using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Net.Http;
using System.Net.Http.Json;
using System.Threading.Tasks;
using contact.Services;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.AspNetCore.Mvc.Rendering;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;

namespace contact.Pages
{
    [BindProperties(SupportsGet = true)]
    public class RequestFormModel
    {
        public RequestFormModel()
        {
            DataCenter = "SF";
        }
        [Required]
        public string Name { get; set; }
        [Required]
        public string Company { get; set; }
        [Required, EmailAddress]
        public string Email { get; set; }
        [Required]
        public string DataCenter { get; set; }
    }

    public class RequestModel : PageModel
    {
        private const string EvaluateUrl = "https://ayanova.com/docs/ay-evaluate/";

        [BindProperty(SupportsGet = true)]
        public RequestFormModel SubRequest { get; set; }

        //Set when neither Sockeye nor the email got the request, so the page can say so
        public bool SendFailed { get; set; }

        public List<SelectListItem> DataCenters { get; } = new List<SelectListItem>
        {
            new SelectListItem { Value = "SF", Text = "San Francisco" },
            new SelectListItem { Value = "ATL", Text = "Atlanta" },
            new SelectListItem { Value = "NY", Text = "New York" },
            new SelectListItem { Value = "TOR", Text = "Toronto" },
            new SelectListItem { Value = "AMS", Text = "Amsterdam" },
            new SelectListItem { Value = "LON", Text = "London" },
            new SelectListItem { Value = "FFT", Text = "Frankfurt" },
            new SelectListItem { Value = "SNG", Text = "Singapore" },
            new SelectListItem { Value = "BNG", Text = "Bangalore" },
            new SelectListItem { Value = "SYD", Text = "Sydney Australia" }
        };

        private readonly IConfiguration _configuration;
        private readonly IHttpClientFactory _httpClientFactory;
        private readonly MailSender _mail;
        private readonly ILogger<RequestModel> _logger;

        public RequestModel(IConfiguration configuration, IHttpClientFactory httpClientFactory, MailSender mail, ILogger<RequestModel> logger)
        {
            _configuration = configuration;
            _httpClientFactory = httpClientFactory;
            _mail = mail;
            _logger = logger;
        }

        public void OnGet()
        {
        }

        public async Task<IActionResult> OnPostAsync()
        {
            //The select can be bypassed by a hand-crafted POST; only accept codes from the list
            if (!DataCenters.Any(d => d.Value == SubRequest.DataCenter))
            {
                ModelState.AddModelError("SubRequest.DataCenter", "Please choose a data center from the list.");
            }

            if (!ModelState.IsValid)
            {
                return Page();
            }

            if (ContactModel.IsBlocked(SubRequest.Company))
            {
                return Redirect(EvaluateUrl);
            }

            //1. Record the request in Sockeye. A failure here is logged and reported in the email,
            //   so the trial can be set up by hand instead of the request disappearing.
            string sockeyeResult;
            bool sockeyeOk;
            try
            {
                await PostRequestToSockeyeAsync();
                sockeyeOk = true;
                sockeyeResult = "Recorded in Sockeye.";
            }
            catch (Exception ex)
            {
                sockeyeOk = false;
                sockeyeResult = $"NOT RECORDED IN SOCKEYE ({ex.Message}). Set this trial up by hand.";
                _logger.LogError(ex, "Trial request post to Sockeye failed. {Body}", Describe());
            }

            //2. Notify support. Email is in the body; From is the form account, so it was never there before either
            var body = $"{Describe()}\r\n\r\nSockeye:\r\n{sockeyeResult}";
            var subject = sockeyeOk
                ? $"Trial request from {SubRequest.Company}"
                : $"Trial request NOT RECORDED from {SubRequest.Company}";
            bool mailOk;
            try
            {
                await _mail.SendToSupportAsync(subject, body, SubRequest.Name, SubRequest.Email);
                mailOk = true;
            }
            catch (Exception ex)
            {
                mailOk = false;
                _logger.LogError(ex, "Trial request email failed. Submission:\r\n{Body}", body);
            }

            //Either path reaching John means the request is not lost; only both failing is a failure for the visitor
            if (!sockeyeOk && !mailOk)
            {
                SendFailed = true;
                return Page();
            }

            return Redirect(EvaluateUrl);
        }

        private string Describe() =>
            $"Name:\r\n{SubRequest.Name}\r\n\r\nCompany:\r\n{SubRequest.Company}\r\n\r\nEmail:\r\n{SubRequest.Email}\r\n\r\nDataCenter:\r\n{SubRequest.DataCenter}";

        private async Task PostRequestToSockeyeAsync()
        {
            //Sockeye:TrialRequestUrl. On the server this is http://127.0.0.1:7575/subscription-server-trial-request,
            //straight to Kestrel on the same host, so it depends on neither DNS nor the droplet reaching its own reserved IP.
            var url = _configuration["Sockeye:TrialRequestUrl"];
            if (string.IsNullOrWhiteSpace(url))
            {
                throw new InvalidOperationException("Sockeye:TrialRequestUrl is not configured");
            }

            var r = new
            {
                dataCenter = SubRequest.DataCenter,
                email = SubRequest.Email,
                company = SubRequest.Company,
                name = SubRequest.Name,
                rValue = "totallylegit"
            };

            var client = _httpClientFactory.CreateClient("sockeye");
            var response = await client.PostAsJsonAsync(url, r);
            //Previously the response was never checked, so a rejected request failed silently
            response.EnsureSuccessStatusCode();
        }
    }
}