feat: add NAV job discovery

2026-07-30 22:57:17 +02:00
parent 7fab996407
commit 405e6d833c
6 changed files with 233 additions and 3 deletions
@@ -0,0 +1,110 @@
+using System.Net.Http.Headers;
+using System.Text.Json;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.Caching.Memory;
+
+namespace JobTrackerApi.Controllers;
+
+[ApiController]
+[Route("api/job-discovery")]
+[Authorize(AuthenticationSchemes = "local")]
+public sealed class JobDiscoveryController : ControllerBase
+{
+    private const string BaseUrl = "https://pam-stilling-feed.nav.no";
+    private readonly IHttpClientFactory _clients;
+    private readonly IConfiguration _configuration;
+    private readonly IMemoryCache _cache;
+
+    public JobDiscoveryController(IHttpClientFactory clients, IConfiguration configuration, IMemoryCache cache)
+    {
+        _clients = clients;
+        _configuration = configuration;
+        _cache = cache;
+    }
+
+    [HttpGet("search")]
+    public async Task<ActionResult<IReadOnlyList<DiscoveredJob>>> Search([FromQuery] string? q, [FromQuery] string? location, CancellationToken cancellationToken)
+    {
+        try
+        {
+            var token = await GetTokenAsync(cancellationToken);
+            var client = _clients.CreateClient();
+            var entries = new Dictionary<string, DiscoveredJob>(StringComparer.OrdinalIgnoreCase);
+            var next = "/api/v1/feed";
+
+            // ponytail: scan the recent event window on demand; add a persisted feed cursor only when
+            // usage makes the bounded request noticeably slow or NAV private-token terms require it.
+            for (var page = 0; page < 20 && !string.IsNullOrWhiteSpace(next); page++)
+            {
+                using var request = new HttpRequestMessage(HttpMethod.Get, BaseUrl + next);
+                request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", token);
+                request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
+                if (page == 0) request.Headers.IfModifiedSince = DateTimeOffset.UtcNow.AddDays(-14);
+
+                using var response = await client.SendAsync(request, cancellationToken);
+                response.EnsureSuccessStatusCode();
+                using var json = JsonDocument.Parse(await response.Content.ReadAsStreamAsync(cancellationToken));
+                next = json.RootElement.TryGetProperty("next_url", out var nextElement) ? nextElement.GetString() ?? "" : "";
+
+                foreach (var item in json.RootElement.GetProperty("items").EnumerateArray())
+                {
+                    var feed = item.GetProperty("_feed_entry");
+                    var id = feed.GetProperty("uuid").GetString();
+                    if (string.IsNullOrWhiteSpace(id)) continue;
+                    var status = feed.TryGetProperty("status", out var statusElement) ? statusElement.GetString() : null;
+                    if (!string.Equals(status, "ACTIVE", StringComparison.OrdinalIgnoreCase))
+                    {
+                        entries.Remove(id);
+                        continue;
+                    }
+
+                    entries[id] = new DiscoveredJob(
+                        id,
+                        feed.TryGetProperty("title", out var title) ? title.GetString() ?? "" : "",
+                        feed.TryGetProperty("businessName", out var company) ? company.GetString() : null,
+                        feed.TryGetProperty("municipal", out var municipal) ? municipal.GetString() : null,
+                        item.TryGetProperty("date_modified", out var modified) && modified.TryGetDateTimeOffset(out var date) ? date : null,
+                        $"https://arbeidsplassen.nav.no/stillinger/stilling/{id}",
+                        "nav",
+                        "NO");
+                }
+            }
+
+            var query = (q ?? "").Trim();
+            var place = (location ?? "").Trim();
+            return Ok(entries.Values
+                .Where(job => Contains(job.Title, query) || Contains(job.Company, query))
+                .Where(job => Contains(job.Location, place))
+                .OrderByDescending(job => job.ModifiedAt)
+                .Take(100)
+                .ToList());
+        }
+        catch (Exception ex) when (ex is HttpRequestException or JsonException or InvalidOperationException)
+        {
+            return Problem("NAV job discovery is temporarily unavailable.", statusCode: StatusCodes.Status502BadGateway);
+        }
+    }
+
+    private async Task<string> GetTokenAsync(CancellationToken cancellationToken)
+    {
+        var configured = _configuration["NavJobs:Token"]?.Trim();
+        if (!string.IsNullOrWhiteSpace(configured)) return configured;
+
+        return await _cache.GetOrCreateAsync("nav-jobs-public-token", async entry =>
+        {
+            entry.AbsoluteExpirationRelativeToNow = TimeSpan.FromMinutes(30);
+            var text = await _clients.CreateClient().GetStringAsync(BaseUrl + "/api/publicToken", cancellationToken);
+            var start = text.IndexOf("eyJ", StringComparison.Ordinal);
+            if (start < 0) throw new InvalidOperationException("NAV public token was not returned.");
+            var token = text[start..].Trim();
+            var end = token.IndexOfAny(['\r', '\n', ' ', '\t']);
+            return end < 0 ? token : token[..end];
+        }) ?? throw new InvalidOperationException("NAV public token was not returned.");
+    }
+
+    private static bool Contains(string? value, string filter) =>
+        filter.Length == 0 || (value?.Contains(filter, StringComparison.OrdinalIgnoreCase) ?? false);
+
+    public sealed record DiscoveredJob(string Id, string Title, string? Company, string? Location, DateTimeOffset? ModifiedAt, string Url, string Source, string CountryCode);
+}