//go:build ignore

// Opens with Go what the locator of datekeys-ts writes, and prints
// src/lib/dkc/testing/locator-interop.json: each recipe of
// src/lib/dkc/testing/locator-interop.ts, written by
// scripts/locator-ts-samples.mjs, with the SHA-256 of each of its files and
// the verdict of Go:
//
//   - locator.Open of the sealed locator with Quicknet, its round and the
//     published release of the round, from the fixtures;
//   - Marshal of the locator that Open gives, which must be the plaintext
//     that TypeScript sealed, and Usable, which must keep every address;
//   - OpenEnvelope of the rest, which must give the .dkc;
//   - RestIn of the rest hidden after a host with Hide, at its offset,
//     which must give the rest again.
//
// A verdict is "ok" or the text of the first thing that failed.
//
// It imports only public packages of the reference implementation, and runs
// in a module of it without changing anything there: an export of the tag
// spec-v0.12, so that no change in progress in datekeys-go is read.
//
//	node scripts/locator-ts-samples.mjs /tmp/samples
//	git -C ../datekeys-go archive spec-v0.12 | tar -x -C /tmp/dkgo
//	(cd /tmp/dkgo && go run .../datekeys-ts/scripts/locator-go-verdicts.go \
//		-source spec-v0.12 -testdata .../datekeys-ts/testdata -samples /tmp/samples > .../locator-interop.json)
package main

import (
	"bytes"
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"errors"
	"flag"
	"fmt"
	"log"
	"os"
	"path/filepath"
	"runtime"
	"sort"
	"strings"

	"g.activething.com/go/DateKeys/locator"
	"g.activething.com/go/DateKeys/profile"
	"g.activething.com/go/DateKeys/provider"
)

type obj = map[string]any

func h(b []byte) string { return hex.EncodeToString(b) }

func check(err error) {
	if err != nil {
		_, file, line, _ := runtime.Caller(1)
		log.Fatalf("%s:%d: %v", filepath.Base(file), line, err)
	}
}

func pattern(n int) []byte {
	b := make([]byte, n)
	for i := range b {
		b[i] = byte(31*i + 7)
	}
	return b
}

func releases(testdata string) map[uint64]provider.Release {
	out := map[uint64]provider.Release{}
	files, err := filepath.Glob(filepath.Join(testdata, "fixtures", "*.json"))
	check(err)
	sort.Strings(files)
	for _, f := range files {
		raw, err := os.ReadFile(f)
		check(err)
		var v struct {
			Release *struct {
				Round     uint64 `json:"round"`
				Signature string `json:"signature"`
			} `json:"release"`
		}
		if err := json.Unmarshal(raw, &v); err != nil || v.Release == nil {
			continue
		}
		sig, err := hex.DecodeString(v.Release.Signature)
		check(err)
		out[v.Release.Round] = provider.Release{Round: v.Release.Round, Signature: sig}
	}
	return out
}

func verdict(r obj, files map[string][]byte, rel map[uint64]provider.Release) error {
	round := uint64(r["round"].(float64))
	release, ok := rel[round]
	if !ok {
		return fmt.Errorf("no release of round %d", round)
	}
	loc, err := locator.Open(profile.Quicknet(), round, release, files["sealed"])
	if err != nil {
		return err
	}
	pt, err := loc.Marshal()
	if err != nil {
		return err
	}
	if !bytes.Equal(pt, files["plaintext"]) {
		return errors.New("another plaintext")
	}
	if len(loc.Usable()) != len(r["addresses"].([]any)) || len(loc.Addresses) != len(loc.Usable()) {
		return errors.New("an address that a reader does not use")
	}
	dkc, err := loc.OpenEnvelope(files["rest"])
	if err != nil {
		return err
	}
	if !bytes.Equal(dkc, files["dkc"]) || !bytes.Equal(dkc, pattern(int(r["dkc_length"].(float64)))) {
		return errors.New("another .dkc")
	}
	file, offset := locator.Hide([]byte("GIF89a, a host of some kind"), files["rest"])
	rest, err := loc.RestIn(append(file, "and more"...), offset)
	if err != nil {
		return err
	}
	if !bytes.Equal(rest, files["rest"]) {
		return errors.New("another rest in the host")
	}
	return nil
}

func main() {
	samples := flag.String("samples", "", "the directory of the samples")
	src := flag.String("source", "", "the commit of datekeys-go")
	testdata := flag.String("testdata", "", "the testdata of this repository")
	flag.Parse()
	if *samples == "" || *src == "" || *testdata == "" {
		log.Fatal("usage: -source <commit> -testdata <dir> -samples <dir>")
	}
	rel := releases(*testdata)
	raw, err := os.ReadFile(filepath.Join(*samples, "samples.json"))
	check(err)
	var doc struct {
		Samples []obj `json:"samples"`
	}
	check(json.Unmarshal(raw, &doc))
	result := []obj{}
	for i, r := range doc.Samples {
		names, err := filepath.Glob(filepath.Join(*samples, fmt.Sprintf("%d.*", i)))
		check(err)
		files := map[string][]byte{}
		digests := obj{}
		for _, n := range names {
			b, err := os.ReadFile(n)
			check(err)
			suffix := strings.TrimPrefix(filepath.Ext(n), ".")
			files[suffix] = b
			s := sha256.Sum256(b)
			digests[suffix] = h(s[:])
		}
		v := "ok"
		if err := verdict(r, files, rel); err != nil {
			v = err.Error()
			log.Printf("%s: %s", r["name"], v)
		}
		r["files"] = digests
		r["verdict"] = v
		result = append(result, r)
	}
	var buf bytes.Buffer
	e := json.NewEncoder(&buf)
	e.SetEscapeHTML(false)
	e.SetIndent("", " ")
	check(e.Encode(obj{"source": *src, "go": runtime.Version(), "description": "What Go makes of the sealed locators and envelopes that datekeys-ts writes from a seed, from the recipes of src/lib/dkc/testing/locator-interop.ts, by scripts/locator-go-verdicts.go: the SHA-256 of each file and the verdict of Go, ok or the text of what failed.", "samples": result}))
	os.Stdout.Write(buf.Bytes())
}