package api

import (
	"context"
	"net/http"
)

// detailFillBatchSize bounds how many activities' details/splits are fetched
// per sync trigger, matching the sequential rate-limited fetch in
// internal/sync.Service.FillPendingDetails.
const detailFillBatchSize = 50

func (s *Server) handleSyncRun(w http.ResponseWriter, r *http.Request) {
	ok := s.backgroundSync(func(ctx context.Context) error {
		if err := s.Sync.IncrementalSync(ctx); err != nil {
			return err
		}
		return s.Sync.FillPendingDetails(ctx, detailFillBatchSize)
	})
	if !ok {
		writeError(w, http.StatusConflict, "a sync is already in progress")
		return
	}
	writeJSON(w, http.StatusAccepted, map[string]string{"status": "started"})
}

func (s *Server) handleSyncBackfill(w http.ResponseWriter, r *http.Request) {
	ok := s.backgroundSync(func(ctx context.Context) error {
		if err := s.Sync.Backfill(ctx); err != nil {
			return err
		}
		return s.Sync.FillPendingDetails(ctx, detailFillBatchSize)
	})
	if !ok {
		writeError(w, http.StatusConflict, "a sync is already in progress")
		return
	}
	writeJSON(w, http.StatusAccepted, map[string]string{"status": "started"})
}

func (s *Server) handleSyncRuns(w http.ResponseWriter, r *http.Request) {
	runs, err := s.DB.ListSyncRuns(r.Context(), 20)
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, runs)
}

func (s *Server) handleSyncStatus(w http.ResponseWriter, r *http.Request) {
	run, ok, err := s.DB.LatestSyncRun(r.Context())
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	remaining, err := s.DB.CountActivitiesMissingDetails(r.Context())
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}

	s.mu.Lock()
	inProgress := s.syncRunning
	s.mu.Unlock()

	progress := s.Sync.Progress()

	resp := map[string]any{
		"in_progress":                inProgress,
		"detail_fill_progress":       progress,
		"activities_pending_details": remaining,
	}
	if ok {
		resp["last_run"] = run
	}
	writeJSON(w, http.StatusOK, resp)
}