package main

import (
	"fmt"
	"os"
	"strings"
	"testing"
)

func TestMigrationNumber(t *testing.T) {
	n := len(migrations)

	entries, err := os.ReadDir(migrationDir)
	if err != nil {
		t.Fatalf("Failed to determine number of migration files: %v", err)
	}
	expectation := len(entries)

	if n != expectation {
		t.Fatalf("Expected %d migration files but got %d.", expectation, n)
	}
}

func TestMigrationContent(t *testing.T) {
	for i, migration := range migrations {
		path := migrationPath(i)

		expectation := fmt.Sprintf("PRAGMA user_version = %d;", i+1)
		if !strings.HasPrefix(migration, expectation) {
			t.Fatalf("Expected '%s' at start of '%s'.", expectation, path)
		}
	}
}

func TestMigrations(t *testing.T) {
	db, _ := emptyDB(t)

	userVersion, err := UserVersion(db)
	if err != nil {
		t.Fatalf("Failed to get initial user_version: %v", err)
	}

	if userVersion != 0 {
		t.Fatalf("Expected user_version 0 but got %d.", userVersion)
	}

	for i := range migrations {
		path := migrationPath(i)

		err := Migrate(db, i)
		if err != nil {
			t.Fatalf("Failed to execute migration %s: %v", path, err)
		}

		userVersion, err = UserVersion(db)
		if err != nil {
			t.Fatalf("Failed to get user_version after migration: %v", err)
		}

		expected := i + 1
		if userVersion != expected {
			t.Fatalf(
				"Expected user_version %d after running %s but got %d.",
				expected,
				path,
				userVersion,
			)
		}
	}
}