package config

import (
	"os"
	"regexp"
	"strconv"
	"time"

	"github.com/michaelquigley/df/dd"
	"github.com/openziti/zrok/v2/controller/agentController"
	"github.com/openziti/zrok/v2/controller/automation"
	"github.com/openziti/zrok/v2/controller/dynamicProxyController"
	"github.com/openziti/zrok/v2/controller/emailUi"
	"github.com/openziti/zrok/v2/controller/env"
	"github.com/openziti/zrok/v2/controller/limits"
	"github.com/openziti/zrok/v2/controller/metrics"
	"github.com/openziti/zrok/v2/controller/store"
	"github.com/pkg/errors"
)

const ConfigVersion = 4

type Config struct {
	V                      int
	Admin                  *AdminConfig
	AgentController        *agentController.Config
	Bridge                 *metrics.BridgeConfig
	Compatibility          *CompatibilityConfig
	DynamicProxyController *dynamicProxyController.Config
	Endpoint               *EndpointConfig
	Email                  *emailUi.Config
	Invites                *InvitesConfig
	Limits                 *limits.Config
	Maintenance            *MaintenanceConfig
	Metrics                *metrics.Config
	Names                  *NamesConfig
	Registration           *RegistrationConfig
	ResetPassword          *ResetPasswordConfig
	Store                  *store.Config
	Ziti                   *automation.Config
	Tls                    *TlsConfig
}

type AdminConfig struct {
	Secrets         []string `dd:"+secret"`
	TouLink         string
	NewAccountLink  string
	ProfileEndpoint string
}

type EndpointConfig struct {
	Host string
	Port int
}

type InvitesConfig struct {
	InvitesOpen   bool
	TokenStrategy string
	TokenContact  string
}

type MaintenanceConfig struct {
	ResetPassword *ResetPasswordMaintenanceConfig
	Registration  *RegistrationMaintenanceConfig
}

type RegistrationConfig struct {
	RegistrationUrlTemplate string
}

type ResetPasswordConfig struct {
	ResetUrlTemplate string
}

type RegistrationMaintenanceConfig struct {
	ExpirationTimeout time.Duration
	CheckFrequency    time.Duration
	BatchLimit        int
}

type ResetPasswordMaintenanceConfig struct {
	ExpirationTimeout time.Duration
	CheckFrequency    time.Duration
	BatchLimit        int
}

type NamesConfig struct {
	DisableShareTokenProfanityCheck   bool
	DisableNamespaceNameProfanityCheck bool
}

type TlsConfig struct {
	CertPath string
	KeyPath  string
}

type CompatibilityConfig struct {
	LogRequests      bool
	VersionPatterns  []string
	compiledPatterns []*regexp.Regexp
}

func DefaultConfig() *Config {
	cfg := &Config{
		Compatibility: &CompatibilityConfig{
			VersionPatterns: []string{
				`^(refs/(heads|tags)/)?v2\.0`,
			},
		},
		Limits: limits.DefaultConfig(),
		Maintenance: &MaintenanceConfig{
			ResetPassword: &ResetPasswordMaintenanceConfig{
				ExpirationTimeout: time.Minute * 15,
				CheckFrequency:    time.Minute * 15,
				BatchLimit:        500,
			},
			Registration: &RegistrationMaintenanceConfig{
				ExpirationTimeout: time.Hour * 24,
				CheckFrequency:    time.Hour,
				BatchLimit:        500,
			},
		},
	}
	// compile default patterns
	if err := cfg.compileCompatibilityPatterns(); err != nil {
		panic(errors.Wrap(err, "error compiling default compatibility patterns"))
	}
	return cfg
}

func LoadConfig(path string) (*Config, error) {
	cfg := DefaultConfig()
	if err := dd.MergeFromYAML(cfg, path, env.GetDdOptions()); err != nil {
		return nil, errors.Wrapf(err, "error loading controller config '%v'", path)
	}
	if !envVersionOk() && cfg.V != ConfigVersion {
		return nil, errors.Errorf("expecting configuration version '%v', your configuration is version '%v'; please see zrok.io for changelog and configuration documentation", ConfigVersion, cfg.V)
	}
	if err := cfg.compileCompatibilityPatterns(); err != nil {
		return nil, errors.Wrap(err, "error compiling compatibility patterns")
	}
	return cfg, nil
}

func (cfg *Config) compileCompatibilityPatterns() error {
	if cfg.Compatibility == nil {
		return nil
	}

	compiled := make([]*regexp.Regexp, len(cfg.Compatibility.VersionPatterns))
	for i, pattern := range cfg.Compatibility.VersionPatterns {
		re, err := regexp.Compile(pattern)
		if err != nil {
			return errors.Wrapf(err, "invalid regex pattern '%v' at index %d", pattern, i)
		}
		compiled[i] = re
	}
	cfg.Compatibility.compiledPatterns = compiled
	return nil
}

func (cfg *CompatibilityConfig) GetCompiledPatterns() []*regexp.Regexp {
	return cfg.compiledPatterns
}

func envVersionOk() bool {
	vStr := os.Getenv("ZROK2_CTRL_CONFIG_VERSION")
	if vStr != "" {
		envV, err := strconv.Atoi(vStr)
		if err != nil {
			return false
		}
		if envV == ConfigVersion {
			return true
		}
	}
	return false
}