using System.IO;
using System.Linq;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.DataProtection;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using nuget_host.Data;
using nuget_host.Entities;

namespace nuget_host.Controllers
{

    [AllowAnonymous]
    public partial class PackagesController : Controller
    {
        private readonly ILogger<PackagesController> logger;
        private readonly IDataProtector protector;

        private readonly NugetSettings nugetSettings;
        ApplicationDbContext dbContext;

        public PackagesController(
            ILoggerFactory loggerFactory,
            IDataProtectionProvider provider,
            IOptions<NugetSettings> nugetOptions,
            ApplicationDbContext dbContext)
        {
            logger = loggerFactory.CreateLogger<PackagesController>();
            nugetSettings = nugetOptions.Value;
            protector = provider.CreateProtector(nugetSettings.ProtectionTitle);
            this.dbContext = dbContext;
        }

        const string defaultSemVer = "2.0.0";
        // dotnet add . package -s http://localhost:5000/packages nuget-cli
        // packages/FindPackagesById()?id='nuget-cli'&semVerLevel=2.0.0

        // Search
        // GET {@id}?q={QUERY}&skip={SKIP}&take={TAKE}&prerelease={PRERELEASE}&semVerLevel={SEMVERLEVEL}&packageType={PACKAGETYPE}

        [HttpGet("~/search/index.json")]
        public IActionResult Index(
            string q,
            string semVerLevel = defaultSemVer,
            bool prerelease = false,
            string packageType = null,
            int skip = 0,
            int take = 25)
        {
            if (string.IsNullOrEmpty(q))
            {
                ModelState.AddModelError("q", "no value");
                return NotFound(ModelState);
            }
            else
            {
                var scope = dbContext.Packages
                .Include(p => p.Versions)
                .Where(
                    p => (CamelCaseMatch(p.Id, q) || SeparatedByMinusMatch(p.Id, q))
                    && (prerelease || p.Versions.Any(v => !v.IsPrerelease))
                    && (packageType == null || p.Versions.Any(v => v.Type == packageType))
                );
                var result = new
                {
                    totalHits = scope.Count(),
                    data = scope.Skip(skip).Take(take).ToArray()
                };
                return Ok(result);
            }
        }

        protected static bool CamelCaseMatch(string id, string q)
        {
            // Assert.False (q==null);
            string query = q;
            if (query.Length == 0) return false;

            while (id.Length > 0)
            {
                int i = 0;
                while (id.Length > i && char.IsLower(id[i])) i++;
                if (i == 0) break;
                id = id.Substring(i);
                if (id.StartsWith(q, System.StringComparison.OrdinalIgnoreCase)) return true;
            }
            return false;
        }
        protected static bool SeparatedByMinusMatch(string id, string q)
        {
            foreach (var part in id.Split('-'))
            {
                if (part.StartsWith(q, System.StringComparison.OrdinalIgnoreCase)) return true;
            }
            return false;
        }
        // GET /autocomplete?id=nuget.protocol&prerelease=true
        [HttpGet("~/autocomplete")]
        public IActionResult AutoComplete(
            string id,
            string semVerLevel = defaultSemVer,
            bool prerelease = false,
            string packageType = null,
            int skip = 0,
            int take = 25)
        {
            return Ok(new
            {
                data =
                     dbContext.PackageVersions.Where(
                         v => v.PackageId == id
                            && (prerelease || !v.IsPrerelease)
                            && (packageType == null || v.Type == packageType)
                     ).Select(v => v.FullString)
                     .Skip(skip).Take(take).ToArray()
            });
        }


    }
}