package db

import (
	"strings"
	"testing"
)

func nonEmpty(stmts []string) []string {
	var out []string
	for _, s := range stmts {
		if strings.TrimSpace(s) != "" {
			out = append(out, s)
		}
	}
	return out
}

func TestSplitSQLBasic(t *testing.T) {
	stmts := nonEmpty(splitSQL("CREATE TABLE a (id int); CREATE TABLE b (id int);"))
	if len(stmts) != 2 {
		t.Fatalf("got %d statements, want 2: %#v", len(stmts), stmts)
	}
}

func TestSplitSQLDollarQuotedFunction(t *testing.T) {
	sql := `CREATE FUNCTION f() RETURNS int AS $$
  SELECT 1; SELECT 2;
$$ LANGUAGE sql;
CREATE TABLE t (id int);`
	stmts := nonEmpty(splitSQL(sql))
	if len(stmts) != 2 {
		t.Fatalf("got %d statements, want 2: %#v", len(stmts), stmts)
	}
	if !strings.Contains(stmts[0], "SELECT 1; SELECT 2;") {
		t.Errorf("dollar-quoted body was split: %q", stmts[0])
	}
}

func TestSplitSQLTaggedDollarQuote(t *testing.T) {
	sql := `DO $body$ BEGIN PERFORM 1; END $body$;SELECT 1;`
	stmts := nonEmpty(splitSQL(sql))
	if len(stmts) != 2 {
		t.Fatalf("got %d statements, want 2: %#v", len(stmts), stmts)
	}
}

func TestSplitSQLSemicolonInComment(t *testing.T) {
	sql := "-- comment with ; semicolon\nCREATE TABLE t (id int); -- trailing; note\nSELECT 1;"
	stmts := nonEmpty(splitSQL(sql))
	if len(stmts) != 2 {
		t.Fatalf("got %d statements, want 2: %#v", len(stmts), stmts)
	}
}

func TestSplitSQLSemicolonInStringLiteral(t *testing.T) {
	sql := `SELECT 'hello; world'; INSERT INTO t VALUES (1);`
	stmts := nonEmpty(splitSQL(sql))
	if len(stmts) != 2 {
		t.Fatalf("got %d statements, want 2: %#v", len(stmts), stmts)
	}
}

func TestSplitSQLDollarSignInStringLiteral(t *testing.T) {
	sql := `SELECT '$100'; SELECT 2;`
	stmts := nonEmpty(splitSQL(sql))
	if len(stmts) != 2 {
		t.Fatalf("got %d statements, want 2: %#v", len(stmts), stmts)
	}
}

func TestSplitSQLBlockComment(t *testing.T) {
	sql := `SELECT 1; /* block; with; semicolons */ SELECT 2;`
	stmts := nonEmpty(splitSQL(sql))
	if len(stmts) != 2 {
		t.Fatalf("got %d statements, want 2: %#v", len(stmts), stmts)
	}
}

func TestSplitSQLBlockCommentWithDollarQuote(t *testing.T) {
	sql := `/* $$ not a dollar quote */ SELECT 1;`
	stmts := nonEmpty(splitSQL(sql))
	if len(stmts) != 1 {
		t.Fatalf("got %d statements, want 1: %#v", len(stmts), stmts)
	}
}

func TestSplitSQLDoubledQuoteInString(t *testing.T) {
	sql := `SELECT 'O''Brien'; SELECT 2;`
	stmts := nonEmpty(splitSQL(sql))
	if len(stmts) != 2 {
		t.Fatalf("got %d statements, want 2: %#v", len(stmts), stmts)
	}
}

func TestSplitSQLEmptyInput(t *testing.T) {
	stmts := nonEmpty(splitSQL(""))
	if len(stmts) != 0 {
		t.Fatalf("got %d statements, want 0", len(stmts))
	}
}

func TestSplitSQLNoSemicolon(t *testing.T) {
	stmts := nonEmpty(splitSQL("SELECT 1"))
	if len(stmts) != 1 {
		t.Fatalf("got %d statements, want 1", len(stmts))
	}
}