package remembering

import (
	"fmt"
	"os"
	"reflect"
	"strings"
)



func showColour() bool {
	return os.Getenv("NO_COLOUR") == ""
}

func testing(message string, body func()) {
	if showColour() {
		fmt.Fprintf(
			os.Stderr,
			"\033[0;33mtesting\033[0m: %s... ",
			message,
		)
		body()
		fmt.Fprintf(os.Stderr, "\033[0;32mOK\033[0m.\n")
	} else {
		fmt.Fprintf(os.Stderr, "testing: %s... ", message)
		body()
		fmt.Fprintf(os.Stderr, "OK.\n")
	}
}

func assertEq(given any, expected any) {
	if !reflect.DeepEqual(given, expected) {
		if showColour() {
			fmt.Fprintf(os.Stderr, "\033[0;31mERR\033[0m.\n")
		} else {
			fmt.Fprintf(os.Stderr, "ERR.\n")
		}
		fmt.Fprintf(os.Stderr, "given != expected\n")
		fmt.Fprintf(os.Stderr, "given:    %#v\n", given)
		fmt.Fprintf(os.Stderr, "expected: %#v\n", expected)
		os.Exit(1)
	}
}



func pick(menu string, command ...string) (int, string, string) {
	out := strings.Builder{}
	errW := strings.Builder{}
	rc := run(envT{
		allArgs: append(
			[]string{"remembering", "-p", "func", "--"},
			command...,
		),
		in:  strings.NewReader(menu),
		out: &out,
		err: &errW,
	})
	return rc, out.String(), errW.String()
}

func profileBytes() string {
	path, err := profilePath("func")
	if err != nil {
		panic(err)
	}
	data, err := os.ReadFile(path)
	if err != nil {
		panic(err)
	}
	return string(data)
}



func MainTest() {
	testing("a session of picks shapes the ranking", func() {
		tmp, err := os.MkdirTemp(
			"", "remembering-functional-",
		)
		assertEq(err, nil)
		defer os.RemoveAll(tmp)
		saved := os.Getenv("XDG_DATA_HOME")
		os.Setenv("XDG_DATA_HOME", tmp)
		defer os.Setenv("XDG_DATA_HOME", saved)

		menu := "a\nb\nc\nd\ne\n"

		rc, out, errW := pick(menu, "grep", "-F", "c")
		assertEq(rc, 0)
		assertEq(out, "c\n")
		assertEq(errW, "")
		assertEq(
			profileBytes(),
			"0 profile a\n"+
				"0 profile b\n"+
				"1 profile c\n"+
				"0 profile d\n"+
				"0 profile e\n",
		)

		// the learnt pick now ranks first
		rc, out, errW = pick(menu, "head", "-n1")
		assertEq(rc, 0)
		assertEq(out, "c\n")
		assertEq(errW, "")
		assertEq(
			profileBytes(),
			"0 profile a\n"+
				"0 profile b\n"+
				"2 profile c\n"+
				"0 profile d\n"+
				"0 profile e\n",
		)

		// a cancelled menu forwards the status and
		// learns nothing
		rc, out, _ = pick(menu, "sh", "-c", "exit 3")
		assertEq(rc, 3)
		assertEq(out, "")
		assertEq(
			strings.Contains(
				profileBytes(), "2 profile c",
			),
			true,
		)
	})
}