package config

import (
	"bytes"
	"flag"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestInt(t *testing.T) {
	flags := flag.NewFlagSet("test", 0)
	var context struct {
		Number int `default:"5" usage:"some number"`
	}
	require.NotPanics(t, func() {
		AddOptionsToSet(flags, &context, "")
	})
	require.Equal(t, []simpleFlag{
		{
			name:     "number",
			usage:    "some number",
			defValue: "5",
		}},
		allFlags(flags))
	assert.Equal(t, 5, context.Number)
}

func TestLower(t *testing.T) {
	flags := flag.NewFlagSet("test", 0)
	var context struct {
		Ahem      string
		MixedCase string
	}
	require.NotPanics(t, func() {
		AddOptionsToSet(flags, &context, "")
	})
	require.Equal(t, []simpleFlag{
		{
			name: "ahem",
		},
		{
			name: "mixedcase",
		},
	},
		allFlags(flags))
}

func TestPrefix(t *testing.T) {
	flags := flag.NewFlagSet("test", 0)
	var context struct {
		Number int `usage:"some number"`
	}
	require.NotPanics(t, func() {
		AddOptionsToSet(flags, &context, "some.prefix")
	})
	require.Equal(t, []simpleFlag{
		{
			name:     "some.prefix.number",
			usage:    "some number",
			defValue: "0",
		}},
		allFlags(flags))
}

func TestRecursion(t *testing.T) {
	flags := flag.NewFlagSet("test", 0)
	type Nested struct {
		Number1 int `usage:"embedded number"`
	}
	var context struct {
		Nested
		A struct {
			B struct {
				C struct {
					Number2 int `usage:"some number"`
				}
			}
		}
	}
	require.NotPanics(t, func() {
		AddOptionsToSet(flags, &context, "")
	})
	require.Equal(t, []simpleFlag{
		{
			name:     "a.b.c.number2",
			usage:    "some number",
			defValue: "0",
		},
		{
			name:     "number1",
			usage:    "embedded number",
			defValue: "0",
		},
	},
		allFlags(flags))
}

func TestPanics(t *testing.T) {
	flags := flag.NewFlagSet("test", 0)
	assert.PanicsWithValue(t, `invalid default "a" for int entry prefix.number: strconv.Atoi: parsing "a": invalid syntax`, func() {
		var context struct {
			Number int `default:"a"`
		}
		AddOptionsToSet(flags, &context, "prefix")
	})

	assert.PanicsWithValue(t, `invalid default "10000000000000000000" for int entry prefix.number: strconv.Atoi: parsing "10000000000000000000": value out of range`, func() {
		var context struct {
			Number int `default:"10000000000000000000"`
		}
		AddOptionsToSet(flags, &context, "prefix")
	})

	assert.PanicsWithValue(t, `options parameter without a type - nil?!`, func() {
		AddOptionsToSet(flags, nil, "")
	})

	assert.PanicsWithValue(t, `need a pointer to a struct, got instead: *int`, func() {
		number := 0
		AddOptionsToSet(flags, &number, "")
	})

	assert.PanicsWithValue(t, `struct entry "prefix.number" not exported`, func() {
		var context struct {
			number int
		}
		AddOptionsToSet(flags, &context, "prefix")
	})

	assert.PanicsWithValue(t, `unsupported struct entry type "prefix.somenumber": config.MyInt`, func() {
		type MyInt int
		var context struct {
			SomeNumber MyInt
		}
		AddOptionsToSet(flags, &context, "prefix")
	})
}

type TypesTestCase struct {
	name      string
	copyFlags bool
}

func TestTypes(t *testing.T) {
	testcases := []TypesTestCase{
		{name: "directly"},
		{name: "CopyFlags", copyFlags: true},
	}

	for _, testcase := range testcases {
		testTypes(t, testcase)
	}
}

func testTypes(t *testing.T, testcase TypesTestCase) {
	flags := flag.NewFlagSet("test", 0)
	type Context struct {
		Bool     bool          `default:"true"`
		Duration time.Duration `default:"1ms"`
		Float64  float64       `default:"1.23456789"`
		String   string        `default:"hello world"`
		Int      int           `default:"-1" usage:"some number"`
		Int64    int64         `default:"-1234567890123456789"`
		Uint     uint          `default:"1"`
		Uint64   uint64        `default:"1234567890123456789"`
	}
	var context Context
	require.NotPanics(t, func() {
		AddOptionsToSet(flags, &context, "")
	})

	if testcase.copyFlags {
		original := bytes.Buffer{}
		flags.SetOutput(&original)
		flags.PrintDefaults()

		flags2 := flag.NewFlagSet("test", 0)
		CopyFlags(flags, flags2)
		flags = flags2

		copier := bytes.Buffer{}
		flags.SetOutput(&copier)
		flags.PrintDefaults()
		assert.Equal(t, original.String(), copier.String(), testcase.name+": help messages equal")
		assert.Contains(t, copier.String(), "some number", testcase.name+": copied help message contains defaults")
	}

	require.Equal(t, []simpleFlag{
		{
			name:     "bool",
			defValue: "true",
			isBool:   true,
		},
		{
			name:     "duration",
			defValue: "1ms",
		},
		{
			name:     "float64",
			defValue: "1.23456789",
		},
		{
			name:     "int",
			usage:    "some number",
			defValue: "-1",
		},
		{
			name:     "int64",
			defValue: "-1234567890123456789",
		},
		{
			name:     "string",
			defValue: "hello world",
		},
		{
			name:     "uint",
			defValue: "1",
		},
		{
			name:     "uint64",
			defValue: "1234567890123456789",
		},
	},
		allFlags(flags), testcase.name)
	assert.Equal(t,
		Context{true, time.Millisecond, 1.23456789, "hello world",
			-1, -1234567890123456789, 1, 1234567890123456789,
		},
		context,
		"default values must match")
	require.NoError(t, flags.Parse([]string{
		"-int", "-2",
		"-int64", "-9123456789012345678",
		"-uint", "2",
		"-uint64", "9123456789012345678",
		"-string", "pong",
		"-float64", "-1.23456789",
		"-bool=false",
		"-duration=1s",
	}), testcase.name)
	assert.Equal(t,
		Context{false, time.Second, -1.23456789, "pong",
			-2, -9123456789012345678, 2, 9123456789012345678,
		},
		context,
		testcase.name+": parsed values must match")
}

func allFlags(fs *flag.FlagSet) []simpleFlag {
	var flags []simpleFlag
	fs.VisitAll(func(f *flag.Flag) {
		s := simpleFlag{
			name:     f.Name,
			usage:    f.Usage,
			defValue: f.DefValue,
		}
		type boolFlag interface {
			flag.Value
			IsBoolFlag() bool
		}
		if fv, ok := f.Value.(boolFlag); ok && fv.IsBoolFlag() {
			s.isBool = true
		}
		flags = append(flags, s)
	})
	return flags
}

type simpleFlag struct {
	name     string
	usage    string
	defValue string
	isBool   bool
}