package db

import (
	"database/sql"
	"testing"
)

func openTestDB(t *testing.T) *DB {
	t.Helper()
	d, err := Open(":memory:")
	if err != nil {
		t.Fatalf("open test db: %v", err)
	}
	t.Cleanup(func() { d.Close() })
	return d
}

func TestAddAndGetRedirect(t *testing.T) {
	d := openTestDB(t)

	if err := d.AddRedirect("old-slug", "new-slug"); err != nil {
		t.Fatalf("AddRedirect: %v", err)
	}

	got, err := d.GetRedirect("old-slug")
	if err != nil {
		t.Fatalf("GetRedirect: %v", err)
	}
	if got != "new-slug" {
		t.Errorf("got %q, want %q", got, "new-slug")
	}
}

func TestGetRedirect_NotFound(t *testing.T) {
	d := openTestDB(t)

	_, err := d.GetRedirect("missing")
	if err != sql.ErrNoRows {
		t.Errorf("expected sql.ErrNoRows, got %v", err)
	}
}

func TestCollapseRedirects(t *testing.T) {
	d := openTestDB(t)

	if err := d.AddRedirect("a", "b"); err != nil {
		t.Fatalf("AddRedirect: %v", err)
	}
	if err := d.CollapseRedirects("b", "c"); err != nil {
		t.Fatalf("CollapseRedirects: %v", err)
	}

	got, err := d.GetRedirect("a")
	if err != nil {
		t.Fatalf("GetRedirect: %v", err)
	}
	if got != "c" {
		t.Errorf("got %q, want %q", got, "c")
	}
}

func TestAddRedirect_Upsert(t *testing.T) {
	d := openTestDB(t)

	if err := d.AddRedirect("old", "first"); err != nil {
		t.Fatalf("AddRedirect first: %v", err)
	}
	if err := d.AddRedirect("old", "second"); err != nil {
		t.Fatalf("AddRedirect second: %v", err)
	}

	got, err := d.GetRedirect("old")
	if err != nil {
		t.Fatalf("GetRedirect: %v", err)
	}
	if got != "second" {
		t.Errorf("got %q, want %q", got, "second")
	}
}

func TestRenamePost(t *testing.T) {
	d := openTestDB(t)

	original := PostRecord{
		Slug:      "original-slug",
		Title:     "My Post",
		Date:      "2026-04-04",
		Tags:      []string{"go"},
		Draft:     false,
		Blocks:    `[{"type":"paragraph","data":{"text":"hello"}}]`,
		UpdatedAt: 1000000,
	}
	if err := d.UpsertPost(original); err != nil {
		t.Fatalf("UpsertPost: %v", err)
	}

	if err := d.RenamePost("original-slug", "new-slug"); err != nil {
		t.Fatalf("RenamePost: %v", err)
	}

	got, err := d.GetPostBySlug("new-slug")
	if err != nil {
		t.Fatalf("GetPost new-slug: %v", err)
	}
	if got.Title != "My Post" {
		t.Errorf("title: got %q, want %q", got.Title, "My Post")
	}

	_, err = d.GetPostBySlug("original-slug")
	if err == nil {
		t.Error("expected old slug to be deleted, but GetPost returned no error")
	}

	toSlug, err := d.GetRedirect("original-slug")
	if err != nil {
		t.Fatalf("GetRedirect: %v", err)
	}
	if toSlug != "new-slug" {
		t.Errorf("redirect: got %q, want %q", toSlug, "new-slug")
	}
}

func TestRenameAndUpsertPost(t *testing.T) {
	d := openTestDB(t)

	if err := d.UpsertPost(PostRecord{Slug: "old", Title: "Old Title", Date: "2026-01-01", Blocks: "[]", UpdatedAt: 1}); err != nil {
		t.Fatalf("UpsertPost: %v", err)
	}

	updated := PostRecord{
		Slug:      "new",
		Title:     "New Title",
		Date:      "2026-04-04",
		Tags:      []string{"go"},
		Blocks:    "[]",
		UpdatedAt: 2,
	}
	if err := d.RenameAndUpsertPost("old", updated); err != nil {
		t.Fatalf("RenameAndUpsertPost: %v", err)
	}

	got, err := d.GetPostBySlug("new")
	if err != nil {
		t.Fatalf("GetPost new: %v", err)
	}
	if got.Title != "New Title" {
		t.Errorf("title: got %q, want %q", got.Title, "New Title")
	}
	if got.Date != "2026-04-04" {
		t.Errorf("date: got %q, want %q", got.Date, "2026-04-04")
	}

	if _, err := d.GetPostBySlug("old"); err == nil {
		t.Error("expected old slug to be deleted")
	}

	toSlug, err := d.GetRedirect("old")
	if err != nil {
		t.Fatalf("GetRedirect: %v", err)
	}
	if toSlug != "new" {
		t.Errorf("redirect: got %q, want %q", toSlug, "new")
	}
}

func TestRenamePost_CollapsesChain(t *testing.T) {
	d := openTestDB(t)

	if err := d.UpsertPost(PostRecord{Slug: "b", Title: "B", Blocks: "[]", UpdatedAt: 1}); err != nil {
		t.Fatalf("UpsertPost: %v", err)
	}
	if err := d.AddRedirect("a", "b"); err != nil {
		t.Fatalf("AddRedirect: %v", err)
	}
	if err := d.RenamePost("b", "c"); err != nil {
		t.Fatalf("RenamePost: %v", err)
	}

	got, err := d.GetRedirect("a")
	if err != nil {
		t.Fatalf("GetRedirect a: %v", err)
	}
	if got != "c" {
		t.Errorf("chain collapse: got %q, want %q", got, "c")
	}
}