package test

import (

"os"

"testing"

"github.com/stretchr/testify/assert"

"github.com/stretchr/testify/require"

"github.com/yyun543/minidb/internal/catalog"

"github.com/yyun543/minidb/internal/executor"

"github.com/yyun543/minidb/internal/optimizer"

"github.com/yyun543/minidb/internal/parser"

"github.com/yyun543/minidb/internal/session"

"github.com/yyun543/minidb/internal/storage"

)

// TestMoRJoinAfterRestart tests the bug where JOIN fails after server restart with MoR delta files

func TestMoRJoinAfterRestart(t *testing.T) {

testDir := "./test_data/mor_join_restart"

os.RemoveAll(testDir)

defer os.RemoveAll(testDir)

// Phase 1: Create tables, insert data, perform UPDATE/DELETE (creates delta files)

t.Log("Phase 1: Creating data and delta files")

{

engine, err := storage.NewParquetEngine(testDir)

require.NoError(t, err)

err = engine.Open()

require.NoError(t, err)

cat := catalog.NewCatalog()

cat.SetStorageEngine(engine)

err = cat.Init()

require.NoError(t, err)

sessMgr, err := session.NewSessionManager()

require.NoError(t, err)

sess := sessMgr.CreateSession()

sess.CurrentDB = "testdb"

opt := optimizer.NewOptimizer()

exec := executor.NewExecutor(cat)

execSQL := func(sql string) error {

stmt, err := parser.Parse(sql)

if err != nil {

return err

}

plan, err := opt.Optimize(stmt)

if err != nil {

return err

}

_, err = exec.Execute(plan, sess)

return err

}

// Create database and tables

err = execSQL("CREATE DATABASE testdb")

require.NoError(t, err)

err = execSQL("CREATE TABLE users (id INT, name VARCHAR, age INT)")

require.NoError(t, err)

err = execSQL("CREATE TABLE orders (id INT, user_id INT, amount INT)")

require.NoError(t, err)

// Insert data

err = execSQL("INSERT INTO users VALUES (1, 'John', 25)")

require.NoError(t, err)

err = execSQL("INSERT INTO users VALUES (2, 'Jane', 30)")

require.NoError(t, err)

err = execSQL("INSERT INTO users VALUES (3, 'Bob', 35)")

require.NoError(t, err)

err = execSQL("INSERT INTO orders VALUES (1, 1, 100)")

require.NoError(t, err)

err = execSQL("INSERT INTO orders VALUES (2, 2, 250)")

require.NoError(t, err)

err = execSQL("INSERT INTO orders VALUES (3, 1, 150)")

require.NoError(t, err)

// Perform UPDATE (creates delta file for users)

err = execSQL("UPDATE users SET name = 'John Doe' WHERE id = 1")

require.NoError(t, err)

// Perform DELETE (creates delta file for orders)

err = execSQL("DELETE FROM orders WHERE amount < 50")

require.NoError(t, err)

// Test JOIN before restart - should work

stmt, err := parser.Parse(`

SELECT u.name, COUNT(o.id) as order_count, SUM(o.amount) as total

FROM users u

LEFT JOIN orders o ON u.id = o.user_id

GROUP BY u.name

HAVING order_count > 1

ORDER BY total DESC

`)

require.NoError(t, err)

plan, err := opt.Optimize(stmt)

require.NoError(t, err)

result, err := exec.Execute(plan, sess)

require.NoError(t, err)

require.NotNil(t, result)

t.Log("✓ JOIN query works BEFORE restart")

err = engine.Close()

require.NoError(t, err)

}

// Phase 2: Restart and test the same JOIN query

t.Log("Phase 2: Restarting and testing JOIN with delta files")

{

engine, err := storage.NewParquetEngine(testDir)

require.NoError(t, err)

err = engine.Open()

require.NoError(t, err)

defer engine.Close()

cat := catalog.NewCatalog()

cat.SetStorageEngine(engine)

err = cat.Init()

require.NoError(t, err)

sessMgr, err := session.NewSessionManager()

require.NoError(t, err)

sess := sessMgr.CreateSession()

sess.CurrentDB = "testdb"

opt := optimizer.NewOptimizer()

exec := executor.NewExecutor(cat)

// Test simple JOIN after restart - this is where the bug occurs

stmt, err := parser.Parse(`

SELECT *

FROM users u

LEFT JOIN orders o ON u.id = o.user_id

`)

require.NoError(t, err)

plan, err := opt.Optimize(stmt)

require.NoError(t, err)

// This should NOT panic (the original bug was here)

result, err := exec.Execute(plan, sess)

require.NoError(t, err, "Simple JOIN query should work AFTER restart with delta files")

require.NotNil(t, result)

// Verify result

totalRows := int64(0)

for _, batch := range result.Batches() {

totalRows += batch.NumRows()

}

assert.Greater(t, totalRows, int64(0), "Should have at least 1 result row from JOIN")

t.Log("✓ Simple JOIN query works AFTER restart")

}

}