// This file is part of arduino-cli.
//
// Copyright 2020 ARDUINO SA (http://www.arduino.cc/)
//
// This software is released under the GNU General Public License version 3,
// which covers the main part of arduino-cli.
// The terms of this license can be found at:
// https://www.gnu.org/licenses/gpl-3.0.en.html
//
// You can be released from the requirements of the above licenses by purchasing
// a commercial license. Buying such a license is mandatory if you want to
// modify or otherwise use the software for commercial activities involving the
// Arduino software without disclosing the source code of your own applications.
// To purchase a commercial license, send an email to license@arduino.cc.

package daemon

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"strings"

	"github.com/arduino/arduino-cli/configuration"
	rpc "github.com/arduino/arduino-cli/rpc/cc/arduino/cli/settings/v1"
)

// SettingsService implements the `Settings` service
type SettingsService struct{}

// GetAll returns a message with a string field containing all the settings
// currently in use, marshalled in JSON format.
func (s *SettingsService) GetAll(ctx context.Context, req *rpc.GetAllRequest) (*rpc.GetAllResponse, error) {
	b, err := json.Marshal(configuration.Settings.AllSettings())
	if err == nil {
		return &rpc.GetAllResponse{
			JsonData: string(b),
		}, nil
	}

	return nil, err
}

// mapper converts a map of nested maps to a map of scalar values.
// For example:
//    {"foo": "bar", "daemon":{"port":"420"}, "sketch": {"always_export_binaries": "true"}}
// would convert to:
//    {"foo": "bar", "daemon.port":"420", "sketch.always_export_binaries": "true"}
func mapper(toMap map[string]interface{}) map[string]interface{} {
	res := map[string]interface{}{}
	for k, v := range toMap {
		switch data := v.(type) {
		case map[string]interface{}:
			for mK, mV := range mapper(data) {
				// Concatenate keys
				res[fmt.Sprintf("%s.%s", k, mK)] = mV
			}
			// This is done to avoid skipping keys containing empty maps
			if len(data) == 0 {
				res[k] = map[string]interface{}{}
			}
		default:
			res[k] = v
		}
	}
	return res
}

// Merge applies multiple settings values at once.
func (s *SettingsService) Merge(ctx context.Context, req *rpc.MergeRequest) (*rpc.MergeResponse, error) {
	var toMerge map[string]interface{}
	if err := json.Unmarshal([]byte(req.GetJsonData()), &toMerge); err != nil {
		return nil, err
	}

	mapped := mapper(toMerge)

	// Set each value individually.
	// This is done because Viper ignores empty strings or maps when
	// using the MergeConfigMap function.
	for k, v := range mapped {
		configuration.Settings.Set(k, v)
	}

	return &rpc.MergeResponse{}, nil
}

// GetValue returns a settings value given its key. If the key is not present
// an error will be returned, so that we distinguish empty settings from missing
// ones.
func (s *SettingsService) GetValue(ctx context.Context, req *rpc.GetValueRequest) (*rpc.GetValueResponse, error) {
	key := req.GetKey()

	// Check if settings key actually existing, we don't use Viper.InConfig()
	// since that doesn't check for keys formatted like daemon.port or those set
	// with Viper.Set(). This way we check for all existing settings for sure.
	keyExists := false
	for _, k := range configuration.Settings.AllKeys() {
		if k == key || strings.HasPrefix(k, key) {
			keyExists = true
			break
		}
	}
	if !keyExists {
		return nil, errors.New("key not found in settings")
	}

	b, err := json.Marshal(configuration.Settings.Get(key))
	value := &rpc.GetValueResponse{}
	if err == nil {
		value.Key = key
		value.JsonData = string(b)
	}

	return value, err
}

// SetValue updates or set a value for a certain key.
func (s *SettingsService) SetValue(ctx context.Context, val *rpc.SetValueRequest) (*rpc.SetValueResponse, error) {
	key := val.GetKey()
	var value interface{}

	err := json.Unmarshal([]byte(val.GetJsonData()), &value)
	if err == nil {
		configuration.Settings.Set(key, value)
	}

	return &rpc.SetValueResponse{}, err
}

// Write to file set in request the settings currently stored in memory.
// We don't have a Read() function, that's not necessary since we only want one config file to be used
// and that's picked up when the CLI is run as daemon, either using the default path or a custom one
// set with the --config-file flag.
func (s *SettingsService) Write(ctx context.Context, req *rpc.WriteRequest) (*rpc.WriteResponse, error) {
	if err := configuration.Settings.WriteConfigAs(req.FilePath); err != nil {
		return nil, err
	}
	return &rpc.WriteResponse{}, nil
}
