go-todotxt/sort.go

122 lines
2.9 KiB
Go

package todotxt
import (
"errors"
"sort"
"time"
)
// Flags for defining sort element and order.
const (
SortPriorityAsc = iota
SortPriorityDesc
SortCreatedDateAsc
SortCreatedDateDesc
SortCompletedDateAsc
SortCompletedDateDesc
SortDueDateAsc
SortDueDateDesc
)
// Sort allows a TodoList to be sorted by certain predefined fields.
// See constants SORT_* for fields and sort order.
func (todolist *TodoList) Sort(sortFlag int) error {
switch sortFlag {
case SortPriorityAsc, SortPriorityDesc:
todolist.sortByPriority(sortFlag)
case SortCreatedDateAsc, SortCreatedDateDesc:
todolist.sortByCreatedDate(sortFlag)
case SortCompletedDateAsc, SortCompletedDateDesc:
todolist.sortByCompletedDate(sortFlag)
case SortDueDateAsc, SortDueDateDesc:
todolist.sortByDueDate(sortFlag)
default:
return errors.New("unrecognized sort option")
}
return nil
}
func (todolist *TodoList) refresh() {
todolist.Sort(todolist.SortFlag)
for i, t := range todolist.Todos {
t.Id = i
}
}
type todolistSort struct {
todolists TodoList
by func(t1, t2 *Todo) bool
}
func (ts *todolistSort) Len() int {
return len(ts.todolists.Todos)
}
func (ts *todolistSort) Swap(l, r int) {
ts.todolists.Todos[l], ts.todolists.Todos[r] = ts.todolists.Todos[r], ts.todolists.Todos[l]
}
func (ts *todolistSort) Less(l, r int) bool {
return ts.by(ts.todolists.Todos[l], ts.todolists.Todos[r])
}
func (todolist *TodoList) sortBy(by func(t1, t2 *Todo) bool) *TodoList {
ts := &todolistSort{
todolists: *todolist,
by: by,
}
sort.Sort(ts)
return todolist
}
func (todolist *TodoList) sortByPriority(order int) *TodoList {
todolist.sortBy(func(t1, t2 *Todo) bool {
if order == SortPriorityAsc { // ASC
if t1.HasPriority() && t2.HasPriority() {
return t1.Priority < t2.Priority
}
return t1.HasPriority()
}
// DESC
if t1.HasPriority() && t2.HasPriority() {
return t1.Priority > t2.Priority
}
return !t1.HasPriority()
})
return todolist
}
func sortByDate(asc bool, hasDate1, hasDate2 bool, date1, date2 time.Time) bool {
if asc { // ASC
if hasDate1 && hasDate2 {
return date1.Before(date2)
}
return hasDate2
}
// DESC
if hasDate1 && hasDate2 {
return date1.After(date2)
}
return !hasDate2
}
func (todolist *TodoList) sortByCreatedDate(order int) *TodoList {
todolist.sortBy(func(t1, t2 *Todo) bool {
return sortByDate(order == SortCreatedDateAsc, t1.HasCreatedDate(), t2.HasCreatedDate(), t1.CreatedDate, t2.CreatedDate)
})
return todolist
}
func (todolist *TodoList) sortByCompletedDate(order int) *TodoList {
todolist.sortBy(func(t1, t2 *Todo) bool {
return sortByDate(order == SortCompletedDateAsc, t1.HasCompletedDate(), t2.HasCompletedDate(), t1.CompletedDate, t2.CompletedDate)
})
return todolist
}
func (todolist *TodoList) sortByDueDate(order int) *TodoList {
todolist.sortBy(func(t1, t2 *Todo) bool {
return sortByDate(order == SortDueDateAsc, t1.HasDueDate(), t2.HasDueDate(), t1.DueDate, t2.DueDate)
})
return todolist
}