// SPDX-FileCopyrightText: Copyright The Miniflux Authors. All rights reserved.
// SPDX-License-Identifier: Apache-2.0

package storage // import "miniflux.app/v2/internal/storage"

import (
	"crypto/rand"
	"database/sql"
	"fmt"
	"time"

	"miniflux.app/v2/internal/model"
)

// CreateAppSessionWithUserPrefs creates a new application session with the given user preferences.
func (s *Storage) CreateAppSessionWithUserPrefs(userID int64) (*model.Session, error) {
	user, err := s.UserByID(userID)
	if err != nil {
		return nil, err
	}

	session := model.Session{
		ID: rand.Text(),
		Data: &model.SessionData{
			CSRF:     rand.Text(),
			Theme:    user.Theme,
			Language: user.Language,
		},
	}

	return s.createAppSession(&session)
}

// CreateAppSession creates a new application session.
func (s *Storage) CreateAppSession() (*model.Session, error) {
	session := model.Session{
		ID: rand.Text(),
		Data: &model.SessionData{
			CSRF: rand.Text(),
		},
	}

	return s.createAppSession(&session)
}

func (s *Storage) createAppSession(session *model.Session) (*model.Session, error) {
	query := `INSERT INTO sessions (id, data) VALUES ($1, $2)`
	_, err := s.db.Exec(query, session.ID, session.Data)
	if err != nil {
		return nil, fmt.Errorf(`store: unable to create app session: %v`, err)
	}

	return session, nil
}

// UpdateAppSessionField updates only one session field.
func (s *Storage) UpdateAppSessionField(sessionID, field string, value any) error {
	query := `
		UPDATE
			sessions
		SET
			data = jsonb_set(data, '{%s}', to_jsonb($1::text), true)
		WHERE
			id=$2
	`
	_, err := s.db.Exec(fmt.Sprintf(query, field), value, sessionID)
	if err != nil {
		return fmt.Errorf(`store: unable to update session field: %v`, err)
	}

	return nil
}

func (s *Storage) UpdateAppSessionObjectField(sessionID, field string, value any) error {
	query := `
		UPDATE
			sessions
		SET
			data = jsonb_set(data, '{%s}', $1, true)
		WHERE
			id=$2
	`
	_, err := s.db.Exec(fmt.Sprintf(query, field), value, sessionID)
	if err != nil {
		return fmt.Errorf(`store: unable to update session field: %v`, err)
	}

	return nil
}

// AppSession returns the given session.
func (s *Storage) AppSession(id string) (*model.Session, error) {
	var session model.Session

	query := "SELECT id, data FROM sessions WHERE id=$1"
	err := s.db.QueryRow(query, id).Scan(
		&session.ID,
		&session.Data,
	)

	switch {
	case err == sql.ErrNoRows:
		return nil, fmt.Errorf(`store: session not found: %s`, id)
	case err != nil:
		return nil, fmt.Errorf(`store: unable to fetch session: %v`, err)
	default:
		return &session, nil
	}
}

// FlushAllSessions removes all sessions from the database.
func (s *Storage) FlushAllSessions() (err error) {
	_, err = s.db.Exec(`DELETE FROM user_sessions`)
	if err != nil {
		return err
	}

	_, err = s.db.Exec(`DELETE FROM sessions`)
	if err != nil {
		return err
	}

	return nil
}

// CleanOldSessions removes sessions older than specified interval (24h minimum).
func (s *Storage) CleanOldSessions(interval time.Duration) int64 {
	query := `
		DELETE FROM
			sessions
		WHERE
			created_at < now() - $1::interval
	`

	days := max(int(interval/(24*time.Hour)), 1)

	result, err := s.db.Exec(query, fmt.Sprintf("%d days", days))
	if err != nil {
		return 0
	}

	n, _ := result.RowsAffected()
	return n
}
