// ABOUTME: Configuration types for EdgeConnect apply command YAML parsing
// ABOUTME: Defines structs that match EdgeConnectConfig.yaml schema exactly
package config

import (
	"fmt"
	"os"
	"path/filepath"
	"strings"
)

// EdgeConnectConfig represents the top-level configuration structure
type EdgeConnectConfig struct {
	Kind     string   `yaml:"kind"`
	Metadata Metadata `yaml:"metadata"`
	Spec     Spec     `yaml:"spec"`
}

// Metadata contains configuration metadata
type Metadata struct {
	Name string `yaml:"name"`
}

// Spec defines the application and infrastructure specification
type Spec struct {
	K8sApp        *K8sApp         `yaml:"k8sApp,omitempty"`
	DockerApp     *DockerApp      `yaml:"dockerApp,omitempty"`
	InfraTemplate []InfraTemplate `yaml:"infraTemplate"`
	Network       *NetworkConfig  `yaml:"network,omitempty"`
}

// K8sApp defines Kubernetes application configuration
type K8sApp struct {
	AppName      string `yaml:"appName"`
	AppVersion   string `yaml:"appVersion"`
	ManifestFile string `yaml:"manifestFile"`
}

// DockerApp defines Docker application configuration
type DockerApp struct {
	AppName      string `yaml:"appName"`
	AppVersion   string `yaml:"appVersion"`
	ManifestFile string `yaml:"manifestFile"`
	Image        string `yaml:"image"`
}

// InfraTemplate defines infrastructure deployment targets
type InfraTemplate struct {
	Organization string `yaml:"organization"`
	Region       string `yaml:"region"`
	CloudletOrg  string `yaml:"cloudletOrg"`
	CloudletName string `yaml:"cloudletName"`
	FlavorName   string `yaml:"flavorName"`
}

// NetworkConfig defines network configuration
type NetworkConfig struct {
	OutboundConnections []OutboundConnection `yaml:"outboundConnections"`
}

// OutboundConnection defines an outbound network connection
type OutboundConnection struct {
	Protocol     string `yaml:"protocol"`
	PortRangeMin int    `yaml:"portRangeMin"`
	PortRangeMax int    `yaml:"portRangeMax"`
	RemoteCIDR   string `yaml:"remoteCIDR"`
}

// Validate performs comprehensive validation of the configuration
func (c *EdgeConnectConfig) Validate() error {
	if c.Kind == "" {
		return fmt.Errorf("kind is required")
	}

	if c.Kind != "edgeconnect-deployment" {
		return fmt.Errorf("unsupported kind: %s, expected 'edgeconnect-deployment'", c.Kind)
	}

	if err := c.Metadata.Validate(); err != nil {
		return fmt.Errorf("metadata validation failed: %w", err)
	}

	if err := c.Spec.Validate(); err != nil {
		return fmt.Errorf("spec validation failed: %w", err)
	}

	return nil
}

// Validate validates metadata fields
func (m *Metadata) Validate() error {
	if m.Name == "" {
		return fmt.Errorf("metadata.name is required")
	}

	if strings.TrimSpace(m.Name) != m.Name {
		return fmt.Errorf("metadata.name cannot have leading/trailing whitespace")
	}

	return nil
}

// Validate validates spec configuration
func (s *Spec) Validate() error {
	// Must have either k8sApp or dockerApp, but not both
	if s.K8sApp == nil && s.DockerApp == nil {
		return fmt.Errorf("spec must define either k8sApp or dockerApp")
	}

	if s.K8sApp != nil && s.DockerApp != nil {
		return fmt.Errorf("spec cannot define both k8sApp and dockerApp")
	}

	// Validate app configuration
	if s.K8sApp != nil {
		if err := s.K8sApp.Validate(); err != nil {
			return fmt.Errorf("k8sApp validation failed: %w", err)
		}
	}

	if s.DockerApp != nil {
		if err := s.DockerApp.Validate(); err != nil {
			return fmt.Errorf("dockerApp validation failed: %w", err)
		}
	}

	// Infrastructure template is required
	if len(s.InfraTemplate) == 0 {
		return fmt.Errorf("infraTemplate is required and must contain at least one target")
	}

	// Validate each infrastructure template
	for i, infra := range s.InfraTemplate {
		if err := infra.Validate(); err != nil {
			return fmt.Errorf("infraTemplate[%d] validation failed: %w", i, err)
		}
	}

	// Validate network configuration if present
	if s.Network != nil {
		if err := s.Network.Validate(); err != nil {
			return fmt.Errorf("network validation failed: %w", err)
		}
	}

	return nil
}

// Validate validates k8s app configuration
func (k *K8sApp) Validate() error {
	if k.AppName == "" {
		return fmt.Errorf("appName is required")
	}

	if k.AppVersion == "" {
		return fmt.Errorf("appVersion is required")
	}

	if k.ManifestFile == "" {
		return fmt.Errorf("manifestFile is required")
	}

	// Check if manifest file exists
	if _, err := os.Stat(k.ManifestFile); os.IsNotExist(err) {
		return fmt.Errorf("manifestFile does not exist: %s", k.ManifestFile)
	}

	// Validate app name format
	if strings.TrimSpace(k.AppName) != k.AppName {
		return fmt.Errorf("appName cannot have leading/trailing whitespace")
	}

	// Validate version format
	if strings.TrimSpace(k.AppVersion) != k.AppVersion {
		return fmt.Errorf("appVersion cannot have leading/trailing whitespace")
	}

	return nil
}

// Validate validates docker app configuration
func (d *DockerApp) Validate() error {
	if d.AppName == "" {
		return fmt.Errorf("appName is required")
	}

	if d.AppVersion == "" {
		return fmt.Errorf("appVersion is required")
	}

	if d.Image == "" {
		return fmt.Errorf("image is required")
	}

	// Validate app name format
	if strings.TrimSpace(d.AppName) != d.AppName {
		return fmt.Errorf("appName cannot have leading/trailing whitespace")
	}

	// Validate version format
	if strings.TrimSpace(d.AppVersion) != d.AppVersion {
		return fmt.Errorf("appVersion cannot have leading/trailing whitespace")
	}

	// Check if manifest file exists if specified
	if d.ManifestFile != "" {
		if _, err := os.Stat(d.ManifestFile); os.IsNotExist(err) {
			return fmt.Errorf("manifestFile does not exist: %s", d.ManifestFile)
		}
	}

	return nil
}

// Validate validates infrastructure template configuration
func (i *InfraTemplate) Validate() error {
	if i.Organization == "" {
		return fmt.Errorf("organization is required")
	}

	if i.Region == "" {
		return fmt.Errorf("region is required")
	}

	if i.CloudletOrg == "" {
		return fmt.Errorf("cloudletOrg is required")
	}

	if i.CloudletName == "" {
		return fmt.Errorf("cloudletName is required")
	}

	if i.FlavorName == "" {
		return fmt.Errorf("flavorName is required")
	}

	// Validate no leading/trailing whitespace
	fields := map[string]string{
		"organization": i.Organization,
		"region":       i.Region,
		"cloudletOrg":  i.CloudletOrg,
		"cloudletName": i.CloudletName,
		"flavorName":   i.FlavorName,
	}

	for field, value := range fields {
		if strings.TrimSpace(value) != value {
			return fmt.Errorf("%s cannot have leading/trailing whitespace", field)
		}
	}

	return nil
}

// Validate validates network configuration
func (n *NetworkConfig) Validate() error {
	if len(n.OutboundConnections) == 0 {
		return fmt.Errorf("outboundConnections is required when network is specified")
	}

	for i, conn := range n.OutboundConnections {
		if err := conn.Validate(); err != nil {
			return fmt.Errorf("outboundConnections[%d] validation failed: %w", i, err)
		}
	}

	return nil
}

// Validate validates outbound connection configuration
func (o *OutboundConnection) Validate() error {
	if o.Protocol == "" {
		return fmt.Errorf("protocol is required")
	}

	validProtocols := map[string]bool{
		"tcp":  true,
		"udp":  true,
		"icmp": true,
	}

	if !validProtocols[strings.ToLower(o.Protocol)] {
		return fmt.Errorf("protocol must be one of: tcp, udp, icmp")
	}

	if o.PortRangeMin <= 0 || o.PortRangeMin > 65535 {
		return fmt.Errorf("portRangeMin must be between 1 and 65535")
	}

	if o.PortRangeMax <= 0 || o.PortRangeMax > 65535 {
		return fmt.Errorf("portRangeMax must be between 1 and 65535")
	}

	if o.PortRangeMin > o.PortRangeMax {
		return fmt.Errorf("portRangeMin (%d) cannot be greater than portRangeMax (%d)", o.PortRangeMin, o.PortRangeMax)
	}

	if o.RemoteCIDR == "" {
		return fmt.Errorf("remoteCIDR is required")
	}

	return nil
}

// GetManifestPath returns the absolute path to the manifest file
func (k *K8sApp) GetManifestPath(configDir string) string {
	if filepath.IsAbs(k.ManifestFile) {
		return k.ManifestFile
	}
	return filepath.Join(configDir, k.ManifestFile)
}

// GetManifestPath returns the absolute path to the manifest file
func (d *DockerApp) GetManifestPath(configDir string) string {
	if d.ManifestFile == "" {
		return ""
	}
	if filepath.IsAbs(d.ManifestFile) {
		return d.ManifestFile
	}
	return filepath.Join(configDir, d.ManifestFile)
}

// GetAppName returns the application name from the active app type
func (s *Spec) GetAppName() string {
	if s.K8sApp != nil {
		return s.K8sApp.AppName
	}
	if s.DockerApp != nil {
		return s.DockerApp.AppName
	}
	return ""
}

// GetAppVersion returns the application version from the active app type
func (s *Spec) GetAppVersion() string {
	if s.K8sApp != nil {
		return s.K8sApp.AppVersion
	}
	if s.DockerApp != nil {
		return s.DockerApp.AppVersion
	}
	return ""
}

// GetManifestFile returns the manifest file path from the active app type
func (s *Spec) GetManifestFile() string {
	if s.K8sApp != nil {
		return s.K8sApp.ManifestFile
	}
	if s.DockerApp != nil {
		return s.DockerApp.ManifestFile
	}
	return ""
}

// IsK8sApp returns true if this is a Kubernetes application
func (s *Spec) IsK8sApp() bool {
	return s.K8sApp != nil
}

// IsDockerApp returns true if this is a Docker application
func (s *Spec) IsDockerApp() bool {
	return s.DockerApp != nil
}