package sdk

import (
	"strings"

	"github.com/drakkan/sftpgo/v2/util"
)

// Web Client restrictions
const (
	WebClientPubKeyChangeDisabled = "publickey-change-disabled"
)

var (
	// WebClientOptions defines the available options for the web client interface
	WebClientOptions = []string{WebClientPubKeyChangeDisabled}
)

// TLSUsername defines the TLS certificate attribute to use as username
type TLSUsername string

// Supported certificate attributes to use as username
const (
	TLSUsernameNone TLSUsername = "None"
	TLSUsernameCN   TLSUsername = "CommonName"
)

// DirectoryPermissions defines permissions for a directory virtual path
type DirectoryPermissions struct {
	Path        string
	Permissions []string
}

// HasPerm returns true if the directory has the specified permissions
func (d *DirectoryPermissions) HasPerm(perm string) bool {
	return util.IsStringInSlice(perm, d.Permissions)
}

// PatternsFilter defines filters based on shell like patterns.
// These restrictions do not apply to files listing for performance reasons, so
// a denied file cannot be downloaded/overwritten/renamed but will still be
// in the list of files.
// System commands such as Git and rsync interacts with the filesystem directly
// and they are not aware about these restrictions so they are not allowed
// inside paths with extensions filters
type PatternsFilter struct {
	// Virtual path, if no other specific filter is defined, the filter apply for
	// sub directories too.
	// For example if filters are defined for the paths "/" and "/sub" then the
	// filters for "/" are applied for any file outside the "/sub" directory
	Path string `json:"path"`
	// files with these, case insensitive, patterns are allowed.
	// Denied file patterns are evaluated before the allowed ones
	AllowedPatterns []string `json:"allowed_patterns,omitempty"`
	// files with these, case insensitive, patterns are not allowed.
	// Denied file patterns are evaluated before the allowed ones
	DeniedPatterns []string `json:"denied_patterns,omitempty"`
}

// GetCommaSeparatedPatterns returns the first non empty patterns list comma separated
func (p *PatternsFilter) GetCommaSeparatedPatterns() string {
	if len(p.DeniedPatterns) > 0 {
		return strings.Join(p.DeniedPatterns, ",")
	}
	return strings.Join(p.AllowedPatterns, ",")
}

// IsDenied returns true if the patterns has one or more denied patterns
func (p *PatternsFilter) IsDenied() bool {
	return len(p.DeniedPatterns) > 0
}

// IsAllowed returns true if the patterns has one or more allowed patterns
func (p *PatternsFilter) IsAllowed() bool {
	return len(p.AllowedPatterns) > 0
}

// HooksFilter defines user specific overrides for global hooks
type HooksFilter struct {
	ExternalAuthDisabled  bool `json:"external_auth_disabled"`
	PreLoginDisabled      bool `json:"pre_login_disabled"`
	CheckPasswordDisabled bool `json:"check_password_disabled"`
}

// UserFilters defines additional restrictions for a user
// TODO: rename to UserOptions in v3
type UserFilters struct {
	// only clients connecting from these IP/Mask are allowed.
	// IP/Mask must be in CIDR notation as defined in RFC 4632 and RFC 4291
	// for example "192.0.2.0/24" or "2001:db8::/32"
	AllowedIP []string `json:"allowed_ip,omitempty"`
	// clients connecting from these IP/Mask are not allowed.
	// Denied rules will be evaluated before allowed ones
	DeniedIP []string `json:"denied_ip,omitempty"`
	// these login methods are not allowed.
	// If null or empty any available login method is allowed
	DeniedLoginMethods []string `json:"denied_login_methods,omitempty"`
	// these protocols are not allowed.
	// If null or empty any available protocol is allowed
	DeniedProtocols []string `json:"denied_protocols,omitempty"`
	// filter based on shell patterns.
	// Please note that these restrictions can be easily bypassed.
	FilePatterns []PatternsFilter `json:"file_patterns,omitempty"`
	// max size allowed for a single upload, 0 means unlimited
	MaxUploadFileSize int64 `json:"max_upload_file_size,omitempty"`
	// TLS certificate attribute to use as username.
	// For FTP clients it must match the name provided using the
	// "USER" command
	TLSUsername TLSUsername `json:"tls_username,omitempty"`
	// user specific hook overrides
	Hooks HooksFilter `json:"hooks,omitempty"`
	// Disable checks for existence and automatic creation of home directory
	// and virtual folders.
	// SFTPGo requires that the user's home directory, virtual folder root,
	// and intermediate paths to virtual folders exist to work properly.
	// If you already know that the required directories exist, disabling
	// these checks will speed up login.
	// You could, for example, disable these checks after the first login
	DisableFsChecks bool `json:"disable_fs_checks,omitempty"`
	// WebClient related configuration options
	WebClient []string `json:"web_client,omitempty"`
}

type BaseUser struct {
	// Data provider unique identifier
	ID int64 `json:"id"`
	// 1 enabled, 0 disabled (login is not allowed)
	Status int `json:"status"`
	// Username
	Username string `json:"username"`
	// Account expiration date as unix timestamp in milliseconds. An expired account cannot login.
	// 0 means no expiration
	ExpirationDate int64 `json:"expiration_date"`
	// Password used for password authentication.
	// For users created using SFTPGo REST API the password is be stored using bcrypt or argon2id hashing algo.
	// Checking passwords stored with pbkdf2, md5crypt and sha512crypt is supported too.
	Password string `json:"password,omitempty"`
	// PublicKeys used for public key authentication. At least one between password and a public key is mandatory
	PublicKeys []string `json:"public_keys,omitempty"`
	// The user cannot upload or download files outside this directory. Must be an absolute path
	HomeDir string `json:"home_dir"`
	// If sftpgo runs as root system user then the created files and directories will be assigned to this system UID
	UID int `json:"uid"`
	// If sftpgo runs as root system user then the created files and directories will be assigned to this system GID
	GID int `json:"gid"`
	// Maximum concurrent sessions. 0 means unlimited
	MaxSessions int `json:"max_sessions"`
	// Maximum size allowed as bytes. 0 means unlimited
	QuotaSize int64 `json:"quota_size"`
	// Maximum number of files allowed. 0 means unlimited
	QuotaFiles int `json:"quota_files"`
	// List of the granted permissions
	Permissions map[string][]string `json:"permissions"`
	// Used quota as bytes
	UsedQuotaSize int64 `json:"used_quota_size"`
	// Used quota as number of files
	UsedQuotaFiles int `json:"used_quota_files"`
	// Last quota update as unix timestamp in milliseconds
	LastQuotaUpdate int64 `json:"last_quota_update"`
	// Maximum upload bandwidth as KB/s, 0 means unlimited
	UploadBandwidth int64 `json:"upload_bandwidth"`
	// Maximum download bandwidth as KB/s, 0 means unlimited
	DownloadBandwidth int64 `json:"download_bandwidth"`
	// Last login as unix timestamp in milliseconds
	LastLogin int64 `json:"last_login"`
	// Additional restrictions
	Filters UserFilters `json:"filters"`
	// optional description, for example full name
	Description string `json:"description,omitempty"`
	// free form text field for external systems
	AdditionalInfo string `json:"additional_info,omitempty"`
}

// User defines a SFTPGo user
type User struct {
	BaseUser
	// Mapping between virtual paths and virtual folders
	VirtualFolders []VirtualFolder `json:"virtual_folders,omitempty"`
	// Filesystem configuration details
	FsConfig Filesystem `json:"filesystem"`
}