// Copyright 2024 Matthew Rich <matthewrich.conf@gmail.com>. All rights reserved.

package config

import (
	"context"
	"encoding/json"
	"github.com/ProtonMail/go-crypto/openpgp"

	"io"
	"strings"
	"strconv"
	"gopkg.in/yaml.v3"
	"decl/internal/data"
	"decl/internal/codec"
	"fmt"
	"log/slog"
)

type OpenPGPKeyRing struct {
	Keyring string `json:"keyring,omitempty" yaml:"keyring,omitempty"` 
	entities openpgp.EntityList
}

func NewOpenPGPKeyRing() *OpenPGPKeyRing {
	o := &OpenPGPKeyRing{}
	return o
}

func (o *OpenPGPKeyRing) URI() string {
	return fmt.Sprintf("%s://%s", o.Type(), "")
}

func (o *OpenPGPKeyRing) SetURI(uri string) error {
	return nil
}

func (o *OpenPGPKeyRing) SetParsedURI(uri data.URIParser) error {
	return nil
}

func (o *OpenPGPKeyRing) Read(ctx context.Context) (yamlData []byte, err error) {
	pemReader := io.NopCloser(strings.NewReader(o.Keyring))
	o.entities, err = openpgp.ReadArmoredKeyRing(pemReader)
	return
}

func (o *OpenPGPKeyRing) Load(r io.Reader) (err error) {
	err = codec.NewYAMLDecoder(r).Decode(o)
	if err == nil {
		_, err = o.Read(context.Background())
	}
	return err
}

func (o *OpenPGPKeyRing) LoadYAML(yamlData string) (err error) {
	err = codec.NewYAMLStringDecoder(yamlData).Decode(o)
	slog.Info("OpenPGP.LoadYAML()", "keyring", len(o.Keyring), "err", err)
	if err == nil {
		_, err = o.Read(context.Background())
	}
	return err
}

func (o *OpenPGPKeyRing) UnmarshalJSON(data []byte) error {
	if unmarshalErr := json.Unmarshal(data, o); unmarshalErr != nil {
		return unmarshalErr
	}
	//o.NewReadConfigCommand()
	return nil
}

func (o *OpenPGPKeyRing) UnmarshalYAML(value *yaml.Node) error {
	type decodeOpenPGP OpenPGPKeyRing
	if unmarshalErr := value.Decode((*decodeOpenPGP)(o)); unmarshalErr != nil {
		return unmarshalErr
	}
	return nil
}

func (o *OpenPGPKeyRing) Clone() data.Configuration {
	jsonGeneric, _ := json.Marshal(o)
	clone := NewOpenPGPKeyRing()
	if unmarshalErr := json.Unmarshal(jsonGeneric, &clone); unmarshalErr != nil {
		panic(unmarshalErr)
	}
	return clone
}

func (o *OpenPGPKeyRing) Type() string {
	return "openpgp"
}

func (o *OpenPGPKeyRing) GetEntityIndex(key string) (index int, field string, err error) {
	values := strings.SplitN(key, ".", 2)
	if len(values) == 2 {
		if index, err = strconv.Atoi(values[0]); err == nil {
			field = values[1]
		}
	} else {
		err = data.ErrUnknownConfigurationKey
	}
	return
}

func (o *OpenPGPKeyRing) GetValue(name string) (result any, err error) {
	index, field, err := o.GetEntityIndex(name)
	if len(o.entities) > index && err == nil {
		switch field {
		case "PublicKey":
			return o.entities[index].PrimaryKey, err
		case "PrivateKey":
			return o.entities[index].PrimaryKey, err
		}
	}
	err = data.ErrUnknownConfigurationKey
	return
}


// Expected key: 0.PrivateKey
func (o *OpenPGPKeyRing) Has(key string) (ok bool) {
	index, field, err := o.GetEntityIndex(key)
	if len(o.entities) > index && err == nil {
		switch field {
		case "PublicKey":
			ok = o.entities[index].PrimaryKey != nil
		case "PrivateKey":
			ok = o.entities[index].PrimaryKey != nil
		}
	}
	return
}