package pgserver

import (
	"testing"
)

func TestAlterTableAddColumnOverSimpleQuery(t *testing.T) {
	c, client := newDataConnection(t)
	runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte("CREATE TABLE t (id INTEGER PRIMARY KEY)"), 0)})
	runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte("INSERT INTO t (id) VALUES (1)"), 0)})

	runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte("ALTER TABLE t ADD COLUMN IF NOT EXISTS note TEXT DEFAULT 'later'"), 0)})
	// Idempotent second boot-time migration.
	runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte("ALTER TABLE t ADD COLUMN IF NOT EXISTS note TEXT DEFAULT 'later'"), 0)})

	msgs := runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte("SELECT id, note FROM t ORDER BY id"), 0)})
	values := dataRowValues(t, msgs[1])
	if len(values) != 2 || values[0] != "1" || values[1] != "later" {
		t.Fatalf("existing row after ADD COLUMN = %v, want [1 later]", values)
	}

	runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte("INSERT INTO t (id) VALUES (2)"), 0)})
	msgs = runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte("SELECT note FROM t WHERE id = 2"), 0)})
	if got := dataRowValues(t, msgs[1]); len(got) != 1 || got[0] != "later" {
		t.Fatalf("new row note = %v, want [later]", got)
	}
}

func TestAlterTableAddColumnErrorsOverSimpleQuery(t *testing.T) {
	c, client := newDataConnection(t)
	runQuery(t, c, client, &Message{Type: MsgQuery, Data: []byte("CREATE TABLE t (id INTEGER PRIMARY KEY)\x00")})
	runQuery(t, c, client, &Message{Type: MsgQuery, Data: []byte("INSERT INTO t (id) VALUES (1), (2)\x00")})

	// A required column with no default cannot be materialized for existing
	// rows.
	msgs := runQuery(t, c, client, &Message{Type: MsgQuery, Data: []byte("ALTER TABLE t ADD COLUMN note TEXT NOT NULL\x00")})
	if code := errorCode(msgs[0]); code != "23502" {
		t.Fatalf("NOT NULL without default SQLSTATE = %q, want 23502", code)
	}

	// Backfilling one constant into two rows violates the declared UNIQUE
	// constraint.
	msgs = runQuery(t, c, client, &Message{Type: MsgQuery, Data: []byte("ALTER TABLE t ADD COLUMN code TEXT DEFAULT 'same' UNIQUE\x00")})
	if code := errorCode(msgs[0]); code != "23505" {
		t.Fatalf("UNIQUE backfill SQLSTATE = %q, want 23505", code)
	}

	msgs = runQuery(t, c, client, &Message{Type: MsgQuery, Data: []byte("ALTER TABLE t ADD COLUMN note TEXT NOT NULL DEFAULT 'kept'\x00")})
	if code := errorCode(msgs[0]); code != "" {
		t.Fatalf("NOT NULL with default SQLSTATE = %q, want success", code)
	}
	msgs = runQuery(t, c, client, &Message{Type: MsgQuery, Data: []byte("SELECT note FROM t ORDER BY id\x00")})
	for i, values := range []string{"kept", "kept"} {
		got := dataRowValues(t, msgs[1+i])
		if len(got) != 1 || got[0] != values {
			t.Fatalf("row %d note = %v, want [%s]", i, got, values)
		}
	}
}

func TestAlterTableDropAndRenameColumnOverSimpleQuery(t *testing.T) {
	c, client := newDataConnection(t)
	runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte("CREATE TABLE t (id INTEGER PRIMARY KEY, keep TEXT, dropme TEXT)"), 0)})
	runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte("INSERT INTO t (id, keep, dropme) VALUES (1, 'a', 'gone')"), 0)})

	runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte("ALTER TABLE t DROP COLUMN dropme"), 0)})
	runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte("ALTER TABLE t RENAME COLUMN keep TO kept"), 0)})

	msgs := runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte("SELECT kept FROM t WHERE id = 1"), 0)})
	if got := dataRowValues(t, msgs[1]); len(got) != 1 || got[0] != "a" {
		t.Fatalf("renamed column value = %v, want [a]", got)
	}

	msgs = runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte("SELECT dropme FROM t"), 0)})
	if code := errorCode(msgs[0]); code == "" {
		t.Fatalf("expected an error selecting a dropped column, got %v", msgs)
	}
}