//go:build integration

package integration

import (
	"context"
	"fmt"
	"strings"
	"testing"

	"github.com/google/go-containerregistry/pkg/name"
	"github.com/google/go-containerregistry/pkg/v1/random"

	"atcr.io/internal/testharness"
)

// TestAuthMatrix exercises the authorization matrix that /auth/token plus the
// hold authorizer enforce together. Each row picks an actor (captain / crew
// with write / crew with read-only / stranger / anonymous) and an operation
// (push / pull) and asserts whether the registry round-trip succeeds. We
// reuse a single harness across rows: the actors and repos don't overlap so
// state mutations (e.g. layer records for a push) don't bleed between cases.
//
// The whole matrix runs once per OCI client in `Clients` so we catch
// dialect differences between ggcr (crane) and the OCI working group client
// (oras-go).
func TestAuthMatrix(t *testing.T) {
	h := testharness.New(t)

	// Identities. Each row references one of these — strangers and read-only
	// crew get separate handles so their state stays isolated.
	captain := h.Captain
	crewWriter := h.AddSailor("writer.test")
	crewReader := h.AddSailorWithPermissions("reader.test", []string{"blob:read"})
	stranger := h.AddStranger("stranger.test")

	// Seed a pull target by pushing once as the captain via crane. Both
	// clients pull from the same seed: the manifest exists in the hold
	// regardless of which client reads it.
	seedRef := mustParseRef(t, fmt.Sprintf("%s/%s/seed:tag", h.AppViewHostPort(), captain.Handle()))
	seedImage, err := random.Image(1<<18, 2) // 256KB × 2 layers — keep it small
	if err != nil {
		t.Fatalf("build seed image: %v", err)
	}
	if err := (craneClient{}).Push(t.Context(), t, seedRef.String(), seedImage, h.RegistryCreds(captain)); err != nil {
		t.Fatalf("seed push: %v", err)
	}

	cases := []struct {
		name    string
		creds   testharness.Auth
		op      string // "push" or "pull"
		repoFn  func(client string) string
		wantErr bool
		// errContains lists substrings, any of which is acceptable in the
		// error message. Different OCI clients wrap registry responses
		// with different fidelity:
		//   - crane surfaces the registry response body verbatim
		//     ("authentication required", "blob:write", etc.)
		//   - oras-go drops the /auth/token body and surfaces only the
		//     HTTP status text ("Unauthorized")
		//   - regclient strips response bodies entirely and surfaces
		//     "unauthorized" for any 401/403
		// We accept the broader signals so the matrix can include clients
		// with coarser error wrapping. The strict assertions still apply
		// to crane and oras; regclient gets the "request was denied"
		// signal but loses the reason-string detail.
		errContains []string
	}{
		{
			name:  "captain_push",
			creds: h.RegistryCreds(captain),
			op:    "push",
			repoFn: func(c string) string {
				return fmt.Sprintf("%s/%s/own-%s:tag", h.AppViewHostPort(), captain.Handle(), c)
			},
		},
		{
			name:   "captain_pull",
			creds:  h.RegistryCreds(captain),
			op:     "pull",
			repoFn: func(_ string) string { return seedRef.String() },
		},
		{
			name:  "crew_write_push",
			creds: h.RegistryCreds(crewWriter),
			op:    "push",
			repoFn: func(c string) string {
				return fmt.Sprintf("%s/%s/own-%s:tag", h.AppViewHostPort(), crewWriter.Handle(), c)
			},
		},
		{
			name:   "crew_write_pull",
			creds:  h.RegistryCreds(crewWriter),
			op:     "pull",
			repoFn: func(_ string) string { return seedRef.String() },
		},
		{
			name:  "crew_read_only_push_denied",
			creds: h.RegistryCreds(crewReader),
			op:    "push",
			repoFn: func(c string) string {
				return fmt.Sprintf("%s/%s/own-%s:tag", h.AppViewHostPort(), crewReader.Handle(), c)
			},
			// authgate's checkCrewBlobWrite surfaces "lacks blob:write" through
			// errcode.ErrorCodeDenied. The OCI client wraps it with "DENIED".
			wantErr:     true,
			errContains: []string{"blob:write", "unauthorized"},
		},
		{
			name:   "crew_read_only_pull",
			creds:  h.RegistryCreds(crewReader),
			op:     "pull",
			repoFn: func(_ string) string { return seedRef.String() },
		},
		{
			name:  "stranger_push_denied",
			creds: h.RegistryCreds(stranger),
			op:    "push",
			repoFn: func(c string) string {
				return fmt.Sprintf("%s/%s/own-%s:tag", h.AppViewHostPort(), stranger.Handle(), c)
			},
			// hold_crew_members has no row for stranger → checkCrewBlobWrite
			// returns "crew membership required".
			wantErr:     true,
			errContains: []string{"crew membership required", "unauthorized"},
		},
		{
			name: "stranger_pull",
			// Pull bypasses the membership requirement (it's push-only), so a
			// PDS-known but non-crew identity can still pull from a public
			// hold. This is the credential-helper first-pull case.
			creds:  h.RegistryCreds(stranger),
			op:     "pull",
			repoFn: func(_ string) string { return seedRef.String() },
		},
		{
			name:  "anonymous_push_denied",
			creds: h.AnonCreds(),
			op:    "push",
			// Target a real identity's namespace. A push scope carries a write
			// action, so it is never pull-only and /auth/token challenges it even
			// with anonymous pull enabled. crane surfaces the response body
			// ("authentication required"); oras-go drops the body and surfaces
			// "Unauthorized".
			repoFn: func(c string) string {
				return fmt.Sprintf("%s/%s/anon-push-%s:tag", h.AppViewHostPort(), captain.Handle(), c)
			},
			wantErr:     true,
			errContains: []string{"authentication required", "Unauthorized", "unauthorized"},
		},
		{
			name: "anonymous_pull",
			// The harness hold is public (captain.Public), so a credential-less
			// pull is allowed: /auth/token issues a pull-only token with an empty
			// subject and the hold serves the blobs. Privacy is still the hold's
			// call — a private hold rejects the same request.
			creds:  h.AnonCreds(),
			op:     "pull",
			repoFn: func(_ string) string { return seedRef.String() },
		},
		{
			name: "anonymous_pull_unknown_identity_denied",
			// An unresolvable identity must be a clean NAME_UNKNOWN, not a 500.
			// Anonymous pull makes this path reachable without credentials, and a
			// 5xx would send clients that retry server errors into a retry loop.
			creds: h.AnonCreds(),
			op:    "pull",
			repoFn: func(c string) string {
				return fmt.Sprintf("%s/not-a-real-handle/%s:tag", h.AppViewHostPort(), c)
			},
			wantErr:     true,
			errContains: []string{"not known to registry", "NAME_UNKNOWN", "not found", "404"},
		},
	}

	for _, c := range Clients {
		t.Run(c.Name(), func(t *testing.T) {
			for _, tc := range cases {
				t.Run(tc.name, func(t *testing.T) {
					err := runOp(t.Context(), t, c, tc.op, tc.repoFn(c.Name()), tc.creds)
					if tc.wantErr {
						if err == nil {
							t.Fatalf("%s: expected error, got nil", tc.name)
						}
						if len(tc.errContains) > 0 && !containsAny(err.Error(), tc.errContains) {
							t.Errorf("%s: expected error containing any of %q, got: %v", tc.name, tc.errContains, err)
						}
						return
					}
					if err != nil {
						t.Fatalf("%s: unexpected error: %v", tc.name, err)
					}
				})
			}
		})
	}
}

// TestAuthMatrixPrivateHold covers `public: false` + `allow_all_crew: true`,
// the production configuration: anyone may pull and push, but they must have
// an account. Anonymous gets nothing.
//
// The two captain settings are orthogonal. public decides whether a reader
// with no identity is admitted; allowAllCrew decides whether any authenticated
// user may self-register as crew. With allowAllCrew on, a signed-in stranger
// is auto-enrolled with blob:read+blob:write on first contact (the appview
// reconciles crew membership for pull-only token requests too), so "crew only"
// and "anyone with an account" are the same set. That is the intent, and
// stranger_pull below pins it.
//
// TestAuthMatrix only ever ran against a public hold, so the anonymous-denied
// half of this had no end-to-end coverage at all.
func TestAuthMatrixPrivateHold(t *testing.T) {
	h := testharness.New(t, testharness.WithPrivateHold())

	captain := h.Captain
	crewWriter := h.AddSailor("writer.test")
	crewReader := h.AddSailorWithPermissions("reader.test", []string{"blob:read"})
	stranger := h.AddStranger("stranger.test")

	// Seed as the captain: the owner can always write to their own hold.
	seedRef := mustParseRef(t, fmt.Sprintf("%s/%s/seed:tag", h.AppViewHostPort(), captain.Handle()))
	seedImage, err := random.Image(1<<18, 2)
	if err != nil {
		t.Fatalf("build seed image: %v", err)
	}
	if err := (craneClient{}).Push(t.Context(), t, seedRef.String(), seedImage, h.RegistryCreds(captain)); err != nil {
		t.Fatalf("seed push: %v", err)
	}

	// Denials on a private hold are authorization failures, so accept the
	// signals the various clients surface for a 401/403.
	denied := []string{"unauthorized", "Unauthorized", "authentication required",
		"read access denied", "not a crew member", "denied", "403", "401"}

	cases := []struct {
		name        string
		creds       testharness.Auth
		op          string
		repoFn      func(client string) string
		wantErr     bool
		errContains []string
	}{
		{
			name:   "captain_pull",
			creds:  h.RegistryCreds(captain),
			op:     "pull",
			repoFn: func(_ string) string { return seedRef.String() },
		},
		{
			name: "crew_write_pull",
			// blob:write implies blob:read.
			creds:  h.RegistryCreds(crewWriter),
			op:     "pull",
			repoFn: func(_ string) string { return seedRef.String() },
		},
		{
			name:   "crew_read_only_pull",
			creds:  h.RegistryCreds(crewReader),
			op:     "pull",
			repoFn: func(_ string) string { return seedRef.String() },
		},
		{
			name: "stranger_pull",
			// Allowed, and deliberately so: allow_all_crew means a signed-in
			// stranger self-registers as crew on first contact and is granted
			// blob:read+blob:write. "You need an account" is the rule here,
			// not "the captain must have added you".
			creds:  h.RegistryCreds(stranger),
			op:     "pull",
			repoFn: func(_ string) string { return seedRef.String() },
		},
		{
			name: "anonymous_pull_denied",
			// captain.Public is the only thing that admits an anonymous
			// reader, and it is false here.
			creds:       h.AnonCreds(),
			op:          "pull",
			repoFn:      func(_ string) string { return seedRef.String() },
			wantErr:     true,
			errContains: denied,
		},
		{
			name:  "captain_push",
			creds: h.RegistryCreds(captain),
			op:    "push",
			repoFn: func(c string) string {
				return fmt.Sprintf("%s/%s/priv-%s:tag", h.AppViewHostPort(), captain.Handle(), c)
			},
		},
		{
			name:  "anonymous_push_denied",
			creds: h.AnonCreds(),
			op:    "push",
			repoFn: func(c string) string {
				return fmt.Sprintf("%s/%s/anon-push-%s:tag", h.AppViewHostPort(), captain.Handle(), c)
			},
			wantErr:     true,
			errContains: denied,
		},
	}

	for _, c := range Clients {
		t.Run(c.Name(), func(t *testing.T) {
			for _, tc := range cases {
				t.Run(tc.name, func(t *testing.T) {
					err := runOp(t.Context(), t, c, tc.op, tc.repoFn(c.Name()), tc.creds)
					if tc.wantErr {
						if err == nil {
							t.Fatalf("%s: expected error, got nil", tc.name)
						}
						if len(tc.errContains) > 0 && !containsAny(err.Error(), tc.errContains) {
							t.Errorf("%s: expected error containing any of %q, got: %v", tc.name, tc.errContains, err)
						}
						return
					}
					if err != nil {
						t.Fatalf("%s: unexpected error: %v", tc.name, err)
					}
				})
			}
		})
	}
}

// runOp performs the chosen op against the given ref using the supplied
// client and credentials. Push builds a fresh random image so concurrent or
// subsequent runs don't collide on shared blob digests at the registry; pull
// just resolves the reference, which is enough to exercise the auth path
// even without comparing digests.
func runOp(ctx context.Context, t *testing.T, c Client, op, ref string, creds testharness.Auth) error {
	t.Helper()
	switch op {
	case "push":
		img, err := random.Image(1<<17, 2) // 128KB × 2 layers
		if err != nil {
			return fmt.Errorf("build random image: %w", err)
		}
		return c.Push(ctx, t, ref, img, creds)
	case "pull":
		_, err := c.Pull(ctx, ref, creds)
		return err
	default:
		return fmt.Errorf("unknown op %q", op)
	}
}

func containsAny(s string, subs []string) bool {
	for _, sub := range subs {
		if strings.Contains(s, sub) {
			return true
		}
	}
	return false
}

func mustParseRef(t *testing.T, s string) name.Reference {
	t.Helper()
	r, err := name.ParseReference(s, name.Insecure)
	if err != nil {
		t.Fatalf("parse ref %q: %v", s, err)
	}
	return r
}