package parser

import (
	"fmt"
	"github.com/buger/jsonparser"
	"github.com/magiconair/properties"
	"github.com/pkg/errors"
	"go.uber.org/zap"
	"os"
)

type ConfigurationParser string

// The file parsing options that are available for a server configuration file.
const (
	File       = "file"
	Yaml       = "yaml"
	Properties = "properties"
	Ini        = "ini"
	Json       = "json"
	Xml        = "xml"
)

// Defines a configuration file for the server startup. These will be looped over
// and modified before the server finishes booting.
type ConfigurationFile struct {
	FileName string                         `json:"file"`
	Parser   ConfigurationParser            `json:"parser"`
	Replace  []ConfigurationFileReplacement `json:"replace"`
}

// Defines a single find/replace instance for a given server configuration file.
type ConfigurationFileReplacement struct {
	Match     string               `json:"match"`
	Value     string               `json:"value"`
	ValueType jsonparser.ValueType `json:"-"`
}

func (cfr *ConfigurationFileReplacement) UnmarshalJSON(data []byte) error {
	if m, err := jsonparser.GetString(data, "match"); err != nil {
		return err
	} else {
		cfr.Match = m
	}

	if v, dt, _, err := jsonparser.Get(data, "value"); err != nil {
		return err
	} else {
		if dt != jsonparser.String && dt != jsonparser.Number && dt != jsonparser.Boolean {
			return errors.New(
				fmt.Sprintf("cannot parse JSON: received unexpected replacement value type: %d", dt),
			)
		}

		cfr.Value = string(v)
		cfr.ValueType = dt
	}

	return nil
}

// Parses a given configuration file and updates all of the values within as defined
// in the API response from the Panel.
func (f *ConfigurationFile) Parse(path string) error {
	zap.S().Debugw("parsing configuration file", zap.String("path", path), zap.String("parser", string(f.Parser)))

	switch f.Parser {
	case Properties:
		f.parsePropertiesFile(path)
		break
	}

	return nil
}

// Parses a properties file and updates the values within it to match those that
// are passed. Writes the file once completed.
func (f *ConfigurationFile) parsePropertiesFile(path string) error {
	p, err := properties.LoadFile(path, properties.UTF8)
	if err != nil {
		return errors.WithStack(err)
	}

	for _, replace := range f.Replace {
		if _, _, err := p.Set(replace.Match, replace.Value); err != nil {
			return errors.WithStack(err)
		}
	}

	w, err := os.OpenFile(path, os.O_CREATE|os.O_WRONLY, 0644);
	if err != nil {
		return errors.WithStack(err)
	}

	_, err = p.Write(w, properties.UTF8)

	return err
}