init

runner/runner.go

@@ -0,0 +1,80 @@
+// Package runner orchestrates the once-a-day simulation against the store.
+package runner
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"time"
+
+	"wh/config"
+	"wh/sim"
+	"wh/store"
+)
+
+const (
+	MetaConfig = "config"
+	MetaDay    = "day"
+	MetaMarket = "market"
+)
+
+// RunNextDay simulates the next day atomically: everything is committed
+// together or not at all, so a crashed run can simply be repeated.
+func RunNextDay(ctx context.Context, s *store.Store, cfg config.Config) (sim.DayResult, error) {
+	var res sim.DayResult
+	cfgJSON, err := json.Marshal(cfg)
+	if err != nil {
+		return res, err
+	}
+	err = s.WithTx(ctx, func(q *store.Q) error {
+		if err := q.LockWorld(ctx); err != nil {
+			return err
+		}
+		// Refuse to continue a world with different parameters.
+		if prev, ok, err := q.GetMeta(ctx, MetaConfig); err != nil {
+			return err
+		} else if ok && prev != string(cfgJSON) {
+			return fmt.Errorf("config differs from the one this world was created with:\n  stored:  %s\n  current: %s", prev, cfgJSON)
+		}
+
+		st, err := q.LoadState(ctx)
+		if err != nil {
+			return err
+		}
+		if st == nil {
+			st = sim.NewState(cfg)
+			if err := q.SetMeta(ctx, MetaConfig, string(cfgJSON)); err != nil {
+				return err
+			}
+			if err := q.SaveState(ctx, st); err != nil { // day 0 snapshot
+				return err
+			}
+		}
+
+		var in sim.DayInput
+		if in.Launches, err = q.PendingLaunches(ctx); err != nil {
+			return err
+		}
+		if in.Uplinks, err = q.PendingUplinks(ctx); err != nil {
+			return err
+		}
+		if res, err = st.RunDay(cfg, in); err != nil {
+			return err
+		}
+		if err := q.SaveState(ctx, st); err != nil {
+			return err
+		}
+		if err := q.RecordRun(ctx, res, time.Now().UTC().Format(time.RFC3339)); err != nil {
+			return err
+		}
+		if err := q.AfterRun(ctx, st); err != nil {
+			return err
+		}
+		mk, _ := json.Marshal(st.Market.Prices)
+		if err := q.SetMeta(ctx, MetaMarket, string(mk)); err != nil {
+			return err
+		}
+		return q.SetMeta(ctx, MetaDay, fmt.Sprint(st.Day))
+	})
+	return res, err
+}