package main

import (
	"fmt"
	"sort"

	bolt "go.etcd.io/bbolt"
)

// Card represents a card on a Kanban board.
type Card struct {
	ID      int
	Title   string
	Content string
}

// Status represents the status of the Kanban board.
type Status struct {
	ID      int
	Name    string
	CardIds []int
	Order   int
}

// ByStatusOrder implements sort.Interface for []Status based on the Order field.
type ByStatusOrder []Status

func (s ByStatusOrder) Len() int {
	return len(s)
}

func (s ByStatusOrder) Swap(i, j int) {
	s[i], s[j] = s[j], s[i]
}

func (s ByStatusOrder) Less(i, j int) bool {
	return s[i].Order < s[j].Order
}

// readStatuses reads all statuses from the database. If there are no statuses in the database then the default
// status list is created and stored in the database. Before returning the status list, the list is ordered based
// on the status' 'Order' field.
// TODO: function needs to be unit tested.
func readStatuses(db *bolt.DB) ([]Status, error) {
	statuses, err := loadAllStatuses(db)
	if err != nil {
		return statuses, fmt.Errorf("unable to read statuses, %w", err)
	}

	if len(statuses) == 0 {
		if err := createDefaultStatusList(db); err != nil {
			return statuses, fmt.Errorf("unable to create the default statuses, %w", err)
		}
		readStatuses(db)
	}

	sort.Sort(ByStatusOrder(statuses))

	return statuses, nil
}

// createDefaultStatusList creates the default list of statuses and saves the statuses to the database.
func createDefaultStatusList(db *bolt.DB) error {
	s := []Status{
		{
			Name:  "To Do",
			Order: 1,
		},
		{
			Name:  "Doing",
			Order: 2,
		},
		{
			Name:  "Done",
			Order: 3,
		},
	}

	return saveStatuses(db, s)
}