using Microsoft.EntityFrameworkCore;
using Solicitors.Core;
using Solicitors.Core.Data;
using Solicitors.Core.Models;
using Solicitors.Core.Models.Imports;
using Solicitors.Data.RepositorySetup;

namespace Solicitors.Data;

internal class SolicitorsRepository : DbContext, ISolicitorRepository, IReadOnlyCitiesRepository, IRatingsProviderRepository
{
    private readonly IRepoSetupService _setup;
    
    public SolicitorsRepository(IRepoSetupService setup)
    {
        _setup = setup;
    }

    public DbSet<Solicitor> Solicitors { get; set; }
    public DbSet<SolicitorRating> SolicitorRatings { get; set; }
    public DbSet<SolicitorLocation> SolicitorLocations { get; set; }
    public DbSet<SolicitorLocationRating> SolicitorLocationRatings { get; set; }
    public DbSet<City> Cities { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        => _setup.OnConfiguring(optionsBuilder);

    public IAsyncEnumerable<Solicitor> GetAllSolicitorsAsync()
        => Solicitors
            .Include(solicitor => solicitor.Cities)
            .Include(solicitor => solicitor.Locations)
            .ThenInclude(location => location.LocationRatings)
            .Include(solicitor => solicitor.Ratings)
            .AsAsyncEnumerable();

    public Task<Solicitor?> GetSolicitorByIdAsync(Guid id, CancellationToken cancellationToken = default)
        => Solicitors
            .Include(solicitor => solicitor.Cities)
            .Include(solicitor => solicitor.Locations)
            .ThenInclude(location => location.LocationRatings)
            .Include(solicitor => solicitor.Ratings)
            .FirstOrDefaultAsync(x => x.SolicitorId == id, cancellationToken);

    public async Task AddOrUpdateSolicitorAsync(SolicitorData solicitor, CancellationToken cancellationToken)
    {
        var matchingSolicitor = await Solicitors
            .FirstOrDefaultAsync(
                item => item.Name == solicitor.Name, 
                cancellationToken: cancellationToken);

        if (matchingSolicitor is null)
            await AddNewSolicitor(solicitor, cancellationToken);
        else
            await UpdateExistingSolicitor(solicitor, matchingSolicitor, cancellationToken);
    }

    private async Task AddNewSolicitor(
        SolicitorData solicitor, 
        CancellationToken cancellationToken)
    {
        var newSol = new Solicitor()
        {
            Name = solicitor.Name,
            RelativeUrl = solicitor.UrlPath,
            Phone = solicitor.Phone,
            Email = solicitor.Email,
            Website =  solicitor.Website,
            ShortDescription = solicitor.ShortDescription
        };
        Solicitors.Add(newSol);

        var cityTasks = solicitor.Cities
            .Distinct()
            .Select(async (city) =>
            {
                var matchingCity = await Cities.FirstOrDefaultAsync(
                    item => item.Name == city,
                    cancellationToken: cancellationToken);
                
                if (matchingCity is null)
                {
                    matchingCity = new City() { Name = city };
                    Cities.Add(matchingCity);
                    newSol.Cities.Add(matchingCity);
                }

                matchingCity.Solicitors.Add(newSol);
            });
        await Task.WhenAll(cityTasks);

        foreach (var rating in solicitor.Ratings)
        {
            var newRating = new SolicitorRating()
            {
                Value = rating.Value,
                Maximum = rating.MaxValue,
                Provider = rating.RatingProvider,
                Solicitor = newSol
            };
            SolicitorRatings.Add(newRating);
            newSol.Ratings.Add(newRating);
        }

        foreach (var location in solicitor.Offices)
        {
            var newLocation = new SolicitorLocation()
            {
                Address = location.Address,
                Phone = location.Phone,
                Solicitor = newSol
            };
            SolicitorLocations.Add(newLocation);
            newSol.Locations.Add(newLocation);

            foreach (var rating in location.LocationRatings)
            {
                var newLocRating = new SolicitorLocationRating()
                {
                    Value = rating.value,
                    Maximum = rating.MaxValue,
                    Provider = rating.RatingProvider,
                    SolicitorLocation = newLocation
                };
                SolicitorLocationRatings.Add(newLocRating);
                newLocation.LocationRatings.Add(newLocRating);
            }
        }
        
        await SaveChangesAsync(cancellationToken);
    }

    private Task UpdateExistingSolicitor(
        SolicitorData solicitor,
        Solicitor matchingSolicitor,
        CancellationToken cancellationToken)
    {
        // TODO
        return Task.CompletedTask;
    }

    public IAsyncEnumerable<string> GetCitiesAsync(CancellationToken cancellationToken)
    {
        return Cities
            .Select(city => city.Name)
            .AsAsyncEnumerable();
    }

    public IAsyncEnumerable<string> GetAllRatingsProvidersAsync()
    {
        return SolicitorRatings
            .Select(rating => rating.Provider)
            .Distinct()
            .OrderBy(x => x == "Solicitors.com" ? 0 : 1)
            .ThenBy(x => x)
            .AsAsyncEnumerable();
    }
}