package parser

import "bufio"

var parsers map[string]Parser

func init() {
	parsers = make(map[string]Parser, 0)

	addParser(&CPUParser{})
	addParser(&MemoryParser{})
}

func addParser(p Parser) {
	parsers[p.Key()] = p
}

func GetParser(name string) Parser {
	p, ok := parsers[name]
	if !ok {
		return nil
	}
	return p
}

type Parser interface {
	Key() string
	Parse(scanner *ParserScanner) (map[string]string, error)
}

type ParserScanner struct {
	scanner  *bufio.Scanner
	boundary string

	text string

	ended bool
	eof   bool
}

func (ps *ParserScanner) Clean() bool {
	if ps.eof {
		return false
	}

	if ps.ended {
		ps.ended = false
		return true
	}

	for ps.scanner.Scan() {
		line := ps.scanner.Text()
		if line == "--"+ps.boundary+"--" {
			ps.eof = true
			return false
		}

		if line == "--"+ps.boundary {
			break
		}
	}
	return true
}

func (ps *ParserScanner) EOF() bool {
	return ps.eof
}

func (ps *ParserScanner) Scan() bool {
	if ps.eof || ps.ended {
		return false
	}

	if !ps.scanner.Scan() {
		return false
	}

	line := ps.scanner.Text()
	if line == "--"+ps.boundary+"--" {
		ps.eof = true
		return false
	}

	if line == "--"+ps.boundary {
		ps.ended = true
		return false
	}

	ps.text = line
	return true
}

func (ps *ParserScanner) Text() string {
	if ps.eof || ps.ended {
		return ""
	}
	return ps.text
}

func (ps *ParserScanner) Err() error {
	return ps.scanner.Err()
}

func NewParserScanner(scanner *bufio.Scanner, boundary string) *ParserScanner {
	ps := &ParserScanner{
		scanner:  scanner,
		boundary: boundary,
	}

	return ps
}