package buildfile

import (
	"bytes"
	"github.com/xdrm-brackets/nix-amer/internal/instruction"
	"testing"
)

func TestNullContext(t *testing.T) {
	buffer := bytes.NewBufferString("")
	_, err := NewReader(nil, buffer)
	if err != ErrNullContext {
		t.Fatalf("expected <%s>, got <%v>", ErrNullContext, err)
	}
}
func TestIgnoreCommentsAndEmptyLines(t *testing.T) {
	ctx, _ := instruction.CreateContext("apt-get", "")
	buffer := bytes.NewBufferString("# some comment\n;other comment\n  \t  \n\t  \t\n; other comment after empty lines")

	r, err := NewReader(ctx, buffer)
	if err != nil {
		t.Fatalf("unexpected error <%v>", err)
	}

	if len(r.Content) > 0 {
		t.Fatalf("expected no content, got %d instructions", len(r.Content))
	}
}

func TestInstructionSyntax(t *testing.T) {
	tests := []struct {
		File string
		Line int
		Err  error
	}{
		{"[pre]\ninstall args\ndelete args\n", 1, nil},
		{"[pre]\n install args\ndelete args\n", 1, nil},
		{"[pre]\n\tinstall args\ndelete args\n", 1, nil},
		{"[pre]\n \t install args\ndelete args\n", 1, nil},
		{"[pre]\n \t install args\ndelete args\n", 1, nil},

		{"[pre]\ncmd args\ncmd args\n", 2, instruction.ErrUnknownInstruction},
		{"[pre]\ninstall args\ncmd args\n", 3, instruction.ErrUnknownInstruction},
		{"[pre]\n cmd args\ncmd args\n", 2, instruction.ErrUnknownInstruction},
		{"[pre]\n\tcmd args\ncmd args\n", 2, instruction.ErrUnknownInstruction},
		{"[pre]\n \t cmd args\ncmd args\n", 2, instruction.ErrUnknownInstruction},
		{"[pre]\n \t cmd args\ncmd args\n", 2, instruction.ErrUnknownInstruction},

		{"[pre]\ncmd args\ncmd\n", 2, instruction.ErrUnknownInstruction},
		{"[pre]\ninstall\ncmd args\n", 2, instruction.ErrInvalidSyntax},

		{"[pre]\ninstall args\n cmd args\n", 3, instruction.ErrUnknownInstruction},
		{"[pre]\ninstall args\ncmd\n", 3, instruction.ErrInvalidSyntax},
	}

	ctx, _ := instruction.CreateContext("apt-get", "")

	for i, test := range tests {

		// create reader
		buffer := bytes.NewBufferString(test.File)
		_, err := NewReader(ctx, buffer)

		// no error expected
		if test.Err == nil {
			if err != nil {
				lineerr, ok := err.(LineError)
				if !ok {
					t.Errorf("[%d] expect error to be of type <LineError>", i)
					continue
				}
				t.Errorf("[%d] expect no error, got <%s>", i, lineerr.Err)
			}
			continue
		} else if err == nil {
			t.Errorf("[%d] expect error <%s>, got none", i, test.Err)
			continue
		}

		lineerr := err.(LineError)

		// error expected
		if lineerr.Err != test.Err {
			t.Errorf("[%d] expect error <%s>, got <%s>", i, test.Err, lineerr.Err)
			continue
		}

		if lineerr.Line != test.Line {
			t.Errorf("[%d] expect error at line %d, got %d", i, test.Line, lineerr.Line)
		}

	}
}