package db

import (
	"errors"
	"regexp"
	"time"
)

var ErrNameTaken = errors.New("username has already been claimed")
var ErrNameDenied = errors.New("username is on the denylist")
var ErrNameInvalid = errors.New("username has invalid characters in it")

type PublicKey struct {
	ID        string     `json:"id"`
	UserID    string     `json:"user_id"`
	Key       string     `json:"key"`
	CreatedAt *time.Time `json:"created_at"`
}

type User struct {
	ID        string     `json:"id"`
	Name      string     `json:"name"`
	PublicKey *PublicKey `json:"public_key,omitempty"`
	CreatedAt *time.Time `json:"created_at"`
}

type Post struct {
	ID          string     `json:"id"`
	UserID      string     `json:"user_id"`
	Filename    string     `json:"filename"`
	Slug        string     `json:"slug"`
	Title       string     `json:"title"`
	Text        string     `json:"text"`
	Description string     `json:"description"`
	CreatedAt   *time.Time `json:"created_at"`
	PublishAt   *time.Time `json:"publish_at"`
	Username    string     `json:"username"`
	UpdatedAt   *time.Time `json:"updated_at"`
	Hidden      bool       `json:"hidden"`
	Views       int        `json:"views"`
	Space       string     `json:"space"`
	Score       string     `json:"score"`
}

type Paginate[T any] struct {
	Data  []T
	Total int
}

type Analytics struct {
	TotalUsers     int
	UsersLastMonth int
	TotalPosts     int
	PostsLastMonth int
	UsersWithPost  int
}

type PostAnalytics struct {
	ID       string
	PostID   string
	Views    int
	UpdateAt *time.Time
}

type Pager struct {
	Num  int
	Page int
}

type ErrMultiplePublicKeys struct{}

func (m *ErrMultiplePublicKeys) Error() string {
	return "there are multiple users with this public key, you must provide the username when using SSH: `ssh <user>@<domain>`\n"
}

var NameValidator = regexp.MustCompile("^[a-zA-Z0-9]{1,50}$")
var DenyList = []string{
	"admin",
	"abuse",
	"cgi",
	"ops",
	"help",
	"spec",
	"root",
	"new",
	"create",
	"www",
}

type DB interface {
	AddUser() (string, error)
	RemoveUsers(userIDs []string) error
	LinkUserKey(userID string, key string) error
	FindPublicKeyForKey(key string) (*PublicKey, error)
	FindKeysForUser(user *User) ([]*PublicKey, error)
	RemoveKeys(keyIDs []string) error

	FindSiteAnalytics(space string) (*Analytics, error)

	FindUsers() ([]*User, error)
	FindUserForName(name string) (*User, error)
	FindUserForNameAndKey(name string, key string) (*User, error)
	FindUserForKey(name string, key string) (*User, error)
	FindUser(userID string) (*User, error)
	ValidateName(name string) (bool, error)
	SetUserName(userID string, name string) error

	FindPosts() ([]*Post, error)
	FindPost(postID string) (*Post, error)
	FindPostsForUser(userID string, space string) ([]*Post, error)
	FindPostsBeforeDate(date *time.Time, space string) ([]*Post, error)
	FindUpdatedPostsForUser(userID string, space string) ([]*Post, error)
	FindPostWithFilename(filename string, userID string, space string) (*Post, error)
	FindPostWithSlug(slug string, userID string, space string) (*Post, error)
	FindAllPosts(pager *Pager, space string) (*Paginate[*Post], error)
	FindAllUpdatedPosts(pager *Pager, space string) (*Paginate[*Post], error)
	InsertPost(userID string, filename string, slug string, title string, text string, description string, publishAt *time.Time, hidden bool, space string) (*Post, error)
	UpdatePost(postID string, slug string, title string, text string, description string, publishAt *time.Time) (*Post, error)
	RemovePosts(postIDs []string) error

	ReplaceTagsForPost(tags []string, postID string) error
	FindUserPostsByTag(tag, userID, space string) ([]*Post, error)
	FindPostsByTag(tag, space string) ([]*Post, error)
	FindPopularTags() ([]string, error)

	AddViewCount(postID string) (int, error)

	Close() error
}