/*
Copyright (c) Edgeless Systems GmbH

SPDX-License-Identifier: AGPL-3.0-only
*/

package config

import (
	"bytes"
	"context"
	"fmt"

	"github.com/edgelesssys/constellation/v2/internal/api/configapi"
	"github.com/edgelesssys/constellation/v2/internal/api/fetcher"
	"github.com/edgelesssys/constellation/v2/internal/attestation/idkeydigest"
	"github.com/edgelesssys/constellation/v2/internal/attestation/measurements"
	"github.com/edgelesssys/constellation/v2/internal/cloud/cloudprovider"
	"github.com/edgelesssys/constellation/v2/internal/variant"
)

// AzureSEVSNP is the configuration for Azure SEV-SNP attestation.
type AzureSEVSNP struct {
	// description: |
	//   Expected TPM measurements.
	Measurements measurements.M `json:"measurements" yaml:"measurements" validate:"required,no_placeholders"`
	// description: |
	//   Lowest acceptable bootloader version.
	BootloaderVersion configapi.AttestationVersion `json:"bootloaderVersion" yaml:"bootloaderVersion"`
	// description: |
	//   Lowest acceptable TEE version.
	TEEVersion configapi.AttestationVersion `json:"teeVersion" yaml:"teeVersion"`
	// description: |
	//   Lowest acceptable SEV-SNP version.
	SNPVersion configapi.AttestationVersion `json:"snpVersion" yaml:"snpVersion"`
	// description: |
	//   Lowest acceptable microcode version.
	MicrocodeVersion configapi.AttestationVersion `json:"microcodeVersion" yaml:"microcodeVersion"`
	// description: |
	//   Configuration for validating the firmware signature.
	FirmwareSignerConfig SNPFirmwareSignerConfig `json:"firmwareSignerConfig" yaml:"firmwareSignerConfig"`
	// description: |
	//   AMD Root Key certificate used to verify the SEV-SNP certificate chain.
	AMDRootKey Certificate `json:"amdRootKey" yaml:"amdRootKey"`
}

// DefaultForAzureSEVSNP returns the default configuration for Azure SEV-SNP attestation.
// Version numbers have placeholder values and the latest available values can be fetched using [AzureSEVSNP.FetchAndSetLatestVersionNumbers].
func DefaultForAzureSEVSNP() *AzureSEVSNP {
	return &AzureSEVSNP{
		Measurements:      measurements.DefaultsFor(cloudprovider.Azure, variant.AzureSEVSNP{}),
		BootloaderVersion: configapi.NewLatestPlaceholderVersion(),
		TEEVersion:        configapi.NewLatestPlaceholderVersion(),
		SNPVersion:        configapi.NewLatestPlaceholderVersion(),
		MicrocodeVersion:  configapi.NewLatestPlaceholderVersion(),
		FirmwareSignerConfig: SNPFirmwareSignerConfig{
			AcceptedKeyDigests: idkeydigest.DefaultList(),
			EnforcementPolicy:  idkeydigest.MAAFallback,
		},
		// AMD root key. Received from the AMD Key Distribution System API (KDS).
		AMDRootKey: mustParsePEM(`-----BEGIN CERTIFICATE-----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\nAFZEAwoKCQ==\n-----END CERTIFICATE-----\n`),
	}
}

// GetVariant returns azure-sev-snp as the variant.
func (AzureSEVSNP) GetVariant() variant.Variant {
	return variant.AzureSEVSNP{}
}

// GetMeasurements returns the measurements used for attestation.
func (c AzureSEVSNP) GetMeasurements() measurements.M {
	return c.Measurements
}

// SetMeasurements updates a config's measurements using the given measurements.
func (c *AzureSEVSNP) SetMeasurements(m measurements.M) {
	c.Measurements = m
}

// EqualTo returns true if the config is equal to the given config.
func (c AzureSEVSNP) EqualTo(old AttestationCfg) (bool, error) {
	otherCfg, ok := old.(*AzureSEVSNP)
	if !ok {
		return false, fmt.Errorf("cannot compare %T with %T", c, old)
	}

	firmwareSignerCfgEqual := c.FirmwareSignerConfig.EqualTo(otherCfg.FirmwareSignerConfig)
	measurementsEqual := c.Measurements.EqualTo(otherCfg.Measurements)
	bootloaderEqual := c.BootloaderVersion == otherCfg.BootloaderVersion
	teeEqual := c.TEEVersion == otherCfg.TEEVersion
	snpEqual := c.SNPVersion == otherCfg.SNPVersion
	microcodeEqual := c.MicrocodeVersion == otherCfg.MicrocodeVersion
	rootKeyEqual := bytes.Equal(c.AMDRootKey.Raw, otherCfg.AMDRootKey.Raw)

	return firmwareSignerCfgEqual && measurementsEqual && bootloaderEqual && teeEqual && snpEqual && microcodeEqual && rootKeyEqual, nil
}

// FetchAndSetLatestVersionNumbers fetches the latest version numbers from the configapi and sets them.
func (c *AzureSEVSNP) FetchAndSetLatestVersionNumbers(client fetcher.HTTPClient) error {
	fetcher := fetcher.NewConfigAPIFetcherWithClient(client)
	versions, err := fetcher.FetchLatestAzureSEVSNPVersion(context.Background())
	if err != nil {
		return err
	}
	// set number and keep isLatest flag
	c.mergeVersionNumbers(versions)
	return nil
}

func (c *AzureSEVSNP) mergeVersionNumbers(versions configapi.AzureSEVSNPVersion) {
	c.BootloaderVersion.Value = versions.Bootloader
	c.TEEVersion.Value = versions.TEE
	c.SNPVersion.Value = versions.SNP
	c.MicrocodeVersion.Value = versions.Microcode
}

// AzureTrustedLaunch is the configuration for Azure Trusted Launch attestation.
type AzureTrustedLaunch struct {
	// description: |
	//   Expected TPM measurements.
	Measurements measurements.M `json:"measurements" yaml:"measurements" validate:"required,no_placeholders"`
}

// GetVariant returns azure-trusted-launch as the variant.
func (AzureTrustedLaunch) GetVariant() variant.Variant {
	return variant.AzureTrustedLaunch{}
}

// GetMeasurements returns the measurements used for attestation.
func (c AzureTrustedLaunch) GetMeasurements() measurements.M {
	return c.Measurements
}

// SetMeasurements updates a config's measurements using the given measurements.
func (c *AzureTrustedLaunch) SetMeasurements(m measurements.M) {
	c.Measurements = m
}

// EqualTo returns true if the config is equal to the given config.
func (c AzureTrustedLaunch) EqualTo(other AttestationCfg) (bool, error) {
	otherCfg, ok := other.(*AzureTrustedLaunch)
	if !ok {
		return false, fmt.Errorf("cannot compare %T with %T", c, other)
	}
	return c.Measurements.EqualTo(otherCfg.Measurements), nil
}