package tdb

import (
	"errors"
	"fmt"
	"log"
	"math/rand"
	"os"
	"reflect"
	"strings"
	"testing"
	"time"

	// "encoding/ascii85"
	// "log"
	// "strconv"

	"git.keganmyers.com/terribleplan/tdb/stringy"

	bolt "go.etcd.io/bbolt"
)

const debug = false

type testDb struct {
	db            DB
	TEST_Main     Table
	TEST_OwnedBy  Table
	TEST_ArrayHas Table
}

const (
	letterBytes   = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
	letterIdxBits = 6                    // 6 bits to represent a letter index
	letterIdxMask = 1<<letterIdxBits - 1 // All 1-bits, as many as letterIdxBits
	letterIdxMax  = 63 / letterIdxBits   // # of letter indices fitting in 63 bits
)

var src = rand.NewSource(time.Now().UnixNano())

func randomString(n int) string {
	sb := strings.Builder{}
	sb.Grow(n)
	// A src.Int63() generates 63 random bits, enough for letterIdxMax characters!
	for i, cache, remain := n-1, src.Int63(), letterIdxMax; i >= 0; {
		if remain == 0 {
			cache, remain = src.Int63(), letterIdxMax
		}
		if idx := int(cache & letterIdxMask); idx < len(letterBytes) {
			sb.WriteByte(letterBytes[idx])
			i--
		}
		cache >>= letterIdxBits
		remain--
	}

	return sb.String()
}

var tdb *testDb
var testFilename string

func setupCustomTestDb(tb interface{}, schema func(db DBSetup) error) DB {
	if debug {
		log.Print("- Creating test database")
	}

	testFilename = fmt.Sprintf("%s_test.testdb", randomString(16))
	b, err := bolt.Open(testFilename, 0600, nil)
	if err != nil {
		panic(fmt.Errorf("Unable to create test DB '%s'", testFilename))
	}

	if db, err := New(b, tb, schema); err != nil {
		panic(err)
	} else {
		return db
	}
}

func setupTestDb() {
	tdb = &testDb{}

	db := setupCustomTestDb(tdb, func(db DBSetup) error {
		db.SetDebug(debug)
		db.AddTableOrPanic(&TEST_Main{}, func(t TableSetup) error {
			return nil
		})
		db.AddTableOrPanic(&TEST_OwnedBy{}, func(t TableSetup) error {
			t.AddIndexOrPanic(SimpleIndexOptions{
				ConstraintOptions: ConstraintOptions{
					Field:   "MainId",
					Foreign: "TEST_Main",
					NotNull: true,
				},
			})
			return nil
		})
		db.AddTableOrPanic(&TEST_ArrayHas{}, func(t TableSetup) error {
			t.AddArrayIndexOrPanic(ArrayIndexOptions{
				ElementsNotNull: true,
				ConstraintOptions: ConstraintOptions{
					Field:   "MainIds",
					Foreign: "TEST_Main",
					NotNull: true,
				},
			})
			return nil
		})
		return nil
	})

	tdb.db = db

	if tdb.TEST_Main == nil {
		panic(errors.New("tdb.TEST_Main was not set"))
	}

	if tdb.TEST_OwnedBy == nil {
		panic(errors.New("tdb.TEST_OwnedBy was not set"))
	}
}

func cleanupTestDb() {
	if debug {
		log.Print("- Closing test database")
	}
	tdb.db.Close()
	err := os.Remove(testFilename)
	testFilename = ""
	if err != nil {
		panic(err)
	}
	if debug {
		log.Print("- Closed test database")
	}
	return
}

func assertUint64Equal(t *testing.T, actual, expected uint64, message string) {
	assertUint64EqualEnd(t, actual, expected, message)
}

func assertUint64EqualEnd(t *testing.T, actual, expected uint64, message string) bool {
	if actual != expected {
		t.Errorf("%s: got %s, expected %s", message, stringy.ToStringOrPanic(actual), stringy.ToStringOrPanic(expected))
		return true
	}
	return false
}

func assertEqual(t *testing.T, actual, expected interface{}, message string) {
	assertEqualEnd(t, actual, expected, message)
}

func assertEqualEnd(t *testing.T, actual, expected interface{}, message string) bool {
	if actual != expected {
		t.Errorf("%s: got %s, expected %s", message, stringy.ToStringOrPanic(actual), stringy.ToStringOrPanic(expected))
		return true
	}
	return false
}

func assertNotEqual(t *testing.T, actual, expected interface{}, message string) {
	assertNotEqualEnd(t, actual, expected, message)
}

func assertNotEqualEnd(t *testing.T, actual, expected interface{}, message string) bool {
	if actual == expected {
		t.Errorf("%s: got %s, expected anything else", message, stringy.ToStringOrPanic(actual))
		return true
	}
	return false
}

func assertNotNil(t *testing.T, actual interface{}, message string) {
	assertNotNilEnd(t, actual, message)
}

func assertNotNilEnd(t *testing.T, actual interface{}, message string) bool {
	if actual == nil {
		t.Errorf("%s: got %#v, expected non-nil", message, actual)
		return true
	}
	return false
}

func assertNil(t *testing.T, actual interface{}, message string) {
	assertNilEnd(t, actual, message)
}

// typed nil is stupid
func assertNilEnd(t *testing.T, actual interface{}, message string) bool {
	if actual != nil {
		av := reflect.ValueOf(actual)
		if !av.IsValid() {
			return false
		}
		if !av.IsNil() || !av.IsZero() {
			t.Errorf("%s: got %#v, expected nil", message, actual)
			return true
		}
	}
	return false
}

func assertOk(t *testing.T, actual bool, message string) {
	assertOkEnd(t, actual, message)
}

func assertOkEnd(t *testing.T, actual bool, message string) bool {
	if !actual {
		t.Errorf("%s: expected to be ok", message)
		return true
	}
	return false
}

func dumpBuckets(db *bolt.DB) {
	fmt.Printf("\n----------\nbuckets:\n\n")
	if err := db.View(func(tx *bolt.Tx) error {
		return tx.ForEach(func(name []byte, _ *bolt.Bucket) error {
			fmt.Printf("%s\n", name)
			return nil
		})
	}); err != nil {
		fmt.Printf("\nerror while dumping buckets: %s", err.Error())
	}
}

func dumpKeyspace(db *bolt.DB, bucket string) {
	fmt.Printf("\n----------\nkeys in '%s':\n\n", bucket)
	if err := db.View(func(tx *bolt.Tx) error {
		b := tx.Bucket([]byte(bucket))
		if b == nil {
			fmt.Printf("  (nil bucket)")
			return nil
		}

		c := b.Cursor()
		for k, _ := c.First(); k != nil; k, _ = c.Next() {
			fmt.Printf("%s\n", k)
		}
		return nil
	}); err != nil {
		fmt.Printf("\nerror while dumping keys: %s", err.Error())
	}
}