/*
Copyright 2022 CAcert Inc.
SPDX-License-Identifier: Apache-2.0

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package hsm

import (
	"context"
	"errors"
	"fmt"

	"github.com/ThalesIgnite/crypto11"

	"git.cacert.org/cacert-gosigner/pkg/config"
)

type ctxKey int

const (
	ctxCADirectory ctxKey = iota
	ctxP11Contexts
	ctxSetupMode
	ctxSignerConfig
	ctxVerboseLogging
)

type ConfigOption func(ctx context.Context) context.Context

func CADirectoryOption(path string) func(ctx context.Context) context.Context {
	return func(ctx context.Context) context.Context {
		return context.WithValue(ctx, ctxCADirectory, path)
	}
}

func CaConfigOption(signerConfig *config.SignerConfig) func(context.Context) context.Context {
	return func(ctx context.Context) context.Context {
		return context.WithValue(ctx, ctxSignerConfig, signerConfig)
	}
}

func SetupModeOption() func(context.Context) context.Context {
	return func(ctx context.Context) context.Context {
		return context.WithValue(ctx, ctxSetupMode, true)
	}
}

func VerboseLoggingOption() func(ctx context.Context) context.Context {
	return func(ctx context.Context) context.Context {
		return context.WithValue(ctx, ctxVerboseLogging, true)
	}
}

// SetupContext sets global context for HSM operations.
func SetupContext(options ...ConfigOption) context.Context {
	ctx := context.Background()

	ctx = context.WithValue(ctx, ctxP11Contexts, make(map[string]*crypto11.Context))

	for _, opt := range options {
		ctx = opt(ctx)
	}

	return ctx
}

func GetSignerConfig(ctx context.Context) *config.SignerConfig {
	signerConfig, ok := ctx.Value(ctxSignerConfig).(*config.SignerConfig)
	if !ok {
		return nil
	}

	return signerConfig
}

func IsSetupMode(ctx context.Context) bool {
	setupMode, ok := ctx.Value(ctxSetupMode).(bool)
	if !ok {
		return false
	}

	return setupMode
}

func IsVerbose(ctx context.Context) bool {
	verbose, ok := ctx.Value(ctxVerboseLogging).(bool)
	if !ok {
		return false
	}

	return verbose
}

func GetP11Context(ctx context.Context, entry *config.CaCertificateEntry) (*crypto11.Context, error) {
	contexts, ok := ctx.Value(ctxP11Contexts).(map[string]*crypto11.Context)
	if !ok {
		return nil, errors.New("type assertion failed, use hsm.SetupContext first")
	}

	if p11Context, ok := contexts[entry.Storage]; ok {
		return p11Context, nil
	}

	p11Context, err := prepareCrypto11Context(ctx, entry.Storage)
	if err != nil {
		return nil, err
	}

	contexts[entry.Storage] = p11Context

	return p11Context, nil
}

func CloseP11Contexts(ctx context.Context) error {
	contexts, ok := ctx.Value(ctxP11Contexts).(map[string]*crypto11.Context)
	if !ok {
		return errors.New("type assertion failed, use hsm.SetupContext first")
	}

	seen := make(map[*crypto11.Context]struct{}, 0)

	for _, p11Context := range contexts {
		if _, ok := seen[p11Context]; ok {
			continue
		}

		seen[p11Context] = struct{}{}

		err := p11Context.Close()
		if err != nil {
			return fmt.Errorf("could not close context: %w", err)
		}
	}

	return nil
}