public class ScrumUser
    {
        public int Id { get; set; }
        public string Name { get; set; }
    }

    public enum ScrumPrio
    {
        [EnumMember(Value = "low")]
        Low,
        [EnumMember(Value = "medium")]
        Medium,
        [EnumMember(Value = "high")]
        High
    }
}