using AX.FireTrainingSys.DTOs;
using AX.FireTrainingSys.Models;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Claims;
using System.Threading.Tasks;

namespace AX.FireTrainingSys.Controllers
{
    /// <summary>
    /// 学习记录控制器。
    /// </summary>
    [Produces("application/json")]
    [Route("api/[controller]")]
    [ApiVersion("1.0")]
    [ApiController]
    public class StudyRecordsController : ControllerBase
    {
        private readonly DriveDbContext dbContext;

        public StudyRecordsController(DriveDbContext dbContext)
        {
            this.dbContext = dbContext;
        }

        /// <summary>
        /// 获得所有学习记录。
        /// </summary>
        /// <param name="options">查询条件</param>
        /// <returns></returns>
        [Authorize(Roles = nameof(RoleType.Admin))]
        [ProducesResponseType(StatusCodes.Status400BadRequest)]
        [ProducesResponseType(StatusCodes.Status401Unauthorized)]
        [ProducesResponseType(StatusCodes.Status403Forbidden)]
        [ProducesResponseType(StatusCodes.Status200OK)]
        [HttpGet]
        public async Task<ActionResult<Page<StudyRecordInfo>>> Get([FromQuery] StudyRecordQueryOptions options)
        {
            var rangeEnd = DateTimeOffset.Now;
            var rangeStart = rangeEnd.AddYears(-1);

            if (string.IsNullOrEmpty(options.Name))
                return BadRequest($"{nameof(options.Name)} can not be empty.");

            if (options.StartTime != default && (options.StartTime < rangeStart || options.StartTime > rangeEnd))
                return BadRequest($"{nameof(options.StartTime)} is out of range.");

            if (options.EndTime != default && (options.EndTime < rangeStart || options.EndTime > rangeEnd))
                return BadRequest($"{nameof(options.EndTime)} is out of range.");

            if (options.EndTime == default)
                options.EndTime = rangeEnd;

            if (options.StartTime == default)
                options.StartTime = options.EndTime.Value.AddMonths(-1);

            if (options.PageNumber == default)
                options.PageNumber = 1;

            if (options.PageSize == default)
                options.PageSize = 100;

            var query = dbContext.StudyRecords
                        .Include(e => e.User)
                        .AsNoTracking();

            query = query.Where(e => e.User.Name == options!.Name);
            query = query.Where(e => e.CreationTime >= options.StartTime!.Value.UtcDateTime);
            query = query.Where(e => e.CreationTime <= options.EndTime!.Value.UtcDateTime);

            if (!string.IsNullOrEmpty(options.PostName))
                query = query.Where(e => e.PostName == options.PostName);

            if (!string.IsNullOrEmpty(options.Catalog))
                query = query.Where(e => e.Catalog == options.Catalog);

            var count = await query.CountAsync();

            query = query.OrderByDescending(e => e.CreationTime);

            if (options.PageNumber > 1)
                query = query.Skip((options.PageNumber.Value - 1) * options.PageSize.Value);

            query = query.Take(options.PageSize.Value);

            var items = await query.Select(e => e.ToDTO())
                                   .ToListAsync();

            var page = new Page<StudyRecordInfo>
            {
                PageNumber = (int)options.PageNumber,
                PageSize = (int)options.PageSize,
                TotalPages = (int)Math.Ceiling((double)count / (int)options.PageSize),
                TotalCount = count,
                Items = items
            };

            return Ok(page);
        }

        /// <summary>
        /// 统计学习记录。
        /// </summary>
        /// <param name="options">查询条件</param>
        /// <returns></returns>
        [Authorize(Roles = nameof(RoleType.Admin))]
        [ProducesResponseType(StatusCodes.Status400BadRequest)]
        [ProducesResponseType(StatusCodes.Status401Unauthorized)]
        [ProducesResponseType(StatusCodes.Status403Forbidden)]
        [ProducesResponseType(StatusCodes.Status200OK)]
        [HttpGet("[action]")]
        public async Task<ActionResult<List<StudyStatisticsInfo>>> Statistics([FromQuery] StudyStatisticsQueryOptions options)
        {
            var rangeEnd = DateTimeOffset.Now;
            var rangeStart = rangeEnd.AddYears(-1);

            if (string.IsNullOrEmpty(options.Name))
                return BadRequest($"{nameof(options.Name)} can not be empty.");

            if (options.StartTime != default && (options.StartTime < rangeStart || options.StartTime > rangeEnd))
                return BadRequest($"{nameof(options.StartTime)} is out of range.");

            if (options.EndTime != default && (options.EndTime < rangeStart || options.EndTime > rangeEnd))
                return BadRequest($"{nameof(options.EndTime)} is out of range.");

            if (options.EndTime == default)
                options.EndTime = rangeEnd;

            if (options.StartTime == default)
                options.StartTime = options.EndTime.Value.AddMonths(-1);

            var query = dbContext.StudyRecords
                        .Include(e => e.User)
                        .AsNoTracking();

            query = query.Where(e => e.User.Name == options!.Name);
            query = query.Where(e => e.CreationTime >= options.StartTime!.Value.UtcDateTime);
            query = query.Where(e => e.CreationTime <= options.EndTime!.Value.UtcDateTime);

            var result = await query.GroupBy(e => new { e.PostName, e.Catalog })
                                    .Select(g => new StudyStatisticsInfo
                                    {
                                        PostName = g.Key.PostName,
                                        Catalog = g.Key.Catalog,
                                        Count = g.Count()
                                    })
                                    .OrderBy(e => e.PostName)
                                    .ThenBy(e => e.Catalog)
                                    .ToListAsync();

            return Ok(result);
        }

        /// <summary>
        /// 创建学习记录。
        /// </summary>
        /// <param name="info">用户信息</param>
        /// <returns></returns>
        [Authorize(Roles = "Profile")]
        [ProducesResponseType(StatusCodes.Status400BadRequest)]
        [ProducesResponseType(StatusCodes.Status401Unauthorized)]
        [ProducesResponseType(StatusCodes.Status403Forbidden)]
        [ProducesResponseType(StatusCodes.Status201Created)]
        [HttpPost]
        public async Task<ActionResult<StudyRecordInfo>> Post([FromBody] StudyRecordInfo info)
        {
            var userid = HttpContext.User.FindFirstValue(JwtClaimTypes.Subject);
            var model = info.ToModel(userid);

            dbContext.StudyRecords.Add(model);

            await dbContext.SaveChangesAsync();

            info.Id = model.Id;
            info.CreationTime = model.CreationTime.ToLocalTime();

            return CreatedAtAction(nameof(Post), info);
        }
    }

    internal static partial class Extensions
    {
        public static StudyRecord ToModel(this StudyRecordInfo info, string userid) => new StudyRecord
        {
            Operation = info.Operation,
            PostName = info.PostName,
            Catalog = info.Catalog,
            Target = info.Target,
            UserId = userid
        };

        public static StudyRecordInfo ToDTO(this StudyRecord model) => new StudyRecordInfo
        {
            Id = model.Id,
            CreationTime = model.CreationTime.ToLocalTime(),
            Operation = model.Operation,
            PostName = model.PostName,
            Catalog = model.Catalog,
            Target = model.Target
        };
    }
}