package main

import (
	"bytes"
	"errors"
	"fmt"
	"sort"
	"strings"
)

var (
	ErrInvalidURL = errors.New("that's not a valid URL")
	ErrNotAMark   = errors.New("that's not a known mark name")
)

func MarkAdd(state *BrowserState, name, target string) error {
	u, _, err := parseURL(target, state, state.DefaultScheme)
	if err != nil {
		return ErrInvalidURL
	}

	state.Marks[name] = u.String()
	if err := saveMarks(state.Marks); err != nil {
		return err
	}

	state.Modal = []byte(fmt.Sprintf("Saved mark %s to %s\n", name, u.String()))
	return Print(state)
}

func MarkGo(state *BrowserState, name string) error {
	_, target, err := findMark(state, name)
	if err != nil {
		return err
	}

	return Go(state, target)
}

func MarkList(state *BrowserState) error {
	names := make([]string, 0, len(state.Marks))
	for name := range state.Marks {
		names = append(names, name)
	}
	sort.Strings(names)

	buf := &bytes.Buffer{}
	for _, name := range names {
		_, err := fmt.Fprintf(buf, "%s: %s\n", name, state.Marks[name])
		if err != nil {
			return err
		}
	}
	state.Modal = buf.Bytes()
	if len(state.Modal) == 0 {
		state.Modal = []byte("(no marks)\n")
	}
	return Print(state)
}

func MarkDelete(state *BrowserState, name string) error {
	name, _, err := findMark(state, name)
	if err != nil {
		return err
	}
	delete(state.Marks, name)
	if err := saveMarks(state.Marks); err != nil {
		return err
	}

	state.Modal = []byte(fmt.Sprintf("Deleted mark %s\n", name))
	return Print(state)
}

func findMark(state *BrowserState, prefix string) (string, string, error) {
	found := 0
	fullname := ""
	value := ""
	for name, target := range state.Marks {
		if strings.HasPrefix(name, prefix) {
			found += 1
			value = target
			fullname = name
		}
	}

	switch found {
	case 0:
		return "", "", ErrNotAMark
	case 1:
		return fullname, value, nil
	default:
		return "", "", fmt.Errorf("too ambiguous - found %d matching marks", found)
	}
}