package keymigrate

import (
	"fmt"
	"strings"
	"testing"

	"github.com/google/orderedcode"
	"github.com/stretchr/testify/require"
)

func makeKey(t *testing.T, elems ...interface{}) []byte {
	t.Helper()
	out, err := orderedcode.Append([]byte{}, elems...)
	require.NoError(t, err)
	return out
}

func getLegacyPrefixKeys(val int) map[string][]byte {
	vstr := fmt.Sprintf("%02x", byte(val))
	return map[string][]byte{
		"Height":            []byte(fmt.Sprintf("H:%d", val)),
		"BlockPart":         []byte(fmt.Sprintf("P:%d:%d", val, val)),
		"BlockPartTwo":      []byte(fmt.Sprintf("P:%d:%d", val+2, val+val)),
		"BlockCommit":       []byte(fmt.Sprintf("C:%d", val)),
		"SeenCommit":        []byte(fmt.Sprintf("SC:%d", val)),
		"BlockHeight":       []byte(fmt.Sprintf("BH:%x", val)),
		"Validators":        []byte(fmt.Sprintf("validatorsKey:%d", val)),
		"ConsensusParams":   []byte(fmt.Sprintf("consensusParamsKey:%d", val)),
		"ABCIResponse":      []byte(fmt.Sprintf("abciResponsesKey:%d", val)),
		"State":             []byte("stateKey"),
		"CommittedEvidence": append([]byte{0x00}, []byte(fmt.Sprintf("%0.16X/%X", int64(val), []byte("committed")))...),
		"PendingEvidence":   append([]byte{0x01}, []byte(fmt.Sprintf("%0.16X/%X", int64(val), []byte("pending")))...),
		"LightBLock":        []byte(fmt.Sprintf("lb/foo/%020d", val)),
		"Size":              []byte("size"),
		"UserKey0":          []byte(fmt.Sprintf("foo/bar/%d/%d", val, val)),
		"UserKey1":          []byte(fmt.Sprintf("foo/bar/baz/%d/%d", val, val)),
		"TxHeight":          []byte(fmt.Sprintf("tx.height/%s/%d/%d", fmt.Sprint(val), val, val)),
		"TxHash": append(
			[]byte(strings.Repeat(vstr[:1], 16)),
			[]byte(strings.Repeat(vstr[1:], 16))...,
		),

		// Transaction hashes that could be mistaken for evidence keys.
		"TxHashMimic0": append([]byte{0}, []byte(strings.Repeat(vstr, 16)[:31])...),
		"TxHashMimic1": append([]byte{1}, []byte(strings.Repeat(vstr, 16)[:31])...),
	}
}

func getNewPrefixKeys(t *testing.T, val int) map[string][]byte {
	t.Helper()
	vstr := fmt.Sprintf("%02x", byte(val))
	return map[string][]byte{
		"Height":            makeKey(t, int64(0), int64(val)),
		"BlockPart":         makeKey(t, int64(1), int64(val), int64(val)),
		"BlockPartTwo":      makeKey(t, int64(1), int64(val+2), int64(val+val)),
		"BlockCommit":       makeKey(t, int64(2), int64(val)),
		"SeenCommit":        makeKey(t, int64(3), int64(val)),
		"BlockHeight":       makeKey(t, int64(4), int64(val)),
		"Validators":        makeKey(t, int64(5), int64(val)),
		"ConsensusParams":   makeKey(t, int64(6), int64(val)),
		"ABCIResponse":      makeKey(t, int64(7), int64(val)),
		"State":             makeKey(t, int64(8)),
		"CommittedEvidence": makeKey(t, int64(9), int64(val)),
		"PendingEvidence":   makeKey(t, int64(10), int64(val)),
		"LightBLock":        makeKey(t, int64(11), int64(val)),
		"Size":              makeKey(t, int64(12)),
		"UserKey0":          makeKey(t, "foo", "bar", int64(val), int64(val)),
		"UserKey1":          makeKey(t, "foo", "bar/baz", int64(val), int64(val)),
		"TxHeight":          makeKey(t, "tx.height", fmt.Sprint(val), int64(val), int64(val+2), int64(val+val)),
		"TxHash":            makeKey(t, "tx.hash", strings.Repeat(vstr, 16)),
		"TxHashMimic0":      makeKey(t, "tx.hash", "\x00"+strings.Repeat(vstr, 16)[:31]),
		"TxHashMimic1":      makeKey(t, "tx.hash", "\x01"+strings.Repeat(vstr, 16)[:31]),
	}
}

func TestMigration(t *testing.T) {
	t.Run("Idempotency", func(t *testing.T) {
		// we want to make sure that the key space for new and
		// legacy keys are entirely non-overlapping.

		legacyPrefixes := getLegacyPrefixKeys(42)

		newPrefixes := getNewPrefixKeys(t, 42)

		require.Equal(t, len(legacyPrefixes), len(newPrefixes))

		t.Run("Hashes", func(t *testing.T) {
			t.Run("NewKeysAreNotHashes", func(t *testing.T) {
				for _, key := range getNewPrefixKeys(t, 9001) {
					require.True(t, len(key) != 32)
				}
			})
		})
	})
	t.Run("Migrations", func(t *testing.T) {
		t.Run("Errors", func(t *testing.T) {
			table := map[string][]byte{
				"Height":          []byte(fmt.Sprintf("H:%f", 4.22222)),
				"BlockPart":       []byte(fmt.Sprintf("P:%f", 4.22222)),
				"BlockPartTwo":    []byte(fmt.Sprintf("P:%d", 42)),
				"BlockPartThree":  []byte(fmt.Sprintf("P:%f:%f", 4.222, 8.444)),
				"BlockPartFour":   []byte(fmt.Sprintf("P:%d:%f", 4222, 8.444)),
				"BlockCommit":     []byte(fmt.Sprintf("C:%f", 4.22222)),
				"SeenCommit":      []byte(fmt.Sprintf("SC:%f", 4.22222)),
				"BlockHeight":     []byte(fmt.Sprintf("BH:%f", 4.22222)),
				"Validators":      []byte(fmt.Sprintf("validatorsKey:%f", 4.22222)),
				"ConsensusParams": []byte(fmt.Sprintf("consensusParamsKey:%f", 4.22222)),
				"ABCIResponse":    []byte(fmt.Sprintf("abciResponsesKey:%f", 4.22222)),
				"LightBlockShort": []byte(fmt.Sprintf("lb/foo/%010d", 42)),
				"LightBlockLong":  []byte("lb/foo/12345678910.1234567890"),
				"Invalid":         {0x03},
				"BadTXHeight0":    []byte(fmt.Sprintf("tx.height/%s/%f/%f", "boop", 4.4, 4.5)),
				"BadTXHeight1":    []byte(fmt.Sprintf("tx.height/%s/%f", "boop", 4.4)),
				"UserKey0":        []byte("foo/bar/1.3/3.4"),
				"UserKey1":        []byte("foo/bar/1/3.4"),
				"UserKey2":        []byte("foo/bar/baz/1/3.4"),
				"UserKey3":        []byte("foo/bar/baz/1.2/4"),
			}
			for kind, key := range table {
				out, err := migrateKey(key, "")
				// TODO probably these error at the
				// moment because of store missmatches
				require.Error(t, err, kind)
				require.Nil(t, out, kind)
			}
		})
	})
}

func TestGlobalDataStructuresForRefactor(t *testing.T) {
	defer func() {
		if t.Failed() {
			t.Log("number of migrations:", len(migrations))
		}
	}()

	const unPrefixedLegacyKeys = 3

	t.Run("MigrationsAreDefined", func(t *testing.T) {
		if len(prefixes)+unPrefixedLegacyKeys != len(migrations) {
			t.Fatal("migrationse are not correctly defined",
				"prefixes", len(prefixes),
				"migrations", len(migrations))
		}
	})
	t.Run("AllMigrationsHavePrefixDefined", func(t *testing.T) {
		for _, m := range migrations {
			if m.prefix == nil && m.storeName != "tx_index" {
				t.Errorf("migration named %q for store %q does not have a prefix defined", m.name, m.storeName)
			}
		}
	})
	t.Run("Deduplication", func(t *testing.T) {
		t.Run("Prefixes", func(t *testing.T) {
			set := map[string]struct{}{}
			for _, prefix := range prefixes {
				set[string(prefix.prefix)] = struct{}{}
			}
			if len(set) != len(prefixes) {
				t.Fatal("duplicate prefix definition",
					"set", len(set),
					"values", set)
			}
		})
		t.Run("MigrationName", func(t *testing.T) {
			set := map[string]struct{}{}
			for _, migration := range migrations {
				set[migration.name] = struct{}{}
			}
			if len(set) != len(migrations) {
				t.Fatal("duplicate migration name defined",
					"set", len(set),
					"values", set)
			}
		})
		t.Run("MigrationPrefix", func(t *testing.T) {
			set := map[string]struct{}{}
			for _, migration := range migrations {
				set[string(migration.prefix)] = struct{}{}
			}
			// three keys don't have prefixes in the
			// legacy system; this is fine but it means
			// the set will have 1  less than expected
			// (well 2 less, but the empty key takes one
			// of the slots):
			expectedDupl := unPrefixedLegacyKeys - 1

			if len(set) != len(migrations)-expectedDupl {
				t.Fatal("duplicate migration prefix defined",
					"set", len(set),
					"expected", len(migrations)-expectedDupl,
					"values", set)
			}
		})
		t.Run("MigrationStoreName", func(t *testing.T) {
			set := map[string]struct{}{}
			for _, migration := range migrations {
				set[migration.storeName] = struct{}{}
			}
			if len(set) != 5 {
				t.Fatal("duplicate migration store name defined",
					"set", len(set),
					"values", set)
			}
			if _, ok := set[""]; ok {
				t.Fatal("empty store name defined")
			}
		})
	})
	t.Run("NilPrefix", func(t *testing.T) {
		_, err := getMigrationFunc("tx_index", []byte("fooo"))
		if err != nil {
			t.Fatal("should find an index for tx", err)
		}
	})

}