package config

import (
	"errors"
	"fmt"
	"net/netip"
	"net/url"

	"github.com/netbirdio/netbird/management/server/idp"
	"github.com/netbirdio/netbird/management/server/types"
	"github.com/netbirdio/netbird/shared/management/client/common"
	"github.com/netbirdio/netbird/util"
)

type (
	// Protocol type
	Protocol string

	// Provider authorization flow type
	Provider string
)

const (
	UDP   Protocol = "udp"
	DTLS  Protocol = "dtls"
	TCP   Protocol = "tcp"
	HTTP  Protocol = "http"
	HTTPS Protocol = "https"
	NONE  Provider = "none"
)

const (
	// DefaultDeviceAuthFlowScope defines the bare minimum scope to request in the device authorization flow
	DefaultDeviceAuthFlowScope string = "openid"
)

var MgmtConfigPath string

// Config of the Management service
type Config struct {
	Stuns      []*Host
	TURNConfig *TURNConfig
	Relay      *Relay
	Signal     *Host

	Datadir                string
	DataStoreEncryptionKey string

	HttpConfig *HttpServerConfig

	IdpManagerConfig *idp.Config

	DeviceAuthorizationFlow *DeviceAuthorizationFlow

	PKCEAuthorizationFlow *PKCEAuthorizationFlow

	StoreConfig StoreConfig

	ReverseProxy ReverseProxy

	AgentNetwork AgentNetwork

	// DebugUpload configures where the peers of this deployment send their
	// debug bundles. See DebugUpload.
	DebugUpload DebugUpload

	// disable default all-to-all policy
	DisableDefaultPolicy bool

	// EmbeddedIdP contains configuration for the embedded Dex OIDC provider.
	// When set, Dex will be embedded in the management server and serve requests at /oauth2/
	EmbeddedIdP *idp.EmbeddedIdPConfig

	HighestSupportedSyncMessageVersion *int

	PerAccountHighestSupportedSyncMessageVersion map[string]int
}

// GetAuthAudiences returns the audience from the http config and device authorization flow config
func (c Config) GetAuthAudiences() []string {
	audiences := []string{c.HttpConfig.AuthAudience}

	if c.HttpConfig.ExtraAuthAudience != "" {
		audiences = append(audiences, c.HttpConfig.ExtraAuthAudience)
	}

	if c.DeviceAuthorizationFlow != nil && c.DeviceAuthorizationFlow.ProviderConfig.Audience != "" {
		audiences = append(audiences, c.DeviceAuthorizationFlow.ProviderConfig.Audience)
	}

	return audiences
}

// TURNConfig is a config of the TURNCredentialsManager
type TURNConfig struct {
	TimeBasedCredentials bool
	CredentialsTTL       util.Duration
	Secret               string
	Turns                []*Host
}

// Relay configuration type
type Relay struct {
	Addresses      []string
	CredentialsTTL util.Duration
	Secret         string
}

// HttpServerConfig is a config of the HTTP Management service server
type HttpServerConfig struct {
	LetsEncryptDomain string
	// CertFile is the location of the certificate
	CertFile string
	// CertKey is the location of the certificate private key
	CertKey string
	// AuthClientID is the client id used for proxy SSO auth
	AuthClientID string
	// AuthAudience identifies the recipients that the JWT is intended for (aud in JWT)
	AuthAudience string
	// CLIAuthAudience identifies the client app recipients that the JWT is intended for (aud in JWT)
	// Used only in conjunction with EmbeddedIdP
	CLIAuthAudience string
	// AuthIssuer identifies principal that issued the JWT
	AuthIssuer string
	// AuthUserIDClaim is the name of the claim that used as user ID
	AuthUserIDClaim string
	// AuthKeysLocation is a location of JWT key set containing the public keys used to verify JWT
	AuthKeysLocation string
	// OIDCConfigEndpoint is the endpoint of an IDP manager to get OIDC configuration
	OIDCConfigEndpoint string
	// IdpSignKeyRefreshEnabled identifies the signing key is currently being rotated or not
	IdpSignKeyRefreshEnabled bool
	// Extra audience
	ExtraAuthAudience string
	// AuthCallbackDomain contains the callback domain
	AuthCallbackURL string
}

// Host represents a Netbird host (e.g. STUN, TURN, Signal)
type Host struct {
	Proto Protocol
	// URI e.g. turns://stun.netbird.io:4430 or signal.netbird.io:10000
	URI      string
	Username string
	Password string
}

// DeviceAuthorizationFlow represents Device Authorization Flow information
// that can be used by the client to login initiate a Oauth 2.0 device authorization grant flow
// see https://datatracker.ietf.org/doc/html/rfc8628
type DeviceAuthorizationFlow struct {
	Provider       string
	ProviderConfig ProviderConfig
}

// PKCEAuthorizationFlow represents Authorization Code Flow information
// that can be used by the client to login initiate a Oauth 2.0 authorization code grant flow
// with Proof Key for Code Exchange (PKCE). See https://datatracker.ietf.org/doc/html/rfc7636
type PKCEAuthorizationFlow struct {
	ProviderConfig ProviderConfig
}

// ProviderConfig has all attributes needed to initiate a device/pkce authorization flow
type ProviderConfig struct {
	// ClientID An IDP application client id
	ClientID string
	// ClientSecret An IDP application client secret
	ClientSecret string
	// Domain An IDP API domain
	// Deprecated. Use TokenEndpoint and DeviceAuthEndpoint
	Domain string
	// Audience An Audience for to authorization validation
	Audience string
	// TokenEndpoint is the endpoint of an IDP manager where clients can obtain access token
	TokenEndpoint string
	// DeviceAuthEndpoint is the endpoint of an IDP manager where clients can obtain device authorization code
	DeviceAuthEndpoint string
	// AuthorizationEndpoint is the endpoint of an IDP manager where clients can obtain authorization code
	AuthorizationEndpoint string
	// Scopes provides the scopes to be included in the token request
	Scope string
	// UseIDToken indicates if the id token should be used for authentication
	UseIDToken bool
	// RedirectURL handles authorization code from IDP manager
	RedirectURLs []string
	// DisablePromptLogin makes the PKCE flow to not prompt the user for login
	DisablePromptLogin bool
	// LoginFlag is used to configure the PKCE flow login behavior
	LoginFlag common.LoginFlag
}

// StoreConfig contains Store configuration
type StoreConfig struct {
	Engine types.Engine
}

// AgentNetwork contains agent-network (LLM gateway) configuration.
type AgentNetwork struct {
	// PricingDefaultsFile is the path to the YAML file holding the default
	// LLM pricing table (defaults_llm_pricing.yaml). A relative path is
	// resolved against <Datadir>, so a bare filename lands alongside the
	// store. Empty falls back to probing <Datadir>/defaults_llm_pricing.yaml;
	// with no file present the compiled-in defaults serve. Schema: surface ("openai"/"anthropic"/
	// "bedrock") -> model -> rates in USD per 1k tokens (input_per_1k,
	// output_per_1k, and the optional cached_input_per_1k /
	// cache_read_per_1k / cache_creation_per_1k). File entries replace the
	// compiled-in entry for the same surface+model whole; everything else
	// keeps the compiled-in rates. The file is re-read periodically (mtime
	// poll), and the live table feeds both the synthesizer (what proxies
	// bill with) and the dashboard's catalog endpoint (what model rows
	// prefill with). An explicitly configured path that fails to load
	// fails startup; runtime reload errors keep the previous table.
	PricingDefaultsFile string
}

// DebugUpload configures the debug-bundle upload service this deployment
// publishes to its peers.
//
// The client paths that upload without a human picking a destination — the
// remote debug-bundle job, the mobile clients and the desktop UI — take the
// destination from here. It exists so an operator who needs the bundles, which
// carry peer logs, routes, DNS and firewall state, to stay inside their own
// infrastructure can say so once. Leaving it unset publishes no destination and
// the peers upload to the service NetBird runs, which keeps the everyday
// "collect a bundle and send it to support" flow working out of the box.
//
// Set URL to the upload service's get-URL endpoint, e.g.
// https://upload.example.com/upload-url (see the upload-server component).
type DebugUpload struct {
	// URL is the get-URL endpoint of the upload service. Must be https: the
	// client fetches an upload URL from it and then PUTs the bundle to whatever
	// that fetch returns, so a plaintext hop is a place to intercept both.
	URL string
}

// Validate rejects a destination the client would refuse anyway, so a typo in
// management.json surfaces at startup instead of at the first bundle upload.
func (d DebugUpload) Validate() error {
	if d.URL == "" {
		return nil
	}

	parsed, err := url.Parse(d.URL)
	if err != nil {
		return fmt.Errorf("parse debug upload URL: %w", err)
	}
	if parsed.Scheme != "https" {
		return fmt.Errorf("debug upload URL must use https, got scheme %q", parsed.Scheme)
	}
	// Hostname(), not Host: an authority like ":443" is non-empty but has no
	// host, and the peers reject it (see profilemanager.ValidateBundleUploadURL).
	// Management must not publish a destination its own clients refuse.
	if parsed.Hostname() == "" {
		return errors.New("debug upload URL must have a host")
	}

	return nil
}

// ReverseProxy contains reverse proxy configuration in front of management.
type ReverseProxy struct {
	// TrustedHTTPProxies represents a list of trusted HTTP proxies by their IP prefixes.
	// When extracting the real IP address from request headers, the middleware will verify
	// if the peer's address falls within one of these trusted IP prefixes.
	TrustedHTTPProxies []netip.Prefix

	// TrustedHTTPProxiesCount specifies the count of trusted HTTP proxies between the internet
	// and the server. When using the trusted proxy count method to extract the real IP address,
	// the middleware will search the X-Forwarded-For IP list from the rightmost by this count
	// minus one.
	TrustedHTTPProxiesCount uint

	// TrustedPeers represents a list of trusted peers by their IP prefixes.
	// These peers are considered trustworthy by the gRPC server operator,
	// and the middleware will attempt to extract the real IP address from
	// request headers if the peer's address falls within one of these
	// trusted IP prefixes.
	TrustedPeers []netip.Prefix

	// AccessLogRetentionDays specifies the number of days to retain access logs.
	// Logs older than this duration will be automatically deleted during cleanup.
	// A value of 0 will default to 7 days. Negative means logs are kept indefinitely (no cleanup).
	AccessLogRetentionDays int

	// AccessLogCleanupIntervalHours specifies how often (in hours) to run the cleanup routine.
	// Defaults to 24 hours if not set or set to 0.
	AccessLogCleanupIntervalHours int
}