package iis

import (
	"context"
	"encoding/json"
	"fmt"
	"log/slog"
	"runtime"
	"time"

	"github.com/shankar0123/certctl/internal/connector/target"
)

// Config represents the IIS deployment target configuration.
// This configuration is for Windows agents that manage IIS servers.
type Config struct {
	Hostname    string `json:"hostname"`     // Target hostname or IP
	SiteName    string `json:"site_name"`    // IIS site name (e.g., "Default Web Site")
	CertStore   string `json:"cert_store"`   // Windows cert store (e.g., "My", "WebHosting")
	BindingInfo string `json:"binding_info"` // Binding info (e.g., "*.example.com")
}

// Connector implements the target.Connector interface for IIS (Internet Information Services).
// This connector runs on Windows agents and manages certificate deployment via IIS.
//
// IIS certificate management requires:
// - Windows Server with IIS installed
// - PowerShell execution available
// - Administrative privileges
//
// TODO: Implement actual PowerShell command execution for:
// - Certificate import: Import-PfxCertificate
// - IIS binding update: New-WebBinding, Set-WebBinding
// - Validation: Get-WebBinding
type Connector struct {
	config *Config
	logger *slog.Logger
}

// New creates a new IIS target connector with the given configuration and logger.
func New(config *Config, logger *slog.Logger) *Connector {
	return &Connector{
		config: config,
		logger: logger,
	}
}

// ValidateConfig checks that the IIS configuration is valid and accessible.
// It verifies that we're on Windows and that the IIS site exists.
//
// TODO: Implement actual PowerShell checks.
func (c *Connector) ValidateConfig(ctx context.Context, rawConfig json.RawMessage) error {
	var cfg Config
	if err := json.Unmarshal(rawConfig, &cfg); err != nil {
		return fmt.Errorf("invalid IIS config: %w", err)
	}

	if cfg.SiteName == "" || cfg.CertStore == "" {
		return fmt.Errorf("IIS site_name and cert_store are required")
	}

	// Verify we're on Windows
	if runtime.GOOS != "windows" {
		return fmt.Errorf("IIS connector only runs on Windows, got %s", runtime.GOOS)
	}

	c.logger.Info("validating IIS configuration",
		"site_name", cfg.SiteName,
		"cert_store", cfg.CertStore,
		"hostname", cfg.Hostname)

	// TODO: Implement PowerShell check
	// In production:
	//   1. Run PowerShell command: Get-IISSite -Name {SiteName}
	//   2. Verify site exists and is running
	//   3. Check cert store: Get-Item -Path "Cert:\LocalMachine\{CertStore}"

	c.logger.Warn("IIS validation not yet fully implemented",
		"site_name", cfg.SiteName)

	c.config = &cfg
	return nil
}

// DeployCertificate imports a certificate to the Windows certificate store and updates
// the IIS binding to use the new certificate.
//
// The IIS deployment process (via PowerShell):
//  1. Create a temporary PFX file from the certificate and existing private key
//     (Note: The private key is managed by the agent, not provided by the control plane)
//  2. Import the PFX to the Windows certificate store (My store by default)
//  3. Get the certificate thumbprint
//  4. Update the IIS binding to use the new certificate by thumbprint
//  5. Verify the binding is active
//
// TODO: Implement actual PowerShell commands:
// - Import-PfxCertificate -FilePath {pfxPath} -CertStoreLocation "Cert:\LocalMachine\My"
// - Get-ChildItem -Path "Cert:\LocalMachine\My" | Where {$_.Subject -eq "CN=..."}
// - Set-WebBinding -Name {SiteName} -BindingInformation "{BindingInfo}" -Protocol https -SslFlags 1 -CertificateThumbprint {thumbprint}
func (c *Connector) DeployCertificate(ctx context.Context, request target.DeploymentRequest) (*target.DeploymentResult, error) {
	c.logger.Info("deploying certificate to IIS",
		"site_name", c.config.SiteName,
		"cert_store", c.config.CertStore)

	startTime := time.Now()

	// TODO: Implement IIS certificate deployment
	// In production:
	//   1. Create temporary PFX from CertPEM and ChainPEM
	//      (Private key should already exist on the agent)
	//   2. Import certificate:
	//      PowerShell: Import-PfxCertificate -FilePath $pfxPath -CertStoreLocation "Cert:\LocalMachine\{CertStore}" -Password $password
	//   3. Get certificate thumbprint:
	//      PowerShell: (Get-ChildItem -Path "Cert:\LocalMachine\{CertStore}" | Where {$_.Subject -like "*CN=*"}).Thumbprint
	//   4. Update IIS binding:
	//      PowerShell: Set-WebBinding -Name "{SiteName}" -BindingInformation "{BindingInfo}:443:*.example.com" -Protocol https -CertificateThumbprint $thumbprint
	//   5. Remove temporary PFX file

	deploymentDuration := time.Since(startTime)

	c.logger.Warn("IIS deployment not yet implemented",
		"site_name", c.config.SiteName)

	return &target.DeploymentResult{
		Success:       true,
		TargetAddress: fmt.Sprintf("%s (IIS: %s)", c.config.Hostname, c.config.SiteName),
		DeploymentID:  fmt.Sprintf("iis-%d", time.Now().Unix()),
		Message:       "Certificate deployment to IIS initiated (stub)",
		DeployedAt:    time.Now(),
		Metadata: map[string]string{
			"hostname":    c.config.Hostname,
			"site_name":   c.config.SiteName,
			"cert_store":  c.config.CertStore,
			"duration_ms": fmt.Sprintf("%d", deploymentDuration.Milliseconds()),
		},
	}, nil
}

// ValidateDeployment verifies that the certificate is properly deployed in IIS.
// It checks the IIS binding configuration to ensure it's active with the correct certificate.
//
// TODO: Implement actual PowerShell validation.
// PowerShell command:
// - Get-IISSiteBinding -Name {SiteName} | Where {$_.protocol -eq "https"}
func (c *Connector) ValidateDeployment(ctx context.Context, request target.ValidationRequest) (*target.ValidationResult, error) {
	c.logger.Info("validating IIS deployment",
		"certificate_id", request.CertificateID,
		"serial", request.Serial,
		"site_name", c.config.SiteName)

	startTime := time.Now()

	// TODO: Implement IIS deployment validation
	// In production:
	//   1. Query IIS binding status:
	//      PowerShell: Get-WebBinding -Name "{SiteName}" -Protocol "https"
	//   2. Verify binding exists and is active
	//   3. Extract certificate thumbprint from binding
	//   4. Query certificate store to verify thumbprint matches expected certificate
	//   5. Check certificate validity dates and key match

	validationDuration := time.Since(startTime)

	c.logger.Warn("IIS validation not yet implemented",
		"site_name", c.config.SiteName)

	return &target.ValidationResult{
		Valid:         true,
		Serial:        request.Serial,
		TargetAddress: fmt.Sprintf("%s (IIS: %s)", c.config.Hostname, c.config.SiteName),
		Message:       "Certificate deployment validation initiated (stub)",
		ValidatedAt:   time.Now(),
		Metadata: map[string]string{
			"hostname":    c.config.Hostname,
			"site_name":   c.config.SiteName,
			"duration_ms": fmt.Sprintf("%d", validationDuration.Milliseconds()),
		},
	}, nil
}

// executePowerShellCommand will be implemented in V3 when IIS target connector ships.
// Pattern: exec.CommandContext(ctx, "powershell", "-NoProfile", "-Command", psCommand)