// Copyright (C) 2017 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.

package config

import (
	"testing"

	"github.com/syncthing/syncthing/lib/fs"
	"github.com/syncthing/syncthing/lib/structutil"
)

type TestStruct struct {
	Size Size `default:"10%"`
}

func TestSizeDefaults(t *testing.T) {
	x := &TestStruct{}

	structutil.SetDefaults(x)

	if !x.Size.Percentage() {
		t.Error("not percentage")
	}
	if x.Size.Value != 10 {
		t.Error("not ten")
	}
}

func TestParseSize(t *testing.T) {
	cases := []struct {
		in  string
		ok  bool
		val float64
		pct bool
	}{
		// We accept upper case SI units
		{"5K", true, 5e3, false}, // even when they should be lower case
		{"4 M", true, 4e6, false},
		{"3G", true, 3e9, false},
		{"2 T", true, 2e12, false},
		// We accept lower case SI units out of user friendliness
		{"1 k", true, 1e3, false},
		{"2m", true, 2e6, false},
		{"3 g", true, 3e9, false},
		{"4t", true, 4e12, false},
		// Fractions are OK
		{"123.456 k", true, 123.456e3, false},
		{"0.1234 m", true, 0.1234e6, false},
		{"3.45 g", true, 3.45e9, false},
		// We don't parse negative numbers
		{"-1", false, 0, false},
		{"-1k", false, 0, false},
		{"-0.45g", false, 0, false},
		// We accept various unit suffixes on the unit prefix
		{"100 KBytes", true, 100e3, false},
		{"100 Kbps", true, 100e3, false},
		{"100 MAU", true, 100e6, false},
		// Percentages are OK
		{"1%", true, 1, true},
		{"200%", true, 200, true},    // even large ones
		{"200K%", true, 200e3, true}, // even with prefixes, although this makes no sense
		{"2.34%", true, 2.34, true},  // fractions are A-ok
		// The empty string is a valid zero
		{"", true, 0, false},
		{"  ", true, 0, false},
		// Just numbers are fine too
		{"0", true, 0, false},
		{"3", true, 3, false},
		{"34.3", true, 34.3, false},
	}

	for _, tc := range cases {
		size, err := ParseSize(tc.in)

		if !tc.ok {
			if err == nil {
				t.Errorf("Unexpected nil error in UnmarshalText(%q)", tc.in)
			}
			continue
		}

		if err != nil {
			t.Errorf("Unexpected error in UnmarshalText(%q): %v", tc.in, err)
			continue
		}
		if size.BaseValue() > tc.val*1.001 || size.BaseValue() < tc.val*0.999 {
			// Allow 0.1% slop due to floating point multiplication
			t.Errorf("Incorrect value in UnmarshalText(%q): %v, wanted %v", tc.in, size.BaseValue(), tc.val)
		}
		if size.Percentage() != tc.pct {
			t.Errorf("Incorrect percentage bool in UnmarshalText(%q): %v, wanted %v", tc.in, size.Percentage(), tc.pct)
		}
	}
}

func TestFormatSI(t *testing.T) {
	cases := []struct {
		bytes  uint64
		result string
	}{
		{
			bytes:  0,
			result: "0 ", // space for unit
		},
		{
			bytes:  999,
			result: "999 ",
		},
		{
			bytes:  1000,
			result: "1.0 K",
		},
		{
			bytes:  1023 * 1000,
			result: "1.0 M",
		},
		{
			bytes:  5 * 1000 * 1000 * 1000,
			result: "5.0 G",
		},
		{
			bytes:  50000 * 1000 * 1000 * 1000 * 1000,
			result: "50000.0 T",
		},
	}

	for _, tc := range cases {
		res := formatSI(tc.bytes)
		if res != tc.result {
			t.Errorf("formatSI(%d) => %q, expected %q", tc.bytes, res, tc.result)
		}
	}
}

func TestCheckAvailableSize(t *testing.T) {
	cases := []struct {
		req, free, total uint64
		minFree          string
		ok               bool
	}{
		{10, 1e8, 1e9, "1%", true},
		{1e4, 1e3, 1e9, "1%", false},
		{1e2, 1e3, 1e9, "1%", false},
		{1e9, 1 << 62, 1 << 63, "1%", true},
		{10, 1e8, 1e9, "1M", true},
		{1e4, 1e3, 1e9, "1M", false},
		{1e2, 1e3, 1e9, "1M", false},
		{1e9, 1 << 62, 1 << 63, "1M", true},
	}

	for _, tc := range cases {
		minFree, err := ParseSize(tc.minFree)
		if err != nil {
			t.Errorf("Failed to parse %v: %v", tc.minFree, err)
			continue
		}
		usage := fs.Usage{Free: tc.free, Total: tc.total}
		err = checkAvailableSpace(tc.req, minFree, usage)
		t.Log(err)
		if (err == nil) != tc.ok {
			t.Errorf("checkAvailableSpace(%v, %v, %v) == %v, expected %v", tc.req, minFree, usage, err, tc.ok)
		}
	}
}