package partman

import (
	"fmt"
	"time"
)

const (
	daysInWeek = 7
)

type weeklyPartition struct {
	t time.Time
}

func (d weeklyPartition) PartitionName() string {
	return fmt.Sprintf("calls_p_%d_w%02d_%02d", d.t.Year(), d.t.Month(), d.t.Day())
}

func (d weeklyPartition) Range() (start, end time.Time) {
	start = time.Date(d.t.Year(), d.t.Month(), d.t.Day(), 0, 0, 0, 0, d.t.UTC().Location()).AddDate(0, 0, -int(d.t.Weekday()-time.Monday))
	start = start.AddDate(0, 0, daysInWeek)

	return
}

func (d weeklyPartition) Next(i int) partition {
	year, month, day := d.t.Date()

	return weeklyPartition{
		t: time.Date(year, month, day+i, 0, 0, 0, 0, time.UTC),
	}
}

func (d weeklyPartition) Prev(i int) partition {
	year, month, day := d.t.Date()

	return weeklyPartition{
		t: time.Date(year, month, day-i, 0, 0, 0, 0, d.t.Location()),
	}
}

type dailyPartition struct {
	t time.Time
}

func (d dailyPartition) PartitionName() string {
	return fmt.Sprintf("calls_p_%d_%02d_%02d", d.t.Year(), d.t.Month(), d.t.Day())
}

func (d dailyPartition) Range() (start, end time.Time) {
	start = time.Date(d.t.Year(), d.t.Month(), d.t.Day(), 0, 0, 0, 0, time.UTC)
	end = start.AddDate(0, 0, 1)

	return
}

func (d dailyPartition) Next(i int) partition {
	year, month, day := d.t.Date()

	return dailyPartition{
		t: time.Date(year, month, day+i, 0, 0, 0, 0, time.UTC),
	}
}

func (d dailyPartition) Prev(i int) partition {
	year, month, day := d.t.Date()

	return dailyPartition{
		t: time.Date(year, month, day-i, 0, 0, 0, 0, d.t.Location()),
	}
}

type monthlyPartition struct {
	t time.Time
}

func (d monthlyPartition) PartitionName() string {
	return fmt.Sprintf("calls_p_%d_%02d", d.t.Year(), d.t.Month())
}

func (d monthlyPartition) Range() (start, end time.Time) {
	start = time.Date(d.t.Year(), d.t.Month(), 1, 0, 0, 0, 0, time.UTC)
	end = start.AddDate(0, 1, 0)

	return
}

func (d monthlyPartition) Next(i int) partition {
	year, month, _ := d.t.Date()

	return monthlyPartition{
		t: time.Date(year, month+time.Month(i), 1, 0, 0, 0, 0, time.UTC),
	}
}

func (d monthlyPartition) Prev(i int) partition {
	year, month, _ := d.t.Date()

	return monthlyPartition{
		t: time.Date(year, month-time.Month(i), 1, 0, 0, 0, 0, d.t.Location()),
	}
}