package main

import (
	"archive/tar"
	"archive/zip"
	"bytes"
	"compress/gzip"
	"crypto/sha256"
	"encoding/base64"
	"encoding/hex"
	"encoding/json"
	"io"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"strings"
	"sync"
	"testing"
	"time"

	"git.novox.be/novox/mesh-contracts/health-and-repair/go/clients/meshconditionsclient"
	"gitea/internal/forgehttp"
	"gitea/internal/packageseats"
)

func tarball(t *testing.T, manifest string) []byte {
	var b bytes.Buffer
	gz := gzip.NewWriter(&b)
	tw := tar.NewWriter(gz)
	_ = tw.WriteHeader(&tar.Header{Name: "package/package.json", Mode: 0o644, Size: int64(len(manifest))})
	_, _ = tw.Write([]byte(manifest))
	_ = tw.Close()
	_ = gz.Close()
	return b.Bytes()
}

func moduleZip(t *testing.T, prefix string) []byte {
	var b bytes.Buffer
	z := zip.NewWriter(&b)
	w, _ := z.Create(prefix + "/go.mod")
	_, _ = w.Write([]byte("module x\n"))
	_ = z.Close()
	return b.Bytes()
}

func sha(b []byte) string { s := sha256.Sum256(b); return hex.EncodeToString(s[:]) }

// registry is the forge's package registry: what was uploaded, by path, and what the files API answers.
type registry struct {
	mu       sync.Mutex
	uploaded map[string][]byte // "npm <name>" or "go"
	held     map[string][]byte // "<type>/<name>/<version>" -> file
	deleted  []string
}

func (g *registry) handle(w http.ResponseWriter, r *http.Request) {
	g.mu.Lock()
	defer g.mu.Unlock()
	body, _ := io.ReadAll(r.Body)
	p := r.URL.EscapedPath()
	// Reads come as the tools' account (read:package), writes as the packages account (write:package), never the admin.
	want := "token reader"
	if r.Method != http.MethodGet {
		want = "token writer"
	}
	if got := r.Header.Get("Authorization"); got == "token stale" {
		http.Error(w, "unauthorized", http.StatusUnauthorized)
		return
	} else if got != want {
		http.Error(w, r.Method+" "+p+" came as "+got+", not "+want, http.StatusForbidden)
		return
	}
	switch {
	case r.Method == http.MethodPut && p == "/api/packages/acme/go/upload":
		if r.Header.Get("Content-Type") != "application/zip" {
			http.Error(w, "not a zip", 400)
			return
		}
		g.uploaded["go"] = body
		w.WriteHeader(http.StatusCreated)
	case r.Method == http.MethodPut && strings.HasPrefix(p, "/api/packages/acme/npm/"):
		g.uploaded["npm "+strings.TrimPrefix(p, "/api/packages/acme/npm/")] = body
		w.WriteHeader(http.StatusCreated)
	case strings.HasPrefix(p, "/api/v1/packages/acme/") && strings.HasSuffix(p, "/files"):
		f, ok := g.held[strings.TrimSuffix(strings.TrimPrefix(r.URL.Path, "/api/v1/packages/acme/"), "/files")]
		if !ok {
			http.NotFound(w, r)
			return
		}
		_ = json.NewEncoder(w).Encode([]map[string]any{{"sha256": sha(f), "size": len(f)}})
	case r.Method == http.MethodGet && p == "/api/v1/packages/acme":
		var out []map[string]any
		for k := range g.held {
			parts := strings.Split(k, "/")
			if parts[0] == r.URL.Query().Get("type") {
				out = append(out, map[string]any{"name": strings.Join(parts[1:len(parts)-1], "/"), "version": parts[len(parts)-1], "created_at": time.Unix(int64(len(parts[len(parts)-1])), 0)})
			}
		}
		_ = json.NewEncoder(w).Encode(out)
	case r.Method == http.MethodDelete:
		g.deleted = append(g.deleted, strings.TrimPrefix(p, "/api/v1/packages/acme/"))
		w.WriteHeader(http.StatusNoContent)
	default:
		http.Error(w, "unexpected "+r.Method+" "+p, 500)
	}
}

// **The package seats store into the forge's package registry** (design 51 *Publishing*): an npm package goes up as
// npm's publish sends it, its package.json from the tarball and its tag as its dist-tag; a Go module's zip goes up to
// the Go upload, its module path read from the zip; held, versions and remove read and delete through the forge's
// package API, a Go version with Go's leading v.
func TestThePackageSeatsStoreIntoTheForge(t *testing.T) {
	g := &registry{uploaded: map[string][]byte{}, held: map[string][]byte{}}
	srv := httptest.NewServer(http.HandlerFunc(g.handle))
	defer srv.Close()
	dir := t.TempDir()
	kept := func(name, token, line string) string {
		file := filepath.Join(dir, name)
		_ = os.WriteFile(file, []byte(token+"\n"), 0o600)
		_ = os.WriteFile(file+".scopes", []byte(line+"\n"), 0o600)
		return file
	}
	reader := forgehttp.Client{URL: srv.URL, TokenFile: kept("token", "reader", "read:package,read:user for mesh-tools"), Account: "mesh-tools"}
	writer := forgehttp.Client{URL: srv.URL, TokenFile: kept("packages-token", "writer", "write:package for mesh-packages"), Account: "mesh-packages"}
	forge := &Forge{Client: reader, Writer: &writer, Owner: "acme"}
	if _, err := (seatStore{forge: func() (*Forge, error) { return &Forge{Client: reader, Owner: "acme"}, nil }}).Put(packageseats.GoSeat, packageseats.Publish{}, nil); err == nil ||
		!strings.Contains(err.Error(), "write side") {
		t.Errorf("a forge handed no write side wrote: %v", err)
	}
	s := seatStore{forge: func() (*Forge, error) { return forge, nil }}
	// The forge refuses the write side's token: the finding the TypeScript bundle renews on is raised under its key,
	// and the next write the forge takes clears it (no timer looks at the token).
	var refused []bool
	forge.Refused = func(raised bool) { refused = append(refused, raised) }
	if k := meshconditionsclient.Key(meshconditionsclient.ScopeSeat, packageseats.Self, PackagesTokenRefused+".write"); k != PackagesTokenRefusedKey {
		t.Errorf("the refusal's key is %s, the watcher watches %s", k, PackagesTokenRefusedKey)
	}
	_ = os.WriteFile(writer.TokenFile, []byte("stale\n"), 0o600)
	if _, err := s.Put(packageseats.GoSeat, packageseats.Publish{Version: "0.1.15"}, moduleZip(t, "git.example/acme/sdk@v0.1.15")); err == nil ||
		len(refused) != 1 || !refused[0] {
		t.Errorf("a write the forge refused with 401 raised no finding: %v %v", err, refused)
	}
	_ = os.WriteFile(writer.TokenFile, []byte("writer\n"), 0o600)

	tgz := tarball(t, `{"name":"@acme/contracts","version":"0.1.15-feat-x.2","main":"index.js"}`)
	p := packageseats.Publish{Name: "@acme/contracts", Version: "0.1.15-feat-x.2", Tag: "feat-x", Kind: packageseats.KindPackage, Digest: "sha256:" + sha(tgz)}
	if module, err := s.Put(packageseats.NpmSeat, p, tgz); err != nil || module != "" {
		t.Fatalf("npm put: %q, %v", module, err)
	}
	var doc struct {
		DistTags    map[string]string `json:"dist-tags"`
		Versions    map[string]map[string]any
		Attachments map[string]struct{ Data string } `json:"_attachments"`
	}
	if err := json.Unmarshal(g.uploaded["npm @acme%2Fcontracts"], &doc); err != nil {
		t.Fatalf("npm's publish body %v: %s", err, g.uploaded)
	}
	att := doc.Attachments["contracts-0.1.15-feat-x.2.tgz"].Data
	if doc.DistTags["feat-x"] != "0.1.15-feat-x.2" || doc.DistTags["latest"] != "" || doc.Versions["0.1.15-feat-x.2"]["main"] != "index.js" ||
		att != base64.StdEncoding.EncodeToString(tgz) {
		t.Errorf("npm's publish body: %+v", doc)
	}
	p.Name = "@acme/other"
	if _, err := s.Put(packageseats.NpmSeat, p, tgz); err == nil || !strings.Contains(err.Error(), "not @acme/other") {
		t.Errorf("a tarball of another package was uploaded: %v", err)
	}

	zipped := moduleZip(t, "git.example/acme/sdk@v0.1.15")
	gp := packageseats.Publish{Name: "git.example/acme/sdk", Version: "0.1.15", Kind: packageseats.KindPackage, Digest: "sha256:" + sha(zipped)}
	if module, err := s.Put(packageseats.GoSeat, gp, zipped); err != nil || module != "git.example/acme/sdk" || !bytes.Equal(g.uploaded["go"], zipped) {
		t.Fatalf("go put: %q, %v", module, err)
	}
	gp.Version = "0.1.16"
	if _, err := s.Put(packageseats.GoSeat, gp, zipped); err == nil {
		t.Error("a zip of another version was uploaded")
	}

	g.held["go/git.example/acme/sdk/v0.1.15"] = zipped
	if d, ok, err := s.Held(packageseats.GoSeat, "git.example/acme/sdk", "0.1.15"); err != nil || !ok || d != "sha256:"+sha(zipped) {
		t.Errorf("held: %s %v %v", d, ok, err)
	}
	if _, ok, err := s.Held(packageseats.NpmSeat, "x", "0.1.0"); ok || err != nil {
		t.Errorf("a version the forge does not hold: %v %v", ok, err)
	}
	g.held["go/git.example/acme/sdk/v0.1.9"] = zipped
	if v, err := s.Versions(packageseats.GoSeat, "git.example/acme/sdk"); err != nil || len(v) != 2 || v[0].Version != "0.1.15" {
		t.Errorf("versions: %+v %v", v, err)
	}
	if err := s.Remove(packageseats.GoSeat, "git.example/acme/sdk", "0.1.15-feat.1"); err != nil || len(g.deleted) != 1 ||
		g.deleted[0] != "go/git.example%2Facme%2Fsdk/v0.1.15-feat.1" {
		t.Errorf("remove: %v %v", err, g.deleted)
	}
	if len(refused) < 2 || refused[len(refused)-1] {
		t.Errorf("a write the forge took after the refusal did not clear it: %v", refused)
	}
}