using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.AspNetCore.Http;
using Oqtane.Models;
using Oqtane.Shared;

namespace Oqtane.Repository
{
    public class TenantResolver : ITenantResolver
    {
        private readonly Alias _alias;
        private readonly Tenant _tenant;

        public TenantResolver(IHttpContextAccessor accessor, IAliasRepository aliasRepository, ITenantRepository tenantRepository, SiteState siteState)
        {
            int aliasId = -1;
            string aliasName = "";

            // get alias identifier based on request context
            if (accessor.HttpContext != null)
            {
                // check if an alias is passed as a querystring parameter ( for cross tenant access )
                if (accessor.HttpContext.Request.Query.ContainsKey("aliasid"))
                {
                    aliasId = int.Parse(accessor.HttpContext.Request.Query["aliasid"]);
                }
                else // get the alias from the request url
                {
                    aliasName = accessor.HttpContext.Request.Host.Value;
                    string path = accessor.HttpContext.Request.Path.Value;
                    string[] segments = path.Split(new[] {'/'}, StringSplitOptions.RemoveEmptyEntries);
                    if (segments.Length > 1 && segments[1] == "api" && segments[0] != "~")
                    {
                        aliasName += "/" + segments[0];
                    }

                    if (aliasName.EndsWith("/"))
                    {
                        aliasName = aliasName.Substring(0, aliasName.Length - 1);
                    }
                }
            }
            else // background processes can pass in an alias using the SiteState service
            {
                aliasId = siteState?.Alias?.AliasId ?? -1;
            }

            // get the alias and tenant
            IEnumerable<Alias> aliases = aliasRepository.GetAliases().ToList(); // cached
            if (aliasId != -1)
            {
                _alias = aliases.FirstOrDefault(item => item.AliasId == aliasId);
            }
            else
            {
                
                _alias = aliases.FirstOrDefault(item => item.Name == aliasName
                                                        //if here is only one alias and other methods fail, take it (case of startup install)
                                                        || aliases.Count() == 1);
            }

            if (_alias != null)
            {
                IEnumerable<Tenant> tenants = tenantRepository.GetTenants(); // cached
                _tenant = tenants.FirstOrDefault(item => item.TenantId == _alias.TenantId);
            }
        }

        public Alias GetAlias()
        {
            return _alias;
        }

        public Tenant GetTenant()
        {
            return _tenant;
        }
    }
}