// Package store 保存应用自身的数据（设置、会话、API 令牌）。笔记内容不在这里，见 vault。
package store

import (
	"database/sql"
	"errors"
	"rawmark/internal/i18n"
	"time"

	_ "modernc.org/sqlite"
)

type Store struct{ db *sql.DB }

const schema = `
CREATE TABLE IF NOT EXISTS settings (
  key   TEXT PRIMARY KEY,
  value TEXT NOT NULL
);
CREATE TABLE IF NOT EXISTS sessions (
  token_hash TEXT PRIMARY KEY,
  created_at INTEGER NOT NULL,
  expires_at INTEGER NOT NULL
);
CREATE TABLE IF NOT EXISTS resource_tickets (
  token_hash TEXT PRIMARY KEY,
  session_hash TEXT NOT NULL,
  kind TEXT NOT NULL,
  resource TEXT NOT NULL,
  revision TEXT NOT NULL,
  expires_at INTEGER NOT NULL
);
CREATE INDEX IF NOT EXISTS resource_tickets_expiry ON resource_tickets(expires_at);
CREATE TABLE IF NOT EXISTS api_tokens (
  id           TEXT PRIMARY KEY,
  name         TEXT NOT NULL,
  token_hash   TEXT NOT NULL UNIQUE,
  scope        TEXT NOT NULL,
  created_at   INTEGER NOT NULL,
  last_used_at INTEGER NOT NULL DEFAULT 0
);
`

func Open(path string) (*Store, error) {
	db, err := sql.Open("sqlite", "file:"+path+"?_pragma=journal_mode(WAL)&_pragma=busy_timeout(5000)&_pragma=foreign_keys(1)")
	if err != nil {
		return nil, err
	}
	if _, err := db.Exec(schema); err != nil {
		db.Close()
		return nil, i18n.New("could_not_initialize_database_w_208f9e", err)
	}
	return &Store{db: db}, nil
}

func (s *Store) Close() error { return s.db.Close() }

// Setting 读取设置项；不存在时 ok 为 false
func (s *Store) Setting(key string) (value string, ok bool, err error) {
	err = s.db.QueryRow(`SELECT value FROM settings WHERE key = ?`, key).Scan(&value)
	if errors.Is(err, sql.ErrNoRows) {
		return "", false, nil
	}
	return value, err == nil, err
}

func (s *Store) SetSetting(key, value string) error {
	_, err := s.db.Exec(`INSERT INTO settings (key, value) VALUES (?, ?) ON CONFLICT(key) DO UPDATE SET value = excluded.value`, key, value)
	return err
}

// SetSettingIfAbsent 仅在设置项不存在时写入，返回是否写入成功（用于首次初始化，防止并发重复设置）
func (s *Store) SetSettingIfAbsent(key, value string) (bool, error) {
	res, err := s.db.Exec(`INSERT INTO settings (key, value) VALUES (?, ?) ON CONFLICT(key) DO NOTHING`, key, value)
	if err != nil {
		return false, err
	}
	n, err := res.RowsAffected()
	return n == 1, err
}

func (s *Store) CreateSession(tokenHash string, expires time.Time) error {
	_, err := s.db.Exec(`INSERT INTO sessions (token_hash, created_at, expires_at) VALUES (?, ?, ?)`,
		tokenHash, time.Now().Unix(), expires.Unix())
	return err
}

// SessionExpiry 只读取有效会话，不延长固定有效期。
func (s *Store) SessionExpiry(tokenHash string, now time.Time) (time.Time, bool, error) {
	var expires int64
	err := s.db.QueryRow(`SELECT expires_at FROM sessions WHERE token_hash = ? AND expires_at > ?`, tokenHash, now.Unix()).Scan(&expires)
	if errors.Is(err, sql.ErrNoRows) {
		return time.Time{}, false, nil
	}
	return time.Unix(expires, 0).UTC(), err == nil, err
}

func (s *Store) DeleteSession(tokenHash string) error {
	_, err := s.db.Exec(`DELETE FROM sessions WHERE token_hash = ?`, tokenHash)
	return err
}

// DeleteOtherSessions 删除除 keepHash 之外的所有会话（修改密码后让其他设备重新登录）
func (s *Store) DeleteOtherSessions(keepHash string) error {
	_, err := s.db.Exec(`DELETE FROM sessions WHERE token_hash <> ?`, keepHash)
	return err
}

func (s *Store) DeleteExpiredSessions() error {
	_, err := s.db.Exec(`DELETE FROM sessions WHERE expires_at <= ?`, time.Now().Unix())
	if err != nil {
		return err
	}
	_, err = s.db.Exec(`DELETE FROM resource_tickets WHERE expires_at <= ? OR NOT EXISTS (SELECT 1 FROM sessions WHERE sessions.token_hash = resource_tickets.session_hash)`, time.Now().Unix())
	return err
}

// ---- API 令牌 ----

// APIToken 为自动化调用的访问令牌，只保存哈希。Scope 为 read 或 write
type APIToken struct {
	ID         string `json:"id"`
	Name       string `json:"name"`
	Hash       string `json:"-"`
	Scope      string `json:"scope"`
	CreatedAt  int64  `json:"createdAt"`
	LastUsedAt int64  `json:"lastUsedAt"`
}

func (s *Store) CreateAPIToken(t APIToken) error {
	_, err := s.db.Exec(`INSERT INTO api_tokens (id, name, token_hash, scope, created_at) VALUES (?, ?, ?, ?, ?)`,
		t.ID, t.Name, t.Hash, t.Scope, t.CreatedAt)
	return err
}

func (s *Store) APITokens() ([]APIToken, error) {
	rows, err := s.db.Query(`SELECT id, name, scope, created_at, last_used_at FROM api_tokens ORDER BY created_at DESC`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	out := []APIToken{}
	for rows.Next() {
		var t APIToken
		if err := rows.Scan(&t.ID, &t.Name, &t.Scope, &t.CreatedAt, &t.LastUsedAt); err != nil {
			return nil, err
		}
		out = append(out, t)
	}
	return out, rows.Err()
}

// UseAPIToken 按哈希查找令牌并记录使用时间；不存在时 ok 为 false
func (s *Store) UseAPIToken(hash string, now int64) (scope string, ok bool, err error) {
	err = s.db.QueryRow(`UPDATE api_tokens SET last_used_at = ? WHERE token_hash = ? RETURNING scope`, now, hash).Scan(&scope)
	if errors.Is(err, sql.ErrNoRows) {
		return "", false, nil
	}
	return scope, err == nil, err
}

func (s *Store) DeleteAPIToken(id string) (bool, error) {
	res, err := s.db.Exec(`DELETE FROM api_tokens WHERE id = ?`, id)
	if err != nil {
		return false, err
	}
	n, err := res.RowsAffected()
	return n == 1, err
}