package tools

import (
	"fmt"
	"strings"
	"testing"
	"time"
)

// foldKey must agree with strings.EqualFold, which is how encoding/json matches.
func TestFoldKeyAgreesWithEqualFold(t *testing.T) {
	pairs := [][2]string{{"branch", "Branch"}, {"sha", "ſha"}, {"k", "K"}, {"ss", "ß"}, {"a", "b"}, {"Σ", "ς"}}
	for _, p := range pairs {
		if got, want := foldKey(p[0]) == foldKey(p[1]), strings.EqualFold(p[0], p[1]); got != want {
			t.Errorf("%q vs %q: foldKey equal=%v, EqualFold=%v", p[0], p[1], got, want)
		}
	}
}

// The duplicate scan is linear in the number of keys: 90k keys (about the
// 1 MiB body cap) must scan well under a second.
func TestRejectAmbiguousKeysScalesLinearly(t *testing.T) {
	var b strings.Builder
	b.WriteString("{")
	for i := 0; i < 90_000; i++ {
		if i > 0 {
			b.WriteString(",")
		}
		fmt.Fprintf(&b, `"k%d":1`, i)
	}
	b.WriteString("}")
	var dst struct {
		Owner string `json:"owner"`
	}
	start := time.Now()
	if err := rejectAmbiguousKeys([]byte(b.String()), &dst); err != nil {
		t.Fatal(err)
	}
	if d := time.Since(start); d > 2*time.Second {
		t.Errorf("scan of 90k keys took %v", d)
	}
}