package jsonv

import (
	"encoding/json"
	"math"
	"testing"
)

func TestStr(t *testing.T) {
	tests := []struct {
		in   any
		want string
	}{
		{nil, ""},
		{"abc", "abc"},
		{float64(42), "42"},
		{float64(13.5), "13.5"},
		{true, "true"},
		{[]any{1}, "[1]"},
	}
	for _, tt := range tests {
		if got := Str(tt.in); got != tt.want {
			t.Errorf("Str(%v) = %q, want %q", tt.in, got, tt.want)
		}
	}
}

// TestStrOnDecodedJSON is the case that matters: userId comes back as a JSON
// number, and formatting it as "42" rather than "4.2e+01" is what makes it
// usable as an identifier in later requests.
func TestStrOnDecodedJSON(t *testing.T) {
	var v map[string]any
	if err := json.Unmarshal([]byte(`{"userId":1234567890}`), &v); err != nil {
		t.Fatal(err)
	}
	if got, want := Str(v["userId"]), "1234567890"; got != want {
		t.Errorf("Str(userId) = %q, want %q", got, want)
	}
}

func TestNum(t *testing.T) {
	tests := []struct {
		in     any
		want   float64
		wantOK bool
	}{
		{float64(82), 82, true},
		{"82", 82, true},
		{" 13.5 ", 13.5, true},
		{true, 1, true},
		{false, 0, true},
		{"", 0, false},
		{"abc", 0, false},
		{nil, 0, false},
		{map[string]any{}, 0, false},
		{[]any{}, 0, false},
	}
	for _, tt := range tests {
		got, ok := Num(tt.in)
		if ok != tt.wantOK || (ok && got != tt.want) {
			t.Errorf("Num(%#v) = (%v, %v), want (%v, %v)", tt.in, got, ok, tt.want, tt.wantOK)
		}
	}
}

func TestNumRejectsNonFinite(t *testing.T) {
	// A NaN or Inf would render as an invalid metric value, so it is better to
	// know which way these go.
	for _, s := range []string{"NaN", "Inf", "+Inf"} {
		if v, ok := Num(s); ok && !math.IsNaN(v) && !math.IsInf(v, 0) {
			t.Errorf("Num(%q) = %v, expected NaN/Inf or a rejection", s, v)
		}
	}
}