using JobTrackerApi.Data;
using JobTrackerApi.Models;

namespace JobTrackerApi.Services;

public sealed record SavedJobSearchRunResult(
    IReadOnlyList<SavedJobSearchJobResult> Jobs,
    int NewCount,
    bool WasInitialRun);

public sealed record SavedJobSearchJobResult(DiscoveredJob Job, bool IsNew, bool IsDismissed);

public sealed class SavedJobSearchRunner(
    JobTrackerContext db,
    IJobDiscoverySearchService discovery,
    TimeProvider timeProvider)
{
    public async Task<SavedJobSearchRunResult> RunAsync(SavedJobSearch search, CancellationToken cancellationToken)
    {
        var jobs = await discovery.SearchAsync(search.Query, search.Location, cancellationToken);
        var now = timeProvider.GetUtcNow();
        var wasInitialRun = search.LastRunAtUtc is null;
        var existing = search.Results.ToDictionary(item => item.ExternalJobId, StringComparer.OrdinalIgnoreCase);
        var results = new List<SavedJobSearchJobResult>(jobs.Count);
        var newCount = 0;
        foreach (var job in jobs)
        {
            var isNew = !existing.TryGetValue(job.Id, out var state);
            if (state is null)
            {
                state = new SavedJobSearchResult { ExternalJobId = job.Id, FirstSeenAtUtc = now, LastSeenAtUtc = now };
                search.Results.Add(state);
                db.SavedJobSearchResults.Add(state);
                newCount++;
            }
            else state.LastSeenAtUtc = now;
            results.Add(new SavedJobSearchJobResult(job, isNew, state.IsDismissed));
        }

        search.LastRunAtUtc = now;
        search.UpdatedAtUtc = now;
        return new SavedJobSearchRunResult(results, newCount, wasInitialRun);
    }
}