/*
 * Wiki - A wiki with editor
 * Copyright (c) 2021 Peter Stuifzand
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package main

import (
	"time"
)

func combine(x, y Change) Change {
	x.Count++
	if x.Body == "" {
		x.Body = y.Body
	} else {
		x.Body += " " + y.Body
	}
	x.EndDate = y.Date

	return x
}

func changeEqual(x, y Change) bool {
	return x.Page == y.Page && x.Date.Truncate(24*time.Hour) == y.Date.Truncate(24*time.Hour)
}

func groupRecentChanges(changes []Change) int {
	if len(changes) <= 1 {
		return 0
	}

	f := len(changes) - 1
	i := f - 1

	for {
		if changeEqual(changes[f], changes[i]) {
			changes[f] = combine(changes[f], changes[i])
		} else {
			f--
			changes[f] = changes[i]
		}

		if i <= 0 {
			break
		}

		i--
	}

	return f
}