package api

import (
	"encoding/json"
	"testing"

	"github.com/ponzischeme89/memby/server/internal/store"
)

func readyReq(itemID, mediaType string) store.SurfacedReadyRequest {
	return store.SurfacedReadyRequest{MediaType: mediaType, ItemID: itemID, Title: itemID}
}

func isStamped(t *testing.T, raw json.RawMessage) bool {
	t.Helper()
	var item struct {
		Ready bool   `json:"MembyRequestReady"`
		Label string `json:"MembyRequestReadyLabel"`
	}
	if err := json.Unmarshal(raw, &item); err != nil {
		t.Fatalf("unmarshal: %v", err)
	}
	return item.Ready && item.Label == requestReadyLabel
}

// The overwhelmingly common case: nobody is waiting on anything, so the row is untouched.
func TestMergeRequestReadyNoArrivalsIsANoOp(t *testing.T) {
	items := []json.RawMessage{resumeItem(t, "film", "", "2026-08-01T20:00:00Z")}
	got := mergeRequestReady(items, nil, nil)
	if !equalIDs(mergedIDs(t, got), []string{"film"}) {
		t.Fatalf("ids = %v", mergedIDs(t, got))
	}
	if isStamped(t, got[0]) {
		t.Fatal("item stamped with no arrivals")
	}
}

// An arrival not in the row is prepended and tagged.
func TestMergeRequestReadyPrependsMissingTitle(t *testing.T) {
	items := []json.RawMessage{resumeItem(t, "film", "", "2026-08-01T20:00:00Z")}
	surfaced := []store.SurfacedReadyRequest{readyReq("new-movie", "movie")}
	fetched := map[string]json.RawMessage{
		"new-movie": continueRaw(t, map[string]any{"Id": "new-movie", "Type": "Movie"}),
	}

	got := mergeRequestReady(items, surfaced, fetched)
	if want := []string{"new-movie", "film"}; !equalIDs(mergedIDs(t, got), want) {
		t.Fatalf("ids = %v, want %v", mergedIDs(t, got), want)
	}
	if !isStamped(t, got[0]) {
		t.Fatal("prepended card not stamped")
	}
	if isStamped(t, got[1]) {
		t.Fatal("existing card wrongly stamped")
	}
}

// Newest arrival first when several are prepended (surfaced is ordered newest first).
func TestMergeRequestReadyKeepsNewestArrivalFirst(t *testing.T) {
	items := []json.RawMessage{resumeItem(t, "film", "", "2026-08-01T20:00:00Z")}
	surfaced := []store.SurfacedReadyRequest{readyReq("newer", "movie"), readyReq("older", "movie")}
	fetched := map[string]json.RawMessage{
		"newer": continueRaw(t, map[string]any{"Id": "newer", "Type": "Movie"}),
		"older": continueRaw(t, map[string]any{"Id": "older", "Type": "Movie"}),
	}

	got := mergedIDs(t, mergeRequestReady(items, surfaced, fetched))
	if want := []string{"newer", "older", "film"}; !equalIDs(got, want) {
		t.Fatalf("ids = %v, want %v", got, want)
	}
}

// A surfaced title already in Continue Watching — by its own id, or as the series an
// episode belongs to — is tagged in place, never duplicated.
func TestMergeRequestReadyTagsExistingCardInPlace(t *testing.T) {
	items := []json.RawMessage{
		resumeItem(t, "s1e3", "severance", "2026-08-06T19:00:00Z"),
		resumeItem(t, "the-film", "", "2026-08-01T20:00:00Z"),
	}
	surfaced := []store.SurfacedReadyRequest{
		readyReq("severance", "series"),
		readyReq("the-film", "movie"),
	}

	got := mergeRequestReady(items, surfaced, nil)
	if want := []string{"s1e3", "the-film"}; !equalIDs(mergedIDs(t, got), want) {
		t.Fatalf("ids = %v, want %v", mergedIDs(t, got), want)
	}
	if !isStamped(t, got[0]) || !isStamped(t, got[1]) {
		t.Fatal("existing cards not tagged in place")
	}
}

// A fetch that returned nothing for an arrival degrades to leaving it out rather than
// inserting a blank card.
func TestMergeRequestReadyDropsUnfetchableArrival(t *testing.T) {
	items := []json.RawMessage{resumeItem(t, "film", "", "2026-08-01T20:00:00Z")}
	surfaced := []store.SurfacedReadyRequest{readyReq("gone", "movie")}

	got := mergeRequestReady(items, surfaced, map[string]json.RawMessage{})
	if !equalIDs(mergedIDs(t, got), []string{"film"}) {
		t.Fatalf("ids = %v", mergedIDs(t, got))
	}
}

func TestStampRequestReadyPreservesOtherFields(t *testing.T) {
	raw := continueRaw(t, map[string]any{"Id": "x", "Name": "Keep me", "Type": "Movie"})
	stamped := stampRequestReady(raw)
	var item struct {
		Name  string `json:"Name"`
		Ready bool   `json:"MembyRequestReady"`
	}
	if err := json.Unmarshal(stamped, &item); err != nil {
		t.Fatalf("unmarshal: %v", err)
	}
	if item.Name != "Keep me" || !item.Ready {
		t.Fatalf("stamp lost fields: %+v", item)
	}
}