package main

import (
	"bytes"
	"os"
	"path/filepath"
	"strings"
	"testing"
)

func TestFmtStdin(t *testing.T) {
	in := strings.NewReader("create function f() returns int language sql as $$ select 1 $$;\n")
	var out, errb bytes.Buffer
	rc := run([]string{"fmt"}, in, &out, &errb)
	if rc != 0 {
		t.Fatalf("rc=%d stderr=%s", rc, errb.String())
	}
	if !strings.HasPrefix(out.String(), "CREATE FUNCTION f(") {
		t.Errorf("unexpected output:\n%s", out.String())
	}
}

func TestFmtCheckStdin(t *testing.T) {
	unformatted := "create function f() returns int language sql as $$ select 1 $$;"

	// Unformatted input → rc 1.
	var out, errb bytes.Buffer
	if rc := run([]string{"fmt", "--check"}, strings.NewReader(unformatted), &out, &errb); rc != 1 {
		t.Errorf("unformatted input: rc=%d, want 1", rc)
	}

	// Its own formatted output → rc 0 (idempotent + check agree).
	out.Reset()
	errb.Reset()
	run([]string{"fmt"}, strings.NewReader(unformatted), &out, &errb)
	formatted := out.String()
	var out2, errb2 bytes.Buffer
	if rc := run([]string{"fmt", "--check"}, strings.NewReader(formatted), &out2, &errb2); rc != 0 {
		t.Errorf("formatted input: rc=%d, want 0\noutput was:\n%s", rc, formatted)
	}
}

func TestFmtWriteInPlace(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "f.pgsql")
	orig := "create function f() returns int language sql as $$ select 1 $$;\n"
	if err := os.WriteFile(path, []byte(orig), 0o644); err != nil {
		t.Fatal(err)
	}
	var out, errb bytes.Buffer
	if rc := run([]string{"fmt", "-w", path}, nil, &out, &errb); rc != 0 {
		t.Fatalf("rc=%d stderr=%s", rc, errb.String())
	}
	got, _ := os.ReadFile(path)
	if string(got) == orig {
		t.Error("file was not rewritten")
	}
	// Second write is a no-op (idempotent).
	if rc := run([]string{"fmt", "--check", path}, nil, &out, &errb); rc != 0 {
		t.Errorf("after -w, --check rc=%d, want 0", rc)
	}
}

func TestUnknownCommand(t *testing.T) {
	var out, errb bytes.Buffer
	if rc := run([]string{"frobnicate"}, nil, &out, &errb); rc != 2 {
		t.Errorf("rc=%d, want 2", rc)
	}
}