package cnf

import (
	lib "git.xdrm.io/go/nix-amer/internal/cnf/parser/nginx"
	"io"
	"strings"
)

type nginx struct {
	data   *lib.Model
	parsed bool
}

// ReadFrom implements io.ReaderFrom
func (d *nginx) ReadFrom(_reader io.Reader) (int64, error) {

	d.data = new(lib.Model)

	// 1. get nginx decoder
	decoder := lib.NewDecoder(_reader)
	err := decoder.Decode(d.data)
	if err != nil {
		return 0, err
	}

	d.parsed = true
	return 0, nil

}

// WriteTo implements io.WriterTo
func (d *nginx) WriteTo(_writer io.Writer) (int64, error) {
	encoder := lib.NewEncoder(_writer)
	return 0, encoder.Encode(d.data)
}

// browse returns the target of a dot-separated path (as an interface{} chain where the last is the target if found)
func (d *nginx) browse(_path string) ([][]*lib.Line, bool) {

	// 1. extract path
	path := strings.Split(_path, ".")
	if len(path) > 0 { // remove last field
		path = path[:len(path)-1]
	}

	// 2. init output chain
	var current []*lib.Line = d.data.Lines
	chain := make([][]*lib.Line, 0, len(path)+1)
	chain = append(chain, current)

	// 3. iterate over path / nested fields
	for _, field := range path {

		for _, child := range current {
			if child.Type == lib.SECTION && child.Components[0] == field {
				current = child.Lines
				chain = append(chain, current)
				break
			}
		}

		return chain, false
	}

	return chain, true
}

// Get returns the value of a dot-separated path, and if it exists
func (d *nginx) Get(_path string) (string, bool) {

	// 1. browse path
	chain, found := d.browse(_path)
	if !found {
		return "", false
	}

	// 2. Get last field
	fields := strings.Split(_path, ".")
	field := fields[len(fields)-1]

	// 3. search in last chain element
	last := chain[len(chain)-1]

	for _, line := range last {

		// 4. return value
		if line.Type == lib.ASSIGNMENT && line.Components[0] == field {
			return line.Components[1], true
		}

	}

	return "", false

}

// Set the value of a dot-separated path, and creates it if not found
func (d *nginx) Set(_path, _value string) bool {

	return false

}