package relay

import (
	"os"
	"testing"
	"time"
)

func newTestFeedMailbox(t *testing.T) *FeedMailbox {
	t.Helper()
	dir, err := os.MkdirTemp("", "dchain-feedtest-*")
	if err != nil {
		t.Fatalf("MkdirTemp: %v", err)
	}
	fm, err := OpenFeedMailbox(dir, 24*time.Hour)
	if err != nil {
		_ = os.RemoveAll(dir)
		t.Fatalf("OpenFeedMailbox: %v", err)
	}
	t.Cleanup(func() {
		_ = fm.Close()
		for i := 0; i < 20; i++ {
			if err := os.RemoveAll(dir); err == nil {
				return
			}
			time.Sleep(10 * time.Millisecond)
		}
	})
	return fm
}

// TestFeedMailboxStoreAndGet: store round-trips content + metadata.
func TestFeedMailboxStoreAndGet(t *testing.T) {
	fm := newTestFeedMailbox(t)
	post := &FeedPost{
		PostID:  "p1",
		Author:  "authorhex",
		Content: "Hello #world from #dchain",
	}
	tags, err := fm.Store(post, 12345)
	if err != nil {
		t.Fatalf("Store: %v", err)
	}
	wantTags := []string{"world", "dchain"}
	if len(tags) != len(wantTags) {
		t.Fatalf("Store returned %v, want %v", tags, wantTags)
	}
	for i := range wantTags {
		if tags[i] != wantTags[i] {
			t.Errorf("Store tag[%d]: got %q, want %q", i, tags[i], wantTags[i])
		}
	}

	got, err := fm.Get("p1")
	if err != nil || got == nil {
		t.Fatalf("Get: got %v err=%v", got, err)
	}
	if got.Content != post.Content {
		t.Errorf("content: got %q, want %q", got.Content, post.Content)
	}
	if got.CreatedAt != 12345 {
		t.Errorf("created_at: got %d, want 12345", got.CreatedAt)
	}
	if len(got.Hashtags) != 2 {
		t.Errorf("hashtags: got %v, want [world dchain]", got.Hashtags)
	}
}

// TestFeedMailboxTooLarge: rejects over-quota content.
func TestFeedMailboxTooLarge(t *testing.T) {
	fm := newTestFeedMailbox(t)
	big := make([]byte, MaxPostBodySize+1)
	post := &FeedPost{
		PostID:     "big1",
		Author:     "a",
		Attachment: big,
	}
	if _, err := fm.Store(post, 0); err != ErrPostTooLarge {
		t.Fatalf("Store huge post: got %v, want ErrPostTooLarge", err)
	}
}

// TestFeedMailboxHashtagIndex: hashtags are searchable + dedup + case-normalised.
func TestFeedMailboxHashtagIndex(t *testing.T) {
	fm := newTestFeedMailbox(t)

	p1 := &FeedPost{PostID: "p1", Author: "a", Content: "post about #Go"}
	p2 := &FeedPost{PostID: "p2", Author: "b", Content: "Also #go programming"}
	p3 := &FeedPost{PostID: "p3", Author: "a", Content: "#Rust too"}

	if _, err := fm.Store(p1, 1000); err != nil {
		t.Fatal(err)
	}
	if _, err := fm.Store(p2, 2000); err != nil {
		t.Fatal(err)
	}
	if _, err := fm.Store(p3, 3000); err != nil {
		t.Fatal(err)
	}

	// #go is case-insensitive, should return both posts newest-first.
	ids, err := fm.PostsByHashtag("#Go", 10)
	if err != nil {
		t.Fatal(err)
	}
	if len(ids) != 2 || ids[0] != "p2" || ids[1] != "p1" {
		t.Errorf("PostsByHashtag(Go): got %v, want [p2 p1]", ids)
	}

	ids, _ = fm.PostsByHashtag("rust", 10)
	if len(ids) != 1 || ids[0] != "p3" {
		t.Errorf("PostsByHashtag(rust): got %v, want [p3]", ids)
	}
}

// TestFeedMailboxViewCounter: increments + reads.
func TestFeedMailboxViewCounter(t *testing.T) {
	fm := newTestFeedMailbox(t)
	fm.Store(&FeedPost{PostID: "p", Author: "a", Content: "hi"}, 10)

	for i := 1; i <= 5; i++ {
		n, err := fm.IncrementView("p")
		if err != nil {
			t.Fatal(err)
		}
		if n != uint64(i) {
			t.Errorf("IncrementView #%d: got %d, want %d", i, n, i)
		}
	}
	if n, _ := fm.ViewCount("p"); n != 5 {
		t.Errorf("ViewCount: got %d, want 5", n)
	}
}

// TestFeedMailboxByAuthor: author chrono index returns newest first.
func TestFeedMailboxByAuthor(t *testing.T) {
	fm := newTestFeedMailbox(t)
	fm.Store(&FeedPost{PostID: "old", Author: "a", Content: "one"}, 100)
	fm.Store(&FeedPost{PostID: "new", Author: "a", Content: "two"}, 500)
	fm.Store(&FeedPost{PostID: "mid", Author: "a", Content: "three"}, 300)
	fm.Store(&FeedPost{PostID: "other", Author: "b", Content: "four"}, 400)

	ids, err := fm.PostsByAuthor("a", 10)
	if err != nil {
		t.Fatal(err)
	}
	want := []string{"new", "mid", "old"}
	if len(ids) != len(want) {
		t.Fatalf("len: got %d, want %d (%v)", len(ids), len(want), ids)
	}
	for i := range want {
		if ids[i] != want[i] {
			t.Errorf("pos %d: got %q want %q", i, ids[i], want[i])
		}
	}
}

// TestFeedMailboxDelete: removes body + indices.
func TestFeedMailboxDelete(t *testing.T) {
	fm := newTestFeedMailbox(t)
	fm.Store(&FeedPost{PostID: "x", Author: "a", Content: "doomed #go"}, 100)

	if err := fm.Delete("x"); err != nil {
		t.Fatalf("Delete: %v", err)
	}
	if got, _ := fm.Get("x"); got != nil {
		t.Errorf("Get after delete: got %v, want nil", got)
	}
	if ids, _ := fm.PostsByHashtag("go", 10); len(ids) != 0 {
		t.Errorf("hashtag index: got %v, want []", ids)
	}
	if ids, _ := fm.PostsByAuthor("a", 10); len(ids) != 0 {
		t.Errorf("author index: got %v, want []", ids)
	}
}

// TestFeedMailboxRecentIDs: filters by window, sorts newest first.
func TestFeedMailboxRecentIDs(t *testing.T) {
	fm := newTestFeedMailbox(t)
	now := time.Now().Unix()
	// p1 1 hour old, p2 5 hours old, p3 50 hours old.
	fm.Store(&FeedPost{PostID: "p1", Author: "a", Content: "a"}, now-3600)
	fm.Store(&FeedPost{PostID: "p2", Author: "b", Content: "b"}, now-5*3600)
	fm.Store(&FeedPost{PostID: "p3", Author: "c", Content: "c"}, now-50*3600)

	// 6-hour window: p1 and p2 only.
	ids, err := fm.RecentPostIDs(6*3600, 100)
	if err != nil {
		t.Fatal(err)
	}
	if len(ids) != 2 {
		t.Errorf("RecentPostIDs(6h): got %v, want 2 posts", ids)
	}
	// Newest first.
	if ids[0] != "p1" {
		t.Errorf("first post: got %s, want p1", ids[0])
	}
}