package mcfg

import (
	"bytes"
	"context"
	"strings"
	. "testing"
	"time"

	"github.com/mediocregopher/mediocre-go-lib/mrand"
	"github.com/mediocregopher/mediocre-go-lib/mtest/massert"
	"github.com/mediocregopher/mediocre-go-lib/mtest/mchk"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestSourceCLIHelp(t *T) {
	ctx := context.Background()
	ctx, _ = WithInt(ctx, "foo", 5, "Test int param  ") // trailing space should be trimmed
	ctx, _ = WithBool(ctx, "bar", "Test bool param.")
	ctx, _ = WithString(ctx, "baz", "baz", "Test string param")
	ctx, _ = WithRequiredString(ctx, "baz2", "")
	ctx, _ = WithRequiredString(ctx, "baz3", "")
	src := SourceCLI{}

	buf := new(bytes.Buffer)
	pM, err := src.cliParams(collectParams(ctx))
	require.NoError(t, err)
	SourceCLI{}.printHelp(buf, pM)

	exp := `
--baz2 (Required)

--baz3 (Required)

--bar (Flag)
	Test bool param.

--baz (Default: "baz")
	Test string param.

--foo (Default: 5)
	Test int param.

`
	assert.Equal(t, exp, buf.String())
}

func TestSourceCLI(t *T) {
	type state struct {
		srcCommonState
		SourceCLI
	}

	type params struct {
		srcCommonParams
		nonBoolWEq bool // use equal sign when setting value
	}

	chk := mchk.Checker{
		Init: func() mchk.State {
			var s state
			s.srcCommonState = newSrcCommonState()
			s.SourceCLI.Args = make([]string, 0, 16)
			return s
		},
		Next: func(ss mchk.State) mchk.Action {
			s := ss.(state)
			var p params
			p.srcCommonParams = s.srcCommonState.next()
			// if the param is a bool or unset this won't get used, but w/e
			p.nonBoolWEq = mrand.Intn(2) == 0
			return mchk.Action{Params: p}
		},
		Apply: func(ss mchk.State, a mchk.Action) (mchk.State, error) {
			s := ss.(state)
			p := a.Params.(params)

			s.srcCommonState = s.srcCommonState.applyCtxAndPV(p.srcCommonParams)
			if !p.unset {
				arg := cliKeyPrefix
				if len(p.path) > 0 {
					arg += strings.Join(p.path, cliKeyJoin) + cliKeyJoin
				}
				arg += p.name
				if !p.isBool {
					if p.nonBoolWEq {
						arg += "="
					} else {
						s.SourceCLI.Args = append(s.SourceCLI.Args, arg)
						arg = ""
					}
					arg += p.nonBoolVal
				}
				s.SourceCLI.Args = append(s.SourceCLI.Args, arg)
			}

			err := s.srcCommonState.assert(s.SourceCLI)
			return s, err
		},
	}

	if err := chk.RunFor(2 * time.Second); err != nil {
		t.Fatal(err)
	}
}

func TestSourceCLITailCallback(t *T) {
	ctx := context.Background()
	ctx, _ = WithInt(ctx, "foo", 5, "")
	ctx, _ = WithBool(ctx, "bar", "")

	var tail []string
	src := SourceCLI{TailCallback: func(gotTail []string) {
		tail = gotTail
	}}

	type testCase struct {
		args    []string
		expTail []string
	}

	cases := []testCase{
		{
			args:    []string{"--foo", "5"},
			expTail: []string{},
		},
		{
			args:    []string{"--foo", "5", "a", "b", "c"},
			expTail: []string{"a", "b", "c"},
		},
		{
			args:    []string{"--foo=5", "a", "b", "c"},
			expTail: []string{"a", "b", "c"},
		},
		{
			args:    []string{"--foo", "5", "--bar"},
			expTail: []string{},
		},
		{
			args:    []string{"--foo", "5", "--bar", "a", "b", "c"},
			expTail: []string{"a", "b", "c"},
		},
	}

	for _, tc := range cases {
		tail = []string{}
		src.Args = tc.args
		err := Populate(ctx, src)
		massert.Require(t, massert.Comment(massert.All(
			massert.Nil(err),
			massert.Equal(tc.expTail, tail),
		), "tc: %#v", tc))
	}
}