package board_test

import (
	"errors"
	"os"
	"path/filepath"
	"reflect"
	"sort"
	"testing"
	"time"

	"codeflow.dananglin.me.uk/apollo/pelican/internal/board"
)

func TestCardLifecycle(t *testing.T) {
	t.Log("Testing the lifecycle of a couple of cards...")

	projectDir, err := projectRoot()
	if err != nil {
		t.Fatalf(err.Error())
	}

	testDBPath := filepath.Join(projectDir, "test", "databases", "Board_TestCardLifecycle.db")
	os.Remove(testDBPath)

	kanban, err := board.Open(testDBPath)
	if err != nil {
		t.Fatalf("Unable to open the test Kanban board, %s.", err)
	}

	defer func() {
		_ = kanban.Close()
	}()

	t.Logf("We've opened a new board, let us create a couple of cards...")

	cardArgs := map[int]board.CardArgs{
		1: {
			NewTitle:       "Test Card 01",
			NewDescription: "Ensure that the cards are safely stored in the database.",
		},
		2: {
			NewTitle:       "Test Card 02",
			NewDescription: "Ensure that cards can be modified and that the modifications are saved in the database.",
		},
		3: {
			NewTitle:       "Test Card 03",
			NewDescription: "Ensure that cards can be deleted from the database.",
		},
	}

	timestamp := time.Now().Format(time.DateTime)

	t.Run("Test Create Cards", testCreateCards(kanban, cardArgs))

	t.Logf("Now that we've created some cards, let's retrieve one from the database...")

	t.Run("Test Read One Card", testReadOneCard(kanban, 1, cardArgs[1], timestamp))

	t.Logf("Let us try retrieving multiple cards...")

	subCardArgs := make(map[int]board.CardArgs)
	subCardArgs[2] = cardArgs[2]
	subCardArgs[3] = cardArgs[3]

	t.Run("Test Read Multiple Cards", testReadManyCards(kanban, subCardArgs))

	t.Logf("Let's see what happens when trying to read a card that does not exist in the database...")

	t.Run("Test Read Non-Existent Card", testReadNonExistentCard(kanban, 1000))

	t.Logf("Let us try modifying the title and description of one of the cards...")

	modifiedCardArgs := board.UpdateCardArgs{
		CardID: 1,
		CardArgs: board.CardArgs{
			NewTitle:       cardArgs[1].NewTitle + " (edited).",
			NewDescription: "This description has been edited.",
		},
	}

	t.Run("Test Update Card", testUpdateCard(kanban, modifiedCardArgs, timestamp))

	t.Logf("Let us also try only modifying the description of a card...")

	expectedCardContent := "Only the description is updated in this card."

	modifiedCardArgs = board.UpdateCardArgs{
		CardID: 2,
		CardArgs: board.CardArgs{
			NewTitle:       "",
			NewDescription: expectedCardContent,
		},
	}

	expectedCardTitle := "Test Card 02"

	t.Run("Test Update Card Content Only", testUpdateCardContent(kanban, modifiedCardArgs, expectedCardTitle, expectedCardContent, timestamp))

	t.Logf("Let's now delete a card from the database...")

	t.Run("Test Card Delete", testDeleteCard(kanban, 1, 1, []int{2, 3}))
}

func testCreateCards(kanban board.Board, args map[int]board.CardArgs) func(t *testing.T) {
	return func(t *testing.T) {
		t.Log("When creating and saving the cards to the database.")

		for i := 1; i <= len(args); i++ {
			if _, err := kanban.CreateCard(args[i]); err != nil {
				t.Fatalf("ERROR: Unable to create the test card, %s.", err)
			}
		}

		t.Logf("%s\tAll cards have been saved to the database.", success)

		t.Logf("\tVerifying that the card IDs are present the status in first position...")

		statusList, err := kanban.StatusList()
		if err != nil {
			t.Fatalf("ERROR: Unable to retrieve the list of statuses; %v", err)
		}

		if len(statusList) == 0 {
			t.Fatal("ERROR: No statuses were returned from the database.")
		}

		expectedStatus := statusList[0]

		wantCardIDs := []int{1, 2, 3}

		if !reflect.DeepEqual(expectedStatus.CardIds, wantCardIDs) {
			t.Errorf("%s\tUnexpected card IDs found in the expected status, want: %v, got %v.", failure, wantCardIDs, expectedStatus.CardIds)
		} else {
			t.Logf("%s\tExpected card IDs found in the expected status, got %v.", success, expectedStatus.CardIds)
		}
	}
}

func testReadOneCard(kanban board.Board, cardID int, cardArgs board.CardArgs, wantTimestamp string) func(t *testing.T) {
	return func(t *testing.T) {
		t.Log("When reading a card from the database.")

		card, err := kanban.Card(cardID)
		if err != nil {
			t.Fatalf("ERROR: Unable to read test card, %s.", err)
		}

		wantTitle := cardArgs.NewTitle
		if card.Title != wantTitle {
			t.Errorf("%s\tUnexpected card title received, want: %q, got: %q.", failure, wantTitle, card.Title)
		} else {
			t.Logf("%s\tExpected card title received, got: %q.", success, card.Title)
		}

		wantDescription := cardArgs.NewDescription
		if card.Description != cardArgs.NewDescription {
			t.Errorf("%s\tUnexpected card content received, want: %q, got: %q.", failure, wantDescription, card.Description)
		} else {
			t.Logf("%s\tExpected card content received, got: %q.", success, card.Description)
		}

		if card.Created != wantTimestamp {
			t.Errorf("%s\tUnexpected timestamp received for the created card, want: %q, got %q.", failure, wantTimestamp, card.Created)
		} else {
			t.Logf("%s\tExpected timestamp received for the created card, got: %q.", success, card.Created)
		}
	}
}

func testReadManyCards(kanban board.Board, cardArgs map[int]board.CardArgs) func(t *testing.T) {
	return func(t *testing.T) {
		t.Log("When reading multiple cards from the database.")

		var cardIDList []int
		for key := range cardArgs {
			cardIDList = append(cardIDList, key)
		}

		cards, err := kanban.CardList(cardIDList)
		if err != nil {
			t.Fatalf("ERROR: Unable to retrieve the list of cards from the database; %v", err)
		}

		for i := range cards {
			cardID := cards[i].GetID()
			wantTitle := cardArgs[cardID].NewTitle
			gotTitle := cards[i].Title

			if wantTitle != gotTitle {
				t.Errorf("%s\tUnexpected card title received, want: %q, got: %q.", failure, wantTitle, gotTitle)
			} else {
				t.Logf("%s\tExpected card title received, got: %q.", success, gotTitle)
			}
		}
	}
}

func testReadNonExistentCard(kanban board.Board, cardID int) func(t *testing.T) {
	return func(t *testing.T) {
		t.Log("When attempting to retrieving a non-existent card from the database.")

		_, err := kanban.Card(cardID)

		switch {
		case err == nil:
			t.Errorf("%s\tWanted an error for retrieving a non-existent card but got 'nil' instead.", failure)
		case errors.As(err, &board.CardNotExistError{}):
			t.Logf("%s\tExpected error received after attempting to retrieve a non-existent card from the database; got '%v'", success, err)
		default:
			t.Errorf("%s\tUnexpected error received after attempting to retrieve a non-existent card from the database; got: '%v'", failure, err)
		}
	}
}

func testUpdateCard(kanban board.Board, modifiedCardArgs board.UpdateCardArgs, timestamp string) func(t *testing.T) {
	return func(t *testing.T) {
		t.Log("When a card is updated in the database.")

		if err := kanban.UpdateCard(modifiedCardArgs); err != nil {
			t.Fatalf("ERROR: Unable to update the test card, %s", err)
		}

		got, err := kanban.Card(modifiedCardArgs.CardID)
		if err != nil {
			t.Fatalf("ERROR: Unable to read the modified test card, %s", err)
		}

		want := board.Card{
			Identity:    board.Identity{ID: modifiedCardArgs.CardID},
			Title:       modifiedCardArgs.NewTitle,
			Description: modifiedCardArgs.NewDescription,
			Created:     timestamp,
		}

		if !reflect.DeepEqual(got, want) {
			t.Errorf("%s\tUnexpected card read from the database: want %+v, got %+v", failure, want, got)
		} else {
			t.Logf("%s\tExpected card read from the database: got %+v", success, got)
		}
	}
}

func testUpdateCardContent(kanban board.Board, modifiedCardArgs board.UpdateCardArgs, expectedTitle, expectedDescription, timestamp string) func(t *testing.T) {
	return func(t *testing.T) {
		t.Log("When (and only when) a card's content is updated in the database.")

		if err := kanban.UpdateCard(modifiedCardArgs); err != nil {
			t.Fatalf("ERROR: Unable to update the test card, %s", err)
		}

		got, err := kanban.Card(modifiedCardArgs.CardID)
		if err != nil {
			t.Fatalf("ERROR: Unable to read the modified test card, %s", err)
		}

		want := board.Card{
			Identity:    board.Identity{ID: modifiedCardArgs.CardID},
			Title:       expectedTitle,
			Description: expectedDescription,
			Created:     timestamp,
		}

		if !reflect.DeepEqual(got, want) {
			t.Errorf("%s\tUnexpected card read from the database, want: %+v, got: %+v", failure, want, got)
		} else {
			t.Logf("%s\tExpected card read from the database, got: %+v", success, got)
		}
	}
}

func testDeleteCard(kanban board.Board, cardID, statusID int, expectedCardIDs []int) func(t *testing.T) {
	return func(t *testing.T) {
		t.Log("When deleting a card from the database.")

		args := board.DeleteCardArgs{
			CardID:   cardID,
			StatusID: statusID,
		}

		if err := kanban.DeleteCard(args); err != nil {
			t.Fatalf("ERROR: An error occurred when deleting the card from the database, %v", err)
		} else {
			t.Logf("%s\tNo errors occurred when deleting the card from the database.", success)
		}

		t.Logf("\tVerifying that the card is removed from the database...")

		_, err := kanban.Card(cardID)

		switch {
		case err == nil:
			t.Errorf("%s\tDid not receive the expected error when attempting to read the deleted card.", failure)
		case errors.As(err, &board.CardNotExistError{}):
			t.Logf("%s\tSuccessfully received board.CardNotExistError when attempting to retrieve the deleted card.", success)
		default:
			t.Errorf(
				"%s\tDid not receive the expected error when attempting to retrieve the deleted card; got '%v'.",
				failure,
				err,
			)
		}

		t.Logf("\tVerifying that the card's ID is removed from the status list...")

		status, err := kanban.Status(statusID)
		if err != nil {
			t.Fatalf("ERROR: Unable to read status '%d' from the database; %v", statusID, err)
		}

		sort.Ints(expectedCardIDs)
		sort.Ints(status.CardIds)

		if !reflect.DeepEqual(status.CardIds, expectedCardIDs) {
			t.Errorf("%s\tUnexpected list of card IDs found in status '%d'; want %v, got %v", failure, statusID, expectedCardIDs, status.CardIds)
		} else {
			t.Logf("%s\tExpected list of card IDs found in status '%d'; got %v", success, statusID, status.CardIds)
		}
	}
}