package ff_test

import (
	"context"
	"embed"
	"flag"
	"os"
	"testing"
	"time"

	"github.com/peterbourgon/ff/v3"
	"github.com/peterbourgon/ff/v3/ffcli"
	"github.com/peterbourgon/ff/v3/fftest"
)

//go:embed testdata/*.conf
var testdataConfigFS embed.FS

func TestParseBasics(t *testing.T) {
	t.Parallel()

	for _, testcase := range []struct {
		name string
		env  map[string]string
		file string
		args []string
		opts []ff.Option
		want fftest.Vars
	}{
		{
			name: "empty",
			args: []string{},
			want: fftest.Vars{},
		},
		{
			name: "args only",
			args: []string{"-s", "foo", "-i", "123", "-b", "-d", "24m"},
			want: fftest.Vars{S: "foo", I: 123, B: true, D: 24 * time.Minute},
		},
		{
			name: "file only",
			file: "testdata/1.conf",
			want: fftest.Vars{S: "bar", I: 99, B: true, D: time.Hour},
		},
		{
			name: "env only",
			env:  map[string]string{"TEST_PARSE_S": "baz", "TEST_PARSE_F": "0.99", "TEST_PARSE_D": "100s"},
			opts: []ff.Option{ff.WithEnvVarPrefix("TEST_PARSE")},
			want: fftest.Vars{S: "baz", F: 0.99, D: 100 * time.Second},
		},
		{
			name: "file args",
			file: "testdata/2.conf",
			args: []string{"-s", "foo", "-i", "1234"},
			want: fftest.Vars{S: "foo", I: 1234, D: 3 * time.Second},
		},
		{
			name: "env args",
			env:  map[string]string{"TEST_PARSE_S": "should be overridden", "TEST_PARSE_B": "true"},
			args: []string{"-s", "explicit wins", "-i", "7"},
			opts: []ff.Option{ff.WithEnvVarPrefix("TEST_PARSE")},
			want: fftest.Vars{S: "explicit wins", I: 7, B: true},
		},
		{
			name: "file env",
			env:  map[string]string{"TEST_PARSE_S": "env takes priority", "TEST_PARSE_B": "true"},
			file: "testdata/3.conf",
			opts: []ff.Option{ff.WithEnvVarPrefix("TEST_PARSE")},
			want: fftest.Vars{S: "env takes priority", I: 99, B: true, D: 34 * time.Second},
		},
		{
			name: "file env args",
			file: "testdata/4.conf",
			env:  map[string]string{"TEST_PARSE_S": "from env", "TEST_PARSE_I": "300", "TEST_PARSE_F": "0.15", "TEST_PARSE_B": "true"},
			args: []string{"-s", "from arg", "-i", "100"},
			opts: []ff.Option{ff.WithEnvVarPrefix("TEST_PARSE")},
			want: fftest.Vars{S: "from arg", I: 100, F: 0.15, B: true, D: time.Minute},
		},
		{
			name: "repeated args",
			args: []string{"-s", "foo", "-s", "bar", "-d", "1m", "-d", "1h", "-x", "1", "-x", "2", "-x", "3"},
			want: fftest.Vars{S: "bar", D: time.Hour, X: []string{"1", "2", "3"}},
		},
		{
			name: "priority repeats",
			env:  map[string]string{"TEST_PARSE_S": "s.env", "TEST_PARSE_X": "x.env.1"},
			file: "testdata/5.conf",
			args: []string{"-s", "s.arg.1", "-s", "s.arg.2", "-x", "x.arg.1", "-x", "x.arg.2"},
			opts: []ff.Option{ff.WithEnvVarPrefix("TEST_PARSE")},
			want: fftest.Vars{S: "s.arg.2", X: []string{"x.arg.1", "x.arg.2"}}, // highest prio wins and no others are called
		},
		{
			name: "PlainParser solo bool",
			file: "testdata/solo_bool.conf",
			want: fftest.Vars{S: "x", B: true},
		},
		{
			name: "PlainParser string with spaces",
			file: "testdata/spaces.conf",
			want: fftest.Vars{S: "i am the very model of a modern major general"},
		},
		{
			name: "default comma behavior",
			env:  map[string]string{"TEST_PARSE_S": "one,two,three", "TEST_PARSE_X": "one,two,three"},
			opts: []ff.Option{ff.WithEnvVarPrefix("TEST_PARSE")},
			want: fftest.Vars{S: "one,two,three", X: []string{"one,two,three"}},
		},
		{
			name: "WithEnvVarSplit",
			env:  map[string]string{"TEST_PARSE_S": "one,two,three", "TEST_PARSE_X": "one,two,three"},
			opts: []ff.Option{ff.WithEnvVarPrefix("TEST_PARSE"), ff.WithEnvVarSplit(",")},
			want: fftest.Vars{S: "three", X: []string{"one", "two", "three"}},
		},
		{
			name: "WithEnvVars",
			env:  map[string]string{"TEST_PARSE_S": "foo", "S": "bar"},
			opts: []ff.Option{ff.WithEnvVars()},
			want: fftest.Vars{S: "bar"},
		},
		{
			name: "WithIgnoreUndefined env",
			env:  map[string]string{"TEST_PARSE_UNDEFINED": "one", "TEST_PARSE_S": "one"},
			opts: []ff.Option{ff.WithEnvVarPrefix("TEST_PARSE"), ff.WithIgnoreUndefined(true)},
			want: fftest.Vars{S: "one"},
		},
		{
			name: "WithIgnoreUndefined file true",
			file: "testdata/undefined.conf",
			opts: []ff.Option{ff.WithIgnoreUndefined(true)},
			want: fftest.Vars{S: "one"},
		},
		{
			name: "WithIgnoreUndefined file false",
			file: "testdata/undefined.conf",
			opts: []ff.Option{ff.WithIgnoreUndefined(false)},
			want: fftest.Vars{WantParseErrorString: "config file flag"},
		},
		{
			name: "env var split comma whitespace",
			env:  map[string]string{"TEST_PARSE_S": "one, two, three ", "TEST_PARSE_X": "one, two, three "},
			opts: []ff.Option{ff.WithEnvVarPrefix("TEST_PARSE"), ff.WithEnvVarSplit(",")},
			want: fftest.Vars{S: " three ", X: []string{"one", " two", " three "}},
		},
		{
			name: "WithEnvVars",
			env:  map[string]string{"S": "xxx", "F": "9.87"},
			opts: []ff.Option{ff.WithEnvVars()},
			want: fftest.Vars{S: "xxx", F: 9.87},
		},
		{
			name: "WithEnvVarNoPrefix", // make sure alias works
			env:  map[string]string{"S": "xxx", "F": "9.87"},
			opts: []ff.Option{ff.WithEnvVarNoPrefix()},
			want: fftest.Vars{S: "xxx", F: 9.87},
		},
		{
			name: "WithFilesystem testdata/1.conf",
			opts: []ff.Option{ff.WithFilesystem(testdataConfigFS), ff.WithConfigFile("testdata/1.conf"), ff.WithConfigFileParser(ff.PlainParser)},
			want: fftest.Vars{S: "bar", I: 99, B: true, D: 1 * time.Hour},
		},
	} {
		t.Run(testcase.name, func(t *testing.T) {
			if testcase.file != "" {
				testcase.opts = append(testcase.opts, ff.WithConfigFile(testcase.file), ff.WithConfigFileParser(ff.PlainParser))
			}

			if len(testcase.env) > 0 {
				for k, v := range testcase.env {
					defer os.Setenv(k, os.Getenv(k))
					os.Setenv(k, v)
				}
			}

			fs, vars := fftest.Pair()
			vars.ParseError = ff.Parse(fs, testcase.args, testcase.opts...)
			fftest.Compare(t, &testcase.want, vars)
		})
	}
}

func TestParseIssue16(t *testing.T) {
	t.Parallel()

	for _, testcase := range []struct {
		name string
		data string
		want string
	}{
		{
			name: "hash in value",
			data: "s bar#baz",
			want: "bar#baz",
		},
		{
			name: "EOL comment with space",
			data: "s bar # baz",
			want: "bar",
		},
		{
			name: "EOL comment no space",
			data: "s bar #baz",
			want: "bar",
		},
		{
			name: "only comment with space",
			data: "# foo bar\n",
			want: "",
		},
		{
			name: "only comment no space",
			data: "#foo bar\n",
			want: "",
		},
	} {
		t.Run(testcase.name, func(t *testing.T) {
			filename := fftest.TempFile(t, testcase.data)

			fs, vars := fftest.Pair()
			vars.ParseError = ff.Parse(fs, []string{},
				ff.WithConfigFile(filename),
				ff.WithConfigFileParser(ff.PlainParser),
			)

			want := fftest.Vars{S: testcase.want}
			fftest.Compare(t, &want, vars)
		})
	}
}

func TestParseConfigFile(t *testing.T) {
	t.Parallel()

	for _, testcase := range []struct {
		name         string
		missing      bool
		allowMissing bool
		parseError   error
	}{
		{
			name: "has config file",
		},
		{
			name:       "config file missing",
			missing:    true,
			parseError: os.ErrNotExist,
		},
		{
			name:         "config file missing + allow missing",
			missing:      true,
			allowMissing: true,
		},
	} {
		t.Run(testcase.name, func(t *testing.T) {
			filename := "dummy"
			if !testcase.missing {
				filename = fftest.TempFile(t, "")
			}

			options := []ff.Option{ff.WithConfigFile(filename), ff.WithConfigFileParser(ff.PlainParser)}
			if testcase.allowMissing {
				options = append(options, ff.WithAllowMissingConfigFile(true))
			}

			fs, vars := fftest.Pair()
			vars.ParseError = ff.Parse(fs, []string{}, options...)

			want := fftest.Vars{WantParseErrorIs: testcase.parseError}
			fftest.Compare(t, &want, vars)
		})
	}
}

func TestParseConfigFileVia(t *testing.T) {
	t.Parallel()

	var (
		rootFS = flag.NewFlagSet("root", flag.ContinueOnError)
		config = rootFS.String("config-file", "", "")
		i      = rootFS.Int("i", 0, "")
		s      = rootFS.String("s", "", "")
		subFS  = flag.NewFlagSet("subcommand", flag.ContinueOnError)
		d      = subFS.Duration("d", time.Second, "")
		b      = subFS.Bool("b", false, "")
	)

	subCommand := &ffcli.Command{
		Name:    "subcommand",
		FlagSet: subFS,
		Options: []ff.Option{
			ff.WithConfigFileParser(ff.PlainParser),
			ff.WithConfigFileVia(config),
			ff.WithIgnoreUndefined(true),
		},
		Exec: func(ctx context.Context, args []string) error { return nil },
	}

	root := &ffcli.Command{
		Name:    "root",
		FlagSet: rootFS,
		Options: []ff.Option{
			ff.WithConfigFileParser(ff.PlainParser),
			ff.WithConfigFileFlag("config-file"),
			ff.WithIgnoreUndefined(true),
		},
		Exec:        func(ctx context.Context, args []string) error { return nil },
		Subcommands: []*ffcli.Command{subCommand},
	}

	err := root.ParseAndRun(context.Background(), []string{"-config-file", "testdata/1.conf", "subcommand", "-b"})
	if err != nil {
		t.Fatal(err)
	}

	if want, have := time.Hour, *d; want != have {
		t.Errorf("d: want %v, have %v", want, have)
	}
	if want, have := true, *b; want != have {
		t.Errorf("b: want %v, have %v", want, have)
	}
	if want, have := "bar", *s; want != have {
		t.Errorf("s: want %q, have %q", want, have)
	}
	if want, have := 99, *i; want != have {
		t.Errorf("i: want %d, have %d", want, have)
	}
}