package projectindex

import (
	"context"
	"testing"
	"time"
)

// insertLegacyChapterSQL 用调用方给定的原始时间戳写入一行
// project_chapter，代表定宽布局之前持久化的行。
const insertLegacyChapterSQL = `INSERT INTO project_chapter
	(id, project_id, title, content, created_at, updated_at)
	VALUES (?, 'proj.1', '旧章节', '旧内容', ?, ?)`

func TestFormatTime_定宽_正常(t *testing.T) {
	t.Parallel()
	tests := []struct {
		name string
		at   time.Time
		want string
	}{
		{"一位小数秒", time.Date(2026, 9, 7, 3, 20, 5, 830000000, time.UTC), "2026-09-07T03:20:05.830000000Z"},
		{"纳秒", time.Date(2026, 9, 7, 3, 20, 5, 830978900, time.UTC), "2026-09-07T03:20:05.830978900Z"},
	}
	for _, tt := range tests {
		tt := tt
		t.Run(tt.name, func(t *testing.T) {
			t.Parallel()
			got := formatTime(tt.at)
			if got != tt.want {
				t.Errorf("formatTime = %q, want %q", got, tt.want)
			}
			if len(got) != storedTimeLen {
				t.Errorf("formatTime length = %d, want %d", len(got), storedTimeLen)
			}
		})
	}
}

// TestStore_ListChapters_变宽时间戳_排序 是 projectindex 针对变宽
// 时间戳缺陷的回归：RFC3339Nano 会把它们存成 ":05.83" 与
// ":05.8309789"，其文本顺序与时间顺序相反。
func TestStore_ListChapters_变宽时间戳_排序(t *testing.T) {
	t.Parallel()
	ctx := context.Background()
	s := newTestStore(t)

	sec := time.Date(2026, 9, 7, 3, 20, 5, 0, time.UTC)
	older := sec.Add(830 * time.Millisecond)
	newer := older.Add(978900 * time.Nanosecond)

	// 较新的章节先插入，因此只按 rowid 排序会把它放到
	// 最后：只有正确排序的 created_at 文本才会把它放在倒数第二。
	if err := s.AddChapter(ctx, "proj.1", Chapter{
		Title: "较晚", Content: "x", CreatedAt: newer, UpdatedAt: newer,
	}); err != nil {
		t.Fatalf("AddChapter(较晚): %v", err)
	}
	if err := s.AddChapter(ctx, "proj.1", Chapter{
		Title: "较早", Content: "y", CreatedAt: older, UpdatedAt: older,
	}); err != nil {
		t.Fatalf("AddChapter(较早): %v", err)
	}

	var raw string
	if err := s.db.QueryRowContext(ctx,
		`SELECT created_at FROM project_chapter WHERE title = ?`, "较早").Scan(&raw); err != nil {
		t.Fatalf("read stored created_at: %v", err)
	}
	if len(raw) != storedTimeLen {
		t.Errorf("stored created_at = %q (%d bytes), want fixed width %d", raw, len(raw), storedTimeLen)
	}

	list, err := s.ListChapters(ctx, "proj.1")
	if err != nil {
		t.Fatalf("ListChapters: %v", err)
	}
	if len(list) != 2 {
		t.Fatalf("ListChapters = %d chapters, want 2", len(list))
	}
	if list[0].Title != "较早" || list[1].Title != "较晚" {
		t.Errorf("titles = [%q %q], want oldest first (较早, 较晚)", list[0].Title, list[1].Title)
	}
}

// TestStore_ListChapters_同一时间戳_插入序 覆盖并列情形：连续的
// AddChapter 调用可能共享同一时钟刻，因此 rowid ASC 必须让它们保持
// 插入顺序。
func TestStore_ListChapters_同一时间戳_插入序(t *testing.T) {
	t.Parallel()
	ctx := context.Background()
	s := newTestStore(t)

	at := time.Date(2026, 9, 7, 3, 20, 5, 830978900, time.UTC)
	for _, title := range []string{"第一章", "第二章", "第三章"} {
		if err := s.AddChapter(ctx, "proj.1", Chapter{
			Title: title, Content: "内容", CreatedAt: at, UpdatedAt: at,
		}); err != nil {
			t.Fatalf("AddChapter(%s): %v", title, err)
		}
	}

	list, err := s.ListChapters(ctx, "proj.1")
	if err != nil {
		t.Fatalf("ListChapters: %v", err)
	}
	want := []string{"第一章", "第二章", "第三章"}
	if len(list) != len(want) {
		t.Fatalf("ListChapters = %d chapters, want %d", len(list), len(want))
	}
	for i, w := range want {
		if list[i].Title != w {
			t.Errorf("chapters[%d].Title = %q, want %q (rowid ASC)", i, list[i].Title, w)
		}
	}
}

// TestNew_归一化历史时间戳_正常 把旧的变宽数据写入两张
// 表，重新打开存储触发规范化，并检查修复后的文本
// 以及幂等性与无法解析行的跳过。
func TestNew_归一化历史时间戳_正常(t *testing.T) {
	t.Parallel()
	ctx := context.Background()
	s := newTestStore(t)

	const legacy = "2026-09-07T03:20:05.83Z"
	if _, err := s.db.ExecContext(ctx, `INSERT INTO project (id, title, desc, created_at, updated_at)
		VALUES ('proj.legacy', 'T', '', ?, ?)`, legacy, legacy); err != nil {
		t.Fatalf("insert legacy project: %v", err)
	}
	if _, err := s.db.ExecContext(ctx, insertLegacyChapterSQL, "ch.legacy", legacy, legacy); err != nil {
		t.Fatalf("insert legacy chapter: %v", err)
	}
	if _, err := s.db.ExecContext(ctx, insertLegacyChapterSQL, "ch.broken", "not-a-time", "not-a-time"); err != nil {
		t.Fatalf("insert unparseable chapter: %v", err)
	}

	// 重新打开会规范化两张表；无法解析的值不得阻塞它。
	if _, err := New(ctx, s.db, testLogger()); err != nil {
		t.Fatalf("New (normalize): %v", err)
	}

	const want = "2026-09-07T03:20:05.830000000Z"
	for _, tc := range []struct{ name, query, id string }{
		{"project", `SELECT created_at FROM project WHERE id = ?`, "proj.legacy"},
		{"project_chapter", `SELECT created_at FROM project_chapter WHERE id = ?`, "ch.legacy"},
	} {
		var raw string
		if err := s.db.QueryRowContext(ctx, tc.query, tc.id).Scan(&raw); err != nil {
			t.Fatalf("read %s created_at: %v", tc.name, err)
		}
		if raw != want {
			t.Errorf("%s created_at = %q, want %q", tc.name, raw, want)
		}
	}

	var broken string
	if err := s.db.QueryRowContext(ctx,
		`SELECT created_at FROM project_chapter WHERE id = ?`, "ch.broken").Scan(&broken); err != nil {
		t.Fatalf("read unparseable created_at: %v", err)
	}
	if broken != "not-a-time" {
		t.Errorf("unparseable created_at = %q, want it left as is", broken)
	}

	// 再次打开必须是空操作。
	if _, err := New(ctx, s.db, testLogger()); err != nil {
		t.Fatalf("New (second pass): %v", err)
	}
	var again string
	if err := s.db.QueryRowContext(ctx,
		`SELECT created_at FROM project WHERE id = ?`, "proj.legacy").Scan(&again); err != nil {
		t.Fatalf("read created_at after second open: %v", err)
	}
	if again != want {
		t.Errorf("second open changed created_at: %q -> %q", want, again)
	}

	got, err := s.GetProject(ctx, "proj.legacy")
	if err != nil {
		t.Fatalf("GetProject: %v", err)
	}
	wantTime := time.Date(2026, 9, 7, 3, 20, 5, 830000000, time.UTC)
	if !got.CreatedAt.Equal(wantTime) {
		t.Errorf("project created_at = %v, want %v", got.CreatedAt, wantTime)
	}
}