package fetcher

import (
	"context"
	"errors"
	"fmt"
	"log/slog"
	"sync"
	"time"

	"git.avsdev.uk/Go/job-search/internal/config"
	"git.avsdev.uk/Go/job-search/internal/util"
)

var ErrNoNewReleases = fmt.Errorf("%w: no new releases", util.ErrWorkerNoWork)

// Run starts a worker for each enabled source and blocks until every worker
// has stopped. Workers stop when ctx is cancelled, or when any worker stops
// with an error, which starts a shutdown of all of them. The errors are
// logged as they happen and returned joined; nil means a clean shutdown.
func Run(
	ctx context.Context, conf *config.JobSearchConfig, since time.Time,
) error {
	ctx, cancel := context.WithCancel(ctx)
	defer cancel()

	var (
		wg   sync.WaitGroup
		mu   sync.Mutex
		errs []error
	)

	start := func(
		name string,
		run func(context.Context, *config.JobSearchConfig, time.Time) error,
	) {
		wg.Add(1)
		go func() {
			defer wg.Done()
			if err := run(ctx, conf, since); err != nil {
				slog.Error("source stopped, shutting down", "source", name, "err", err)
				mu.Lock()
				errs = append(errs, fmt.Errorf("%s: %w", name, err))
				mu.Unlock()
				cancel()
			}
		}()
	}

	if conf.Sources.FindATender.Enabled {
		start("FindATender", runFindAOpportunity)
	}
	if conf.Sources.FTSMock.Enabled {
		start("FTSMock", runFTSMock)
	}
	if conf.Sources.Sleeper.Enabled {
		start("Sleeper", runSleeper)
	}

	wg.Wait()
	return errors.Join(errs...)
}