package runtime

import (
	"context"
	"encoding/json"
	"fmt"
	"testing"
	"time"

	"git.5iot.com/iotlcm-public/iotlcm-worker-svr/internal/fullsync/contract"
	"git.5iot.com/iotlcm-public/iotlcm-worker-svr/internal/queue/zset"
	"git.5iot.com/iotlcm-public/iotlcm-worker-svr/internal/testutil"
)

// seedReplaySource writes a completed source run with n failures into store.
func seedReplaySource(t *testing.T, redis zset.RedisClient, store *zset.Store, name string, n int) {
	t.Helper()
	ctx := context.Background()
	key, _ := store.RunMetaKey(name)
	failed, _ := store.FailedKey(name)
	if _, err := redis.Do(ctx, "HSET", key, "runId", name, "operation", "usage", "status", "completed_with_failures", "producerDone", "1", "currentRound", "1", "failedCount", fmt.Sprint(n)); err != nil {
		t.Fatal(err)
	}
	for i := 1; i <= n; i++ {
		rec := zset.FailureRecord{TaskID: fmt.Sprintf("task-%d", i), CardID: int64(i), ICCID: fmt.Sprintf("iccid-%d", i), ChanKey: "ch", TempKey: "template", Operation: "usage", FailureType: "mobile_busy"}
		payload, _ := json.Marshal(rec)
		if _, err := redis.Do(ctx, "HSET", failed, rec.TaskID, string(payload)); err != nil {
			t.Fatal(err)
		}
	}
}

// awaitTargetMaxRound waits for the handoff to create the target and returns
// the persisted MaxRound of the replayed Run.
func awaitTargetMaxRound(t *testing.T, svc *SimpleReplay, store *zset.Store, replayRunID string) int {
	t.Helper()
	ctx := context.Background()
	deadline := time.Now().Add(4 * time.Second)
	for time.Now().Before(deadline) {
		meta, err := store.GetRunMeta(ctx, replayRunID)
		if err == nil && meta.MaxRound > 0 && meta.ProducerDone {
			return meta.MaxRound
		}
		time.Sleep(20 * time.Millisecond)
	}
	meta, err := store.GetRunMeta(ctx, replayRunID)
	t.Fatalf("target never settled: %+v %v", meta, err)
	return 0
}

func TestReplayMaxRoundsPrefersRequestThenConfig(t *testing.T) {
	redis := testutil.Redis(t)
	ctx := context.Background()
	store, _ := zset.New(redis, "flow:")

	// Use a default that differs from DefaultReplayMaxRounds so the assertion
	// proves the injected config value is used, not the built-in constant.
	svc, err := NewSimpleReplayWithDefault(5, store)
	if err != nil {
		t.Fatal(err)
	}

	seedReplaySource(t, redis, store, "flow:default-source", 2)
	receipt, err := svc.Request(ctx, "flow:default-source", "42", 0)
	if err != nil {
		t.Fatal(err)
	}
	if got := awaitTargetMaxRound(t, svc, store, receipt.ReplayRunID); got != 5 {
		t.Fatalf("unspecified request must inherit config default 5, got %d", got)
	}

	seedReplaySource(t, redis, store, "flow:override-source", 2)
	override, err := svc.Request(ctx, "flow:override-source", "42", 7)
	if err != nil {
		t.Fatal(err)
	}
	if got := awaitTargetMaxRound(t, svc, store, override.ReplayRunID); got != 7 {
		t.Fatalf("explicit request must win over config, got %d", got)
	}
}

func TestReplayMaxRoundsRejectsOutOfRange(t *testing.T) {
	redis := testutil.Redis(t)
	ctx := context.Background()
	store, _ := zset.New(redis, "flow:")
	svc, _ := NewSimpleReplay(store)
	seedReplaySource(t, redis, store, "flow:source", 1)

	for _, requested := range []int{-1, MaxReplayRounds + 1} {
		if _, err := svc.Request(ctx, "flow:source", "42", requested); err != contract.ErrInvalidArgument {
			t.Fatalf("maxRounds=%d must be rejected, got %v", requested, err)
		}
	}
	// The rejected requests must not have reserved the source.
	if got, err := redis.Do(ctx, "HGET", "flow:{flow:source}:meta", "replayTargetId"); err == nil && got != nil && got.String() != "" {
		t.Fatalf("rejected request must not reserve the source: %v", got.String())
	}
}

// A worker restart re-enters through reconcile() without caller arguments, so
// the budget must survive on the reservation rather than come from the caller.
func TestReplayMaxRoundsSurvivesRestartRecovery(t *testing.T) {
	redis := testutil.Redis(t)
	ctx := context.Background()
	store, _ := zset.New(redis, "flow:")
	seedReplaySource(t, redis, store, "flow:source", 2)

	// Reserve with an explicit budget, then simulate a restart by building a
	// fresh service whose configured default differs from the reservation.
	first, _ := NewSimpleReplayWithDefault(1, store)
	receipt, err := first.Request(ctx, "flow:source", "42", 5)
	if err != nil {
		t.Fatal(err)
	}
	restarted, _ := NewSimpleReplayWithDefault(9, store)
	restarted.reconcile(ctx)

	if got := awaitTargetMaxRound(t, restarted, store, receipt.ReplayRunID); got != 5 {
		t.Fatalf("recovery must use the persisted budget 5, not the new default 9: got %d", got)
	}
}