using System.Text.Encodings.Web;
using System.Text.Unicode;
using JobsMedical.Web.Data;
using JobsMedical.Web.Models;
using JobsMedical.Web.Services;
using Microsoft.AspNetCore.Authentication.Cookies;
using Microsoft.AspNetCore.HttpOverrides;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddRazorPages();

// Interest tracking + recommendation engine.
builder.Services.AddHttpContextAccessor();
builder.Services.AddMemoryCache();
builder.Services.AddScoped<VisitorContext>();
builder.Services.AddScoped<InterestService>();
builder.Services.AddScoped<RecommendationService>();
builder.Services.AddHttpClient("sms");
builder.Services.AddSingleton<ISmsSender, KavenegarSmsSender>();
builder.Services.AddScoped<OtpService>();
builder.Services.AddSingleton<CaptchaService>();
builder.Services.AddScoped<SubmissionGuard>();
builder.Services.AddScoped<NotificationService>();
builder.Services.AddScoped<PushNotifier>();
builder.Services.AddSingleton<NotificationHub>();   // in-memory SSE broker (live in-app notifications)
// Listing parser: heuristic now; swap for an LLM-backed IListingParser later.
builder.Services.AddSingleton<IListingParser, HeuristicListingParser>();

// Scrape/ingestion engine: pluggable sources → dedupe → parse → validate → (AI audit) → publish/queue.
builder.Services.AddHttpClient("scrape", c =>
{
    c.Timeout = TimeSpan.FromSeconds(20);
    c.DefaultRequestHeaders.UserAgent.ParseAdd("Mozilla/5.0 (compatible; HamkadrBot/1.0)");
});
builder.Services.AddHttpClient("ai");
builder.Services.AddSingleton<JobsMedical.Web.Services.Scraping.ListingValidator>();
builder.Services.AddSingleton<JobsMedical.Web.Services.Scraping.IAiAuditor,
    JobsMedical.Web.Services.Scraping.OpenAiCompatibleAuditor>();
builder.Services.AddScoped<JobsMedical.Web.Services.Scraping.SettingsService>();
builder.Services.AddSingleton<JobsMedical.Web.Services.Scraping.IListingSource,
    JobsMedical.Web.Services.Scraping.SampleListingSource>();
builder.Services.AddSingleton<JobsMedical.Web.Services.Scraping.IListingSource,
    JobsMedical.Web.Services.Scraping.TelegramListingSource>();
builder.Services.AddSingleton<JobsMedical.Web.Services.Scraping.IListingSource,
    JobsMedical.Web.Services.Scraping.BaleListingSource>();
builder.Services.AddSingleton<JobsMedical.Web.Services.Scraping.IListingSource,
    JobsMedical.Web.Services.Scraping.DivarListingSource>();
builder.Services.AddSingleton<JobsMedical.Web.Services.Scraping.IListingSource,
    JobsMedical.Web.Services.Scraping.MedjobsListingSource>();
builder.Services.AddSingleton<JobsMedical.Web.Services.Scraping.IListingSource,
    JobsMedical.Web.Services.Scraping.WebsiteListingSource>();
builder.Services.AddScoped<JobsMedical.Web.Services.Scraping.ListingArchiver>();
builder.Services.AddScoped<JobsMedical.Web.Services.Scraping.IngestionService>();
builder.Services.AddHostedService<JobsMedical.Web.Services.Scraping.IngestionWorker>();

// Phone-OTP cookie auth.
builder.Services.AddAuthentication(CookieAuthenticationDefaults.AuthenticationScheme)
    .AddCookie(o =>
    {
        o.LoginPath = "/Account/Login";
        o.AccessDeniedPath = "/Account/Login";
        o.ExpireTimeSpan = TimeSpan.FromDays(30);
        o.SlidingExpiration = true;
    });

// Emit Persian/Arabic characters directly in HTML instead of \u-style entities.
builder.Services.AddSingleton(HtmlEncoder.Create(
    UnicodeRanges.BasicLatin, UnicodeRanges.Arabic, UnicodeRanges.ArabicSupplement,
    UnicodeRanges.ArabicExtendedA, UnicodeRanges.GeneralPunctuation));

builder.Services.AddDbContext<AppDbContext>(opt =>
    opt.UseNpgsql(builder.Configuration.GetConnectionString("Default")));

var app = builder.Build();

// Apply migrations + seed on startup (fine for MVP single-instance deploy).
using (var scope = app.Services.CreateScope())
{
    var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
    db.Database.Migrate();
    await SeedData.SeedReferenceAsync(db);   // cities/roles/districts always
    // Demo board in Development, or whenever the admin has turned Demo Mode on.
    var st = await scope.ServiceProvider
        .GetRequiredService<JobsMedical.Web.Services.Scraping.SettingsService>().GetAsync();
    if (app.Environment.IsDevelopment() || st.DemoMode) await SeedData.SeedDemoAsync(db);
    // Archive any listings that went stale while the app was down.
    await scope.ServiceProvider
        .GetRequiredService<JobsMedical.Web.Services.Scraping.ListingArchiver>()
        .ArchiveStaleAsync();
}

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Error");
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}

// Behind nginx (TLS terminated upstream): trust X-Forwarded-Proto/For so the app knows it's
// HTTPS — required for correct secure cookies and to avoid HTTPS-redirect loops.
var forwardedOptions = new ForwardedHeadersOptions
{
    ForwardedHeaders = ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto
};
forwardedOptions.KnownIPNetworks.Clear();   // only nginx can reach the container's bound port
forwardedOptions.KnownProxies.Clear();
app.UseForwardedHeaders(forwardedOptions);

app.UseHttpsRedirection();

app.UseRouting();

// Assign every visitor a stable cookie id so we can track interest from the first visit.
app.UseMiddleware<VisitorCookieMiddleware>();

app.UseAuthentication();
app.UseAuthorization();

app.MapStaticAssets();
app.MapRazorPages()
   .WithStaticAssets();

// Lightweight liveness probe for the deploy health-wait loop (and uptime checks).
app.MapGet("/healthz", () => Results.Text("ok"));

// ---- PWA: web manifest + service worker (served from root for full scope) ----
app.MapGet("/manifest.webmanifest", () => Results.Content("""
{
  "name": "همکادر — شیفت و استخدام کادر درمان",
  "short_name": "همکادر",
  "lang": "fa", "dir": "rtl",
  "start_url": "/", "scope": "/",
  "display": "standalone", "orientation": "portrait",
  "background_color": "#f4f7f9", "theme_color": "#0e8f8a",
  "icons": [
    { "src": "/icons/icon-192.png", "sizes": "192x192", "type": "image/png", "purpose": "any maskable" },
    { "src": "/icons/icon-512.png", "sizes": "512x512", "type": "image/png", "purpose": "any maskable" }
  ],
  "shortcuts": [
    { "name": "شیفت‌ها", "url": "/Shifts" },
    { "name": "استخدام", "url": "/Jobs" }
  ]
}
""", "application/manifest+json"));

// Store a browser's push subscription (from the "enable notifications" flow).
app.MapPost("/push/subscribe", async (PushSubscriptionDto dto, AppDbContext db, VisitorContext vc) =>
{
    if (string.IsNullOrWhiteSpace(dto.Endpoint) || dto.Keys?.P256dh is null || dto.Keys?.Auth is null)
        return Results.BadRequest();
    if (!await db.WebPushSubscriptions.AnyAsync(s => s.Endpoint == dto.Endpoint))
    {
        db.WebPushSubscriptions.Add(new WebPushSubscription
        {
            Endpoint = dto.Endpoint, P256dh = dto.Keys.P256dh, Auth = dto.Keys.Auth, VisitorId = vc.VisitorId,
        });
        await db.SaveChangesAsync();
    }
    return Results.Ok();
});

// Live notification stream (Server-Sent Events). Runs over our own origin, so it reaches
// users in Iran (unlike Web Push, which goes via the browser's blocked push service).
// The browser keeps this open while the tab/PWA is alive; the client updates the bell,
// shows a toast, and fires a local OS notification (no push server) when permission is on.
app.MapGet("/notifications/stream", async (HttpContext ctx, NotificationHub hub) =>
{
    var claim = ctx.User.FindFirst(System.Security.Claims.ClaimTypes.NameIdentifier)?.Value;
    if (!int.TryParse(claim, out var uid)) { ctx.Response.StatusCode = 401; return; }

    ctx.Response.Headers.ContentType = "text/event-stream";
    ctx.Response.Headers.CacheControl = "no-cache";
    ctx.Response.Headers.Connection = "keep-alive";
    ctx.Response.Headers["X-Accel-Buffering"] = "no";   // tell nginx not to buffer the stream
    ctx.Features.Get<Microsoft.AspNetCore.Http.Features.IHttpResponseBodyFeature>()?.DisableBuffering();

    var (reader, unsubscribe) = hub.Subscribe(uid);
    var ct = ctx.RequestAborted;
    try
    {
        await ctx.Response.WriteAsync(": connected\n\n", ct);
        await ctx.Response.Body.FlushAsync(ct);
        while (!ct.IsCancellationRequested)
        {
            var readTask = reader.WaitToReadAsync(ct).AsTask();
            var keepAlive = Task.Delay(TimeSpan.FromSeconds(25), ct);
            if (await Task.WhenAny(readTask, keepAlive) == keepAlive)
            {
                await ctx.Response.WriteAsync(": ping\n\n", ct);   // comment line keeps the connection warm
                await ctx.Response.Body.FlushAsync(ct);
                continue;
            }
            if (!await readTask) break;
            while (reader.TryRead(out var notice))
            {
                var json = System.Text.Json.JsonSerializer.Serialize(notice);
                await ctx.Response.WriteAsync($"event: notice\ndata: {json}\n\n", ct);
                await ctx.Response.Body.FlushAsync(ct);
            }
        }
    }
    catch (OperationCanceledException) { /* client disconnected — normal */ }
    finally { unsubscribe(); }
}).RequireAuthorization();

// User-submitted report against a listing (abuse/fake/wrong info).
app.MapPost("/report", async (HttpContext ctx, AppDbContext db, VisitorContext vc,
    [FromForm] string targetType, [FromForm] int targetId, [FromForm] string reason,
    [FromForm] string? label, [FromForm] string? returnUrl) =>
{
    if (!string.IsNullOrWhiteSpace(reason) && Enum.TryParse<ReportTargetType>(targetType, true, out var tt))
    {
        int? uid = ctx.User?.FindFirst(System.Security.Claims.ClaimTypes.NameIdentifier) is { } c
            && int.TryParse(c.Value, out var n) ? n : null;
        db.Reports.Add(new Report
        {
            TargetType = tt, TargetId = targetId, TargetLabel = label,
            Reason = reason.Trim()[..Math.Min(reason.Trim().Length, 500)],
            ReporterUserId = uid, ReporterVisitorId = vc.VisitorId,
        });
        await db.SaveChangesAsync();
    }
    return Results.Redirect((string.IsNullOrWhiteSpace(returnUrl) ? "/" : returnUrl) + "?reported=1");
}).DisableAntiforgery();

app.MapGet("/sw.js", () => Results.Content("""
const CACHE = 'hamkadr-v1';
self.addEventListener('install', e => { self.skipWaiting(); e.waitUntil(caches.open(CACHE).then(c => c.addAll(['/']))); });
self.addEventListener('activate', e => { e.waitUntil(caches.keys().then(ks => Promise.all(ks.filter(k => k !== CACHE).map(k => caches.delete(k))))); self.clients.claim(); });
self.addEventListener('fetch', e => {
  const req = e.request;
  if (req.method !== 'GET' || new URL(req.url).origin !== location.origin) return;
  e.respondWith(fetch(req).then(res => { const copy = res.clone(); caches.open(CACHE).then(c => c.put(req, copy)); return res; })
    .catch(() => caches.match(req).then(m => m || caches.match('/'))));
});
self.addEventListener('push', e => {
  let d = { title: 'همکادر', body: 'فرصت جدید برای شما', url: '/' };
  try { if (e.data) d = Object.assign(d, e.data.json()); } catch (_) { if (e.data) d.body = e.data.text(); }
  e.waitUntil(self.registration.showNotification(d.title, { body: d.body, icon: '/icons/icon-192.png', badge: '/icons/icon-192.png', dir: 'rtl', lang: 'fa', data: { url: d.url } }));
});
self.addEventListener('notificationclick', e => {
  e.notification.close();
  const url = (e.notification.data && e.notification.data.url) || '/';
  e.waitUntil(clients.matchAll({ type: 'window' }).then(cl => { for (const c of cl) { if ('focus' in c) { c.navigate(url); return c.focus(); } } return clients.openWindow(url); }));
});
""", "text/javascript"));

// ---- SEO: robots.txt + dynamic sitemap.xml (so Google indexes every live shift/job page) ----
app.MapGet("/robots.txt", (HttpContext ctx) =>
{
    var b = $"{ctx.Request.Scheme}://{ctx.Request.Host}";
    return Results.Text($"User-agent: *\nAllow: /\nDisallow: /Admin\nDisallow: /Employer\nSitemap: {b}/sitemap.xml\n", "text/plain");
});

app.MapGet("/sitemap.xml", async (HttpContext ctx, AppDbContext db) =>
{
    var b = $"{ctx.Request.Scheme}://{ctx.Request.Host}";
    var today = DateOnly.FromDateTime(DateTime.UtcNow);
    var jobCutoff = JobsMedical.Web.Services.Scraping.ListingPolicy.JobCutoffUtc;

    var sb = new System.Text.StringBuilder();
    sb.Append("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n");
    sb.Append("<urlset xmlns=\"http://www.sitemaps.org/schemas/sitemap/0.9\">\n");
    void Url(string loc, DateTime? mod = null, string freq = "daily")
    {
        sb.Append("  <url><loc>").Append(System.Security.SecurityElement.Escape(loc)).Append("</loc>");
        if (mod is not null) sb.Append("<lastmod>").Append(mod.Value.ToString("yyyy-MM-dd")).Append("</lastmod>");
        sb.Append("<changefreq>").Append(freq).Append("</changefreq></url>\n");
    }

    foreach (var p in new[] { "", "/Shifts", "/Jobs", "/Calendar", "/Facilities" })
        Url($"{b}{p}", DateTime.UtcNow, p == "" ? "daily" : "hourly");

    foreach (var s in await db.Shifts.Where(s => s.Status == ShiftStatus.Open && s.Date >= today)
                 .Select(s => new { s.Id, s.CreatedAt }).ToListAsync())
        Url($"{b}/Shifts/Details/{s.Id}", s.CreatedAt, "daily");

    foreach (var j in await db.JobOpenings.Where(j => j.Status == ShiftStatus.Open && j.CreatedAt >= jobCutoff)
                 .Select(j => new { j.Id, j.CreatedAt }).ToListAsync())
        Url($"{b}/Jobs/Details/{j.Id}", j.CreatedAt, "weekly");

    sb.Append("</urlset>");
    return Results.Content(sb.ToString(), "application/xml");
});

app.Run();
