feat(api): schedule + runs endpoints; next_run_at on task detail

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

internal/httpapi/tasks.go

@@ -1,9 +1,12 @@
 package httpapi
 
 import (
+	"context"
 	"encoding/json"
 	"net/http"
+	"time"
 
+	"github.com/vasyansk/imap-copier/internal/scheduler"
 	"github.com/vasyansk/imap-copier/internal/store"
 )
 
@@ -50,5 +53,84 @@ func (s *Server) handleGetTask(w http.ResponseWriter, r *http.Request) {
 	for _, a := range accs {
 		views = append(views, accountDTO(a))
 	}
-	writeJSON(w, http.StatusOK, map[string]any{"task": task, "accounts": views})
+	writeJSON(w, http.StatusOK, map[string]any{"task": s.taskViewFor(r.Context(), task), "accounts": views})
+}
+
+// taskView augments the stored task with the server-computed next scheduled run
+// (RFC3339 UTC; null when the schedule is off, the task is running, or broken).
+type taskView struct {
+	store.Task
+	NextRunAt *string `json:"next_run_at"`
+}
+
+func (s *Server) taskViewFor(ctx context.Context, t store.Task) taskView {
+	var nextRunAt *string
+	if t.ScheduleIntervalSeconds > 0 && !t.Broken && t.Status != "running" && t.ScheduleAnchor != nil {
+		last, _ := s.store.LastFinishedRunAt(ctx, t.ID)
+		n := scheduler.NextRun(time.Duration(t.ScheduleIntervalSeconds)*time.Second, *t.ScheduleAnchor, last)
+		str := n.UTC().Format(time.RFC3339)
+		nextRunAt = &str
+	}
+	return taskView{Task: t, NextRunAt: nextRunAt}
+}
+
+// handleSetSchedule enables/changes/disables a task's recurring schedule.
+// Enabling (interval>0) requires every account to pass its connection tests.
+func (s *Server) handleSetSchedule(w http.ResponseWriter, r *http.Request) {
+	taskID, err := pathID(r, "id")
+	if err != nil {
+		http.Error(w, "bad id", http.StatusBadRequest)
+		return
+	}
+	var body struct {
+		IntervalSeconds int64 `json:"interval_seconds"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+		http.Error(w, "bad json", http.StatusBadRequest)
+		return
+	}
+	if body.IntervalSeconds > 0 {
+		accs, err := s.store.ListAccountsByTask(r.Context(), taskID)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+		if !allAccountsTested(accs) {
+			http.Error(w, "all accounts must pass connection tests before scheduling", http.StatusConflict)
+			return
+		}
+	}
+	if err := s.store.SetTaskSchedule(r.Context(), taskID, body.IntervalSeconds); err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	w.WriteHeader(http.StatusNoContent)
+}
+
+// allAccountsTested mirrors the orchestrator's run gate: non-empty and every
+// account OK on both sides.
+func allAccountsTested(accs []store.Account) bool {
+	if len(accs) == 0 {
+		return false
+	}
+	for _, a := range accs {
+		if a.TestSrcStatus != "ok" || a.TestDstStatus != "ok" {
+			return false
+		}
+	}
+	return true
+}
+
+func (s *Server) handleListRuns(w http.ResponseWriter, r *http.Request) {
+	taskID, err := pathID(r, "id")
+	if err != nil {
+		http.Error(w, "bad id", http.StatusBadRequest)
+		return
+	}
+	runs, err := s.store.ListRunsByTask(r.Context(), taskID)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	writeJSON(w, http.StatusOK, runs)
 }