package ldap

import (
	"context"
	"time"

	"github.com/zitadel/zitadel/internal/idp"
)

const DefaultPort = "389"

var _ idp.Provider = (*Provider)(nil)

// Provider is the [idp.Provider] implementation for a generic LDAP provider
type Provider struct {
	name              string
	servers           []string
	startTLS          bool
	baseDN            string
	bindDN            string
	bindPassword      string
	userBase          string
	userObjectClasses []string
	userFilters       []string
	timeout           time.Duration

	loginUrl string

	isLinkingAllowed  bool
	isCreationAllowed bool
	isAutoCreation    bool
	isAutoUpdate      bool

	idAttribute                string
	firstNameAttribute         string
	lastNameAttribute          string
	displayNameAttribute       string
	nickNameAttribute          string
	preferredUsernameAttribute string
	emailAttribute             string
	emailVerifiedAttribute     string
	phoneAttribute             string
	phoneVerifiedAttribute     string
	preferredLanguageAttribute string
	avatarURLAttribute         string
	profileAttribute           string
}

type ProviderOpts func(provider *Provider)

// WithLinkingAllowed allows end users to link the federated user to an existing one.
func WithLinkingAllowed() ProviderOpts {
	return func(p *Provider) {
		p.isLinkingAllowed = true
	}
}

// WithCreationAllowed allows end users to create a new user using the federated information.
func WithCreationAllowed() ProviderOpts {
	return func(p *Provider) {
		p.isCreationAllowed = true
	}
}

// WithAutoCreation enables that federated users are automatically created if not already existing.
func WithAutoCreation() ProviderOpts {
	return func(p *Provider) {
		p.isAutoCreation = true
	}
}

// WithAutoUpdate enables that information retrieved from the provider is automatically used to update
// the existing user on each authentication.
func WithAutoUpdate() ProviderOpts {
	return func(p *Provider) {
		p.isAutoUpdate = true
	}
}

// WithoutStartTLS configures to communication insecure with the LDAP server without startTLS
func WithoutStartTLS() ProviderOpts {
	return func(p *Provider) {
		p.startTLS = false
	}
}

// WithCustomIDAttribute configures to map the LDAP attribute to the user, default is the uniqueUserAttribute
func WithCustomIDAttribute(name string) ProviderOpts {
	return func(p *Provider) {
		p.idAttribute = name
	}
}

// WithFirstNameAttribute configures to map the LDAP attribute to the user
func WithFirstNameAttribute(name string) ProviderOpts {
	return func(p *Provider) {
		p.firstNameAttribute = name
	}
}

// WithLastNameAttribute configures to map the LDAP attribute to the user
func WithLastNameAttribute(name string) ProviderOpts {
	return func(p *Provider) {
		p.lastNameAttribute = name
	}
}

// WithDisplayNameAttribute configures to map the LDAP attribute to the user
func WithDisplayNameAttribute(name string) ProviderOpts {
	return func(p *Provider) {
		p.displayNameAttribute = name
	}
}

// WithNickNameAttribute configures to map the LDAP attribute to the user
func WithNickNameAttribute(name string) ProviderOpts {
	return func(p *Provider) {
		p.nickNameAttribute = name
	}
}

// WithPreferredUsernameAttribute configures to map the LDAP attribute to the user
func WithPreferredUsernameAttribute(name string) ProviderOpts {
	return func(p *Provider) {
		p.preferredUsernameAttribute = name
	}
}

// WithEmailAttribute configures to map the LDAP attribute to the user
func WithEmailAttribute(name string) ProviderOpts {
	return func(p *Provider) {
		p.emailAttribute = name
	}
}

// WithEmailVerifiedAttribute configures to map the LDAP attribute to the user
func WithEmailVerifiedAttribute(name string) ProviderOpts {
	return func(p *Provider) {
		p.emailVerifiedAttribute = name
	}
}

// WithPhoneAttribute configures to map the LDAP attribute to the user
func WithPhoneAttribute(name string) ProviderOpts {
	return func(p *Provider) {
		p.phoneAttribute = name
	}
}

// WithPhoneVerifiedAttribute configures to map the LDAP attribute to the user
func WithPhoneVerifiedAttribute(name string) ProviderOpts {
	return func(p *Provider) {
		p.phoneVerifiedAttribute = name
	}
}

// WithPreferredLanguageAttribute configures to map the LDAP attribute to the user
func WithPreferredLanguageAttribute(name string) ProviderOpts {
	return func(p *Provider) {
		p.preferredLanguageAttribute = name
	}
}

// WithAvatarURLAttribute configures to map the LDAP attribute to the user
func WithAvatarURLAttribute(name string) ProviderOpts {
	return func(p *Provider) {
		p.avatarURLAttribute = name
	}
}

// WithProfileAttribute configures to map the LDAP attribute to the user
func WithProfileAttribute(name string) ProviderOpts {
	return func(p *Provider) {
		p.profileAttribute = name
	}
}

func New(
	name string,
	servers []string,
	baseDN string,
	bindDN string,
	bindPassword string,
	userBase string,
	userObjectClasses []string,
	userFilters []string,
	timeout time.Duration,
	loginUrl string,
	options ...ProviderOpts,
) *Provider {
	provider := &Provider{
		name:              name,
		servers:           servers,
		startTLS:          true,
		baseDN:            baseDN,
		bindDN:            bindDN,
		bindPassword:      bindPassword,
		userBase:          userBase,
		userObjectClasses: userObjectClasses,
		userFilters:       userFilters,
		timeout:           timeout,
		loginUrl:          loginUrl,
	}
	for _, option := range options {
		option(provider)
	}
	return provider
}

func (p *Provider) Name() string {
	return p.name
}

func (p *Provider) BeginAuth(ctx context.Context, state string, params ...any) (idp.Session, error) {
	return &Session{
		Provider: p,
		loginUrl: p.loginUrl + state,
	}, nil
}

func (p *Provider) IsLinkingAllowed() bool {
	return p.isLinkingAllowed
}

func (p *Provider) IsCreationAllowed() bool {
	return p.isCreationAllowed
}

func (p *Provider) IsAutoCreation() bool {
	return p.isAutoCreation
}

func (p *Provider) IsAutoUpdate() bool {
	return p.isAutoUpdate
}

func (p *Provider) getNecessaryAttributes() []string {
	attributes := []string{p.userBase}
	if p.idAttribute != "" {
		attributes = append(attributes, p.idAttribute)
	}
	if p.firstNameAttribute != "" {
		attributes = append(attributes, p.firstNameAttribute)
	}
	if p.lastNameAttribute != "" {
		attributes = append(attributes, p.lastNameAttribute)
	}
	if p.displayNameAttribute != "" {
		attributes = append(attributes, p.displayNameAttribute)
	}
	if p.nickNameAttribute != "" {
		attributes = append(attributes, p.nickNameAttribute)
	}
	if p.preferredUsernameAttribute != "" {
		attributes = append(attributes, p.preferredUsernameAttribute)
	}
	if p.emailAttribute != "" {
		attributes = append(attributes, p.emailAttribute)
	}
	if p.emailVerifiedAttribute != "" {
		attributes = append(attributes, p.emailVerifiedAttribute)
	}
	if p.phoneAttribute != "" {
		attributes = append(attributes, p.phoneAttribute)
	}
	if p.phoneVerifiedAttribute != "" {
		attributes = append(attributes, p.phoneVerifiedAttribute)
	}
	if p.preferredLanguageAttribute != "" {
		attributes = append(attributes, p.preferredLanguageAttribute)
	}
	if p.avatarURLAttribute != "" {
		attributes = append(attributes, p.avatarURLAttribute)
	}
	if p.profileAttribute != "" {
		attributes = append(attributes, p.profileAttribute)
	}
	return attributes
}