package domain

import (
	"fmt"
	"strings"
)

type WikiLink struct {
	target  string
	alias   string
	section string
}

func NewWikiLink(target string, alias string, section string) (*WikiLink, error) {
	if target == "" {
		return nil, fmt.Errorf("wikilink target cannot be empty")
	}

	return &WikiLink{
		target:  target,
		alias:   alias,
		section: section,
	}, nil
}

func (w *WikiLink) Target() string {
	return w.target
}

func (w *WikiLink) Alias() string {
	return w.alias
}

func (w *WikiLink) Section() string {
	return w.section
}

func (w *WikiLink) IsValid() bool {
	return w.target != ""
}

func (w *WikiLink) String() string {
	var parts []string

	if w.alias != "" {
		return fmt.Sprintf("[[%s|%s]]", w.target, w.alias)
	}

	if w.section != "" {
		return fmt.Sprintf("[[%s#%s]]", w.target, w.section)
	}

	return fmt.Sprintf("[[%s]]", w.target)
}

func ParseWikiLink(linkText string) (*WikiLink, error) {
	linkText = strings.Trim(linkText, "[]")

	if linkText == "" {
		return nil, fmt.Errorf("empty wikilink")
	}

	var target, alias, section string

	if strings.Contains(linkText, "|") {
		parts := strings.SplitN(linkText, "|", 2)
		target = strings.TrimSpace(parts[0])
		alias = strings.TrimSpace(parts[1])
	} else if strings.Contains(linkText, "#") {
		parts := strings.SplitN(linkText, "#", 2)
		target = strings.TrimSpace(parts[0])
		section = strings.TrimSpace(parts[1])
	} else {
		target = strings.TrimSpace(linkText)
	}

	return NewWikiLink(target, alias, section)
}