using System.Security.Claims;
using System.Text.Json;
using Elements.Data;
using Elements.Data.Models;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using SixLabors.ImageSharp;
using SixLabors.ImageSharp.Formats.Png;
using SixLabors.ImageSharp.PixelFormats;

namespace Elements.Backend.Controllers;

[ApiController]
public class SuggestionController : ControllerBase
{
    private readonly ApplicationDbContext _dbContext;

    public SuggestionController(ApplicationDbContext dbContext)
    {
        _dbContext = dbContext;
    }

    [Route("/suggestion/search")]
    [HttpGet]
    public async Task<IActionResult> GetSuggestions(int firstElementId, int secondElementId)
    {
        bool firstExists = await _dbContext.Elements.AnyAsync(e => e.Id == firstElementId);
        bool secondExists = await _dbContext.Elements.AnyAsync(e => e.Id == secondElementId);
        if (!firstExists || !secondExists)
            return BadRequest();
        
        IEnumerable<Suggestion> suggestion = await _dbContext.Suggestions
            .Where(s =>
                (s.FirstElementId == firstElementId && s.SecondElementId == secondElementId) ||
                (s.FirstElementId == secondElementId && s.SecondElementId == firstElementId))
            .Include(suggestion => suggestion.Votes)
            .ToListAsync();
        if (!suggestion.Any())
            return NotFound();

        var result = suggestion.Select(s => new
        {
            s.Id,
            s.Name,
            Icon = Convert.ToBase64String(s.Icon),
            s.FirstElementId,
            s.SecondElementId,
            Votes = s.Votes.Count,
            s.UserId,
            s.VotingEnd
        }).ToList();
        
        var serializeOptions = new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase };
        return Ok(JsonSerializer.Serialize(result, serializeOptions));
    }

    public class SuggestionVoteModel
    {
        public required int Id { get; set; }
    }

    [Route("/suggestion/vote")]
    [Authorize]
    [HttpPost]
    public async Task<IActionResult> PostVote([FromBody] SuggestionVoteModel vote)
    {
        Suggestion? suggestion = await _dbContext.Suggestions
            .Include(s => s.Votes)
            .FirstOrDefaultAsync(s => s.Id == vote.Id);
        if (suggestion == null)
            return NotFound();
        
        IEnumerable<Claim> claims = User.Claims;
        string? currentUserId = claims.FirstOrDefault(claim => claim.Type == "id")?.Value;
        if (currentUserId == null)
            return StatusCode(StatusCodes.Status500InternalServerError);
        //Check if user is voting for own element
        if (suggestion.UserId.ToString() == currentUserId)
            return BadRequest();
        //Check if user already voted for this element
        IEnumerable<Vote> suggestionVotes = suggestion.Votes;
        if (suggestionVotes.Any(s => s.UserId.ToString() == currentUserId))
            return BadRequest();

        Vote newVote = new()
        {
            UserId = int.Parse(currentUserId),
            SuggestionId = suggestion.Id
        };
        await _dbContext.Votes.AddAsync(newVote);
        await _dbContext.SaveChangesAsync();

        return Ok();
    }

    public class SuggestionCreateModel
    {
        public required string Name { get; set; }
        public required string IconBitmap { get; set; }
        public required int FirstElementId { get; set; }
        public required int SecondElementId { get; set; }
    }

    [Route("/suggestion/create")]
    [Authorize]
    [HttpPost]
    public async Task<IActionResult> PostSuggestion([FromBody] SuggestionCreateModel suggestion)
    {
        IEnumerable<Claim> claims = User.Claims;
        string? currentUserId = claims.FirstOrDefault(claim => claim.Type == "id")?.Value;
        if (currentUserId == null)
            return StatusCode(StatusCodes.Status500InternalServerError);

        //User already suggested something
        if (await _dbContext.Suggestions.AnyAsync(s => s.UserId.ToString() == currentUserId))
            return BadRequest();

        Suggestion newSuggestion = new()
        {
            CreationDate = DateTime.UtcNow,
            Name = suggestion.Name,
            Icon = ConvertBitmapToPng(Convert.FromBase64String(suggestion.IconBitmap)),
            FirstElementId = suggestion.FirstElementId,
            SecondElementId = suggestion.SecondElementId,
            VotingEnd = DateTime.UtcNow + TimeSpan.FromSeconds(10),
            UserId = int.Parse(currentUserId)
        };
        await _dbContext.Suggestions.AddAsync(newSuggestion);
        await _dbContext.SaveChangesAsync();

        Vote newVote = new()
        {
            UserId = int.Parse(currentUserId),
            SuggestionId = newSuggestion.Id
        };
        await _dbContext.Votes.AddAsync(newVote);
        await _dbContext.SaveChangesAsync();
        
        return Ok();
    }
    
    private static byte[] ConvertBitmapToPng(byte[] bitmapData)
    {
        Image<Argb32> image = Image.LoadPixelData<Argb32>(bitmapData, 16, 16);
        using MemoryStream resultStream = new();
        image.Save(resultStream, new PngEncoder());
        return resultStream.ToArray();
    }
}