package main

import (
  "context"
  "fmt"

  "github.com/ClickHouse/ch-go"
  "github.com/ClickHouse/ch-go/proto"
)

func main() {
  ctx := context.Background()
  c, err := ch.Dial(ctx, ch.Options{Address: "localhost:9000"})
  if err != nil {
    panic(err)
  }
  var (
    numbers int
    data    proto.ColUInt64
  )
  if err := c.Do(ctx, ch.Query{
    Body: "SELECT number FROM system.numbers LIMIT 500000000",
    Result: proto.Results{
      {Name: "number", Data: &data},
    },
    // OnResult will be called on next received data block.
    OnResult: func(ctx context.Context, b proto.Block) error {
      numbers += len(data)
      return nil
    },
  }); err != nil {
    panic(err)
  }
  fmt.Println("numbers:", numbers)
}

var result proto.Results
q := ch.Query{
  Body:   "SELECT * FROM table",
  Result: result.Auto(),
}

var res proto.ColBool
q := ch.Query{
  Body:   "SELECT v FROM test_table",
  Result: proto.ResultColumn{Data: &res},
}

var (
	body      proto.ColStr
	name      proto.ColStr
	sevText   proto.ColEnum
	sevNumber proto.ColUInt8

	ts  = new(proto.ColDateTime64).WithPrecision(proto.PrecisionNano) // DateTime64(9)
	arr = new(proto.ColStr).Array()                                   // Array(String)
	now = time.Date(2010, 1, 1, 10, 22, 33, 345678, time.UTC)
)

// Append 10 rows to initial data block.
for i := 0; i < 10; i++ {
	body.AppendBytes([]byte("Hello"))
	ts.Append(now)
	name.Append("name")
	sevText.Append("INFO")
	sevNumber.Append(10)
	arr.Append([]string{"foo", "bar", "baz"})
}

input := proto.Input{
	{Name: "ts", Data: ts},
	{Name: "severity_text", Data: &sevText},
	{Name: "severity_number", Data: sevNumber},
	{Name: "body", Data: body},
	{Name: "name", Data: name},
	{Name: "arr", Data: arr},
}

if err := conn.Do(ctx, ch.Query{
	// Or "INSERT INTO test_table_insert (ts, severity_text, severity_number, body, name, arr) VALUES"
	// Or input.Into("test_table_insert")
	Body: "INSERT INTO test_table_insert VALUES",
	Input: input,
}); err != nil {
	panic(err)
}

// Stream data to ClickHouse server in multiple data blocks.
var blocks int
if err := conn.Do(ctx, ch.Query{
	Body:  input.Into("test_table_insert"), // helper that generates INSERT INTO query with all columns
	Input: input,

	// OnInput is called to prepare Input data before encoding and sending
	// to ClickHouse server.
	OnInput: func(ctx context.Context) error {
		// On OnInput call, you should fill the input data.
		//
		// NB: You should reset the input columns, they are
		// not reset automatically.
		//
		// That is, we are re-using the same input columns and
		// if we will return nil without doing anything, data will be
		// just duplicated.

		input.Reset() // calls "Reset" on each column

		if blocks >= 10 {
			// Stop streaming.
			//
			// This will also write tailing input data if any,
			// but we just reset the input, so it is currently blank.
			return io.EOF
		}

		// Append new values:
		for i := 0; i < 10; i++ {
			body.AppendBytes([]byte("Hello"))
			ts.Append(now)
			name.Append("name")
			sevText.Append("DEBUG")
			sevNumber.Append(10)
			arr.Append([]string{"foo", "bar", "baz"})
		}

		// Data will be encoded and sent to ClickHouse server after returning nil.
		// The Do method will return error if any.
		blocks++
		return nil
	},
}); err != nil {
	panic(err)
}

var (
    colK proto.ColInt64
    colV proto.ColInt64
)
// Generate some data.
for i := 0; i < 100; i++ {
    colK.Append(int64(i))
    colV.Append(int64(i) + 1000)
}
// Write data to buffer.
var buf proto.Buffer
input := proto.Input{
    {"k", colK},
    {"v", colV},
}
b := proto.Block{
    Rows:    colK.Rows(),
    Columns: len(input),
}
// Note that we are using version 54451, proto.Version will fail.
if err := b.EncodeRawBlock(&buf, 54451, input); err != nil {
    panic(err)
}

// You can write buf.Buf to io.Writer, e.g. os.Stdout or file.
var out bytes.Buffer
_, _ = out.Write(buf.Buf)

// You can encode multiple buffers in sequence.
//
// To do this, reset buf and all columns, append new values
// to columns and call EncodeRawBlock again.
buf.Reset()
colV.Reset()
colV.Reset()

var v proto.ColEnum8

const ddl = `'Foo'=1, 'Bar'=2, 'Baz'=3`
input := []proto.InputColumn{
  {Name: "v", Data: proto.Wrap(&v, ddl)},
}

type ColumnOf[T any] interface {
	Column
	Append(v T)
	AppendArr(vs []T)
	Row(i int) T
}

// Array(String)
arr := proto.NewArray[string](new(proto.ColStr))
// Or
arr := new(proto.ColStr).Array()
q := ch.Query{
  Body:   "SELECT ['foo', 'bar', 'baz']::Array(String) as v",
  Result: arr.Results("v"),
}
// Do ...
arr.Row(0) // ["foo", "bar", "baz"]

func TestDump(t *testing.T) {
	// Testing decoding of Native format dump.
	//
	// CREATE TABLE test_dump (id Int8, v String)
	//   ENGINE = MergeTree()
	// ORDER BY id;
	//
	// SELECT * FROM test_dump
	//   ORDER BY id
	// INTO OUTFILE 'test_dump_native.raw' FORMAT Native;
	data, err := os.ReadFile(filepath.Join("_testdata", "test_dump_native.raw"))
	require.NoError(t, err)
	var (
		dec    proto.Block
		ids    proto.ColInt8
		values proto.ColStr
	)
	require.NoError(t, dec.DecodeRawBlock(
		proto.NewReader(bytes.NewReader(data)),
		proto.Results{
			{Name: "id", Data: &ids},
			{Name: "v", Data: &values},
		}),
	)
}

func TestLocalNativeDump(t *testing.T) {
	ctx := context.Background()
	// Testing clickhouse-local.
	var v proto.ColStr
	for _, s := range data {
		v.Append(s)
	}
	buf := new(proto.Buffer)
	b := proto.Block{Rows: 2, Columns: 2}
	require.NoError(t, b.EncodeRawBlock(buf, 54451, []proto.InputColumn{
		{Name: "title", Data: v},
		{Name: "data", Data: proto.ColInt64{1, 2}},
	}), "encode")

	dir := t.TempDir()
	inFile := filepath.Join(dir, "data.native")
	require.NoError(t, os.WriteFile(inFile, buf.Buf, 0600), "write file")

	cmd := exec.Command("clickhouse-local", "local",
		"--logger.console",
		"--log-level", "trace",
		"--file", inFile,
		"--input-format", "Native",
		"--output-format", "JSON",
		"--query", "SELECT * FROM table",
	)
	out := new(bytes.Buffer)
	errOut := new(bytes.Buffer)
	cmd.Stdout = out
	cmd.Stderr = errOut

	t.Log(cmd.Args)
	require.NoError(t, cmd.Run(), "run: %s", errOut)
	t.Log(errOut)

	v := struct {
		Rows int `json:"rows"`
		Data []struct {
			Title string `json:"title"`
			Data  int    `json:"data,string"`
		}
	}{}
	require.NoError(t, json.Unmarshal(out.Bytes(), &v), "json")
	assert.Equal(t, 2, v.Rows)
	if assert.Len(t, v.Data, 2) {
		for i, r := range []struct {
			Title string `json:"title"`
			Data  int    `json:"data,string"`
		}{
			{"Foo", 1},
			{"Bar", 2},
		} {
			assert.Equal(t, r, v.Data[i])
		}
	}
}