package protocol

import (
	"errors"
	"testing"
)

func TestDetectPostgreSQLClient(t *testing.T) {
	atomicFormats.Store([]format{})
	registerPostgreSQL()

	// 1. A valid PostgreSQL client startup message
	// Format: len (4b), proto (4b), params (n-bytes)
	// Here, user=mazeio, database=test
	// The message is: "user\0mazeio\0database\0test\0\0"
	// Total length: 4 (len) + 4 (proto) + 27 (params) = 35 (0x23)
	pgClientStartup := []byte{
		0x00, 0x00, 0x00, 0x23, // Length: 35
		0x00, 0x03, 0x00, 0x00, // Protocol Version 3.0
		'u', 's', 'e', 'r', 0x00, 'm', 'a', 'z', 'e', 'i', 'o', 0x00,
		'd', 'a', 't', 'a', 'b', 'a', 's', 'e', 0x00, 't', 'e', 's', 't', 0x00, 0x00,
	}

	t.Run("Protocol 3.0", func(t *testing.T) {
		p, c, err := Detect(Client, pgClientStartup, 0, 5432)
		if err != nil {
			t.Fatal(err)
			return
		}
		t.Logf("detected %s version %s confidence %g%%", p.Name, p.Version, 100*c)
		if p.Name != ProtocolPostgreSQL {
			t.Fatalf("expected postgres protocol, got %s", p.Name)
			return
		}
	})
}

func TestDetectPostgreSQLServer(t *testing.T) {
	atomicFormats.Store([]format{})
	registerPostgreSQL()

	// A valid PostgreSQL server AuthenticationOk response
	// Format: type (1b), len (4b), content (4b)
	pgServerAuthOK := []byte{
		'R',                    // Type: Authentication
		0x00, 0x00, 0x00, 0x08, // Length: 8
		0x00, 0x00, 0x00, 0x00, // Auth OK (0)
	}

	// A valid PostgreSQL server ErrorResponse
	pgServerError := []byte{
		'E',                    // Type: ErrorResponse
		0x00, 0x00, 0x00, 0x31, // Length
		'S', 'E', 'R', 'R', 'O', 'R', 0x00, // ... and so on
	}

	// Invalid data (HTTP GET request)
	httpBanner := []byte("GET / HTTP/1.1\r\nHost: example.com\r\n\r\n")

	t.Run("AuthenticationOk", func(t *testing.T) {
		p, c, err := Detect(Server, pgServerAuthOK, 5432, 0)
		if err != nil {
			t.Fatal(err)
			return
		}
		t.Logf("detected %s version %s confidence %g%%", p.Name, p.Version, c*100)
		if p.Name != ProtocolPostgreSQL {
			t.Fatalf("expected postgres protocol, got %s", p.Name)
			return
		}
	})

	t.Run("ErrorResponse", func(t *testing.T) {
		p, c, err := Detect(Server, pgServerError, 5432, 0)
		if err != nil {
			t.Fatal(err)
			return
		}
		t.Logf("detected %s version %s confidence %g%%", p.Name, p.Version, c*100)
		if p.Name != ProtocolPostgreSQL {
			t.Fatalf("expected postgres protocol, got %s", p.Name)
			return
		}
	})

	t.Run("Invalid HTTP", func(t *testing.T) {
		_, _, err := Detect(Server, httpBanner, 0, 80)
		if !errors.Is(err, ErrUnknown) {
			t.Fatalf("expected unknown format, got error %T: %q", err, err)
		} else {
			t.Logf("error %q, as expected", err)
		}
	})
}