package catalogue

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

// A provider and its consumer on ONE machine, which is what ADR 0066's anchor is.
//
// **Every fault in this file is the same shape: the same-node path diverging from the cross-node
// one.** A provider on another machine is walked by the control plane — its served facts are
// re-derived from its manifest with that machine's port assignments and settled with that node's
// settings layers — and only then handed to the consumer. A provider on the consumer's OWN machine
// never passes through that walk, so every step of it had to be repeated here, and each step that
// was not is a promise the co-located arrangement quietly breaks.
//
// 04-ISSUES/038 was the first of them (the port). These are the rest.

// A root certificate, in the shape a certificate authority serves one.
const servedRoot = `-----BEGIN CERTIFICATE-----
MIIBeDCCAR2gAwIBAgIQfake0000000000000000000000
-----END CERTIFICATE-----
`

// stepCA is an internal ACME authority: it answers `acme-ca` from anywhere in the mesh, and what a
// consumer must know is the directory URL and the root to trust. **The root is not knowable when
// the module is written** — it exists only once the CA has been initialised — so the manifest
// declares the key and the operator supplies the value as a setting, which is exactly the shape the
// cross-node path settles and the same-node path did not.
func stepCA() Manifest {
	return Manifest{
		Module: "step-ca", Version: "1",
		Provides: FromAnywhere("acme-ca"),
		Listens:  []Listening{{Port: 9000, Protocol: "tcp", From: FromMesh}},
		Serves: map[string]map[string]any{"acme-ca": {
			"directory": "https://anchor.internal/acme/acme/directory",
			// Declared empty: a manifest is the same on every mesh, and this mesh's root is not.
			"root": "",
		}},
		Resources: []map[string]any{{
			"id": "server", "type": "container", "name": "step-ca", "ports": []any{"9000"},
		}},
	}
}

// routeProxy issues from that authority, so it must be told the root to verify it with.
func routeProxy() Manifest {
	return Manifest{
		Module: "route-proxy", Version: "1",
		Requires: []string{"acme-ca"},
		Provides: FromAnywhere("route"),
		Binds:    map[string]string{"acme-ca": "/var/lib/route-proxy/acme-ca.json"},
		Receives: map[string]string{"route": "/var/lib/route-proxy/routes.json"},
		Resources: []map[string]any{{
			"id": "bundle", "type": "file", "path": "/var/lib/route-proxy/ca.pem", "mode": "0644",
			"content": "${bound:acme-ca:root}",
		}},
	}
}

// A co-located provider's served VALUES reach its consumer, not just its served keys.
//
// The mesh walks a provider on ANOTHER machine and settles what it serves with that node's settings
// layers before offering it (cmd/mesh-controller plan.go, theRestOfTheMesh). A provider on the
// consumer's own machine was never settled at all: resolve.go's servedHere and declaration.go's
// here() both read the manifest and stop there. So a served value the operator supplied — the one
// kind of value a manifest cannot carry, because it is different on every mesh — arrived as the
// manifest's empty default.
//
// The consequence is silent and total: route-proxy wrote an empty CA bundle, fell back to the
// system trust store, could not verify the internal authority, and no certificate was ever issued.
func TestACoLocatedProvidersServedValuesReachItsConsumer(t *testing.T) {
	r, err := Resolve(shelf(stepCA(), routeProxy()),
		[]string{"step-ca", "route-proxy"}, reachable(), World{})
	if err != nil {
		t.Fatal(err)
	}

	// What the operator set on the provider, on this node — the CA's root, which only exists once
	// the CA has been initialised.
	out, err := r.Declaration(Rendering{Settings: SettingsBy{
		"step-ca": {{From: "the operator", Values: map[string]any{"root": servedRoot}}},
	}})
	if err != nil {
		t.Fatal(err)
	}

	bundle := fileNamed(out, "route-proxy.bundle")
	if bundle == nil {
		t.Fatalf("the consumer was given no bundle at all: %v", out)
	}
	if got := bundle["content"]; got != servedRoot {
		t.Errorf("the co-located consumer was not told the root it must trust:\n got %q\nwant %q",
			got, servedRoot)
	}
}

// And the binding file says the same thing, for a consumer that reads the binding rather than a
// substituted placeholder. The two are one fact and must not be able to disagree.
func TestACoLocatedConsumersBindingCarriesTheSettledValues(t *testing.T) {
	r, err := Resolve(shelf(stepCA(), routeProxy()),
		[]string{"step-ca", "route-proxy"}, reachable(), World{})
	if err != nil {
		t.Fatal(err)
	}
	out, err := r.Declaration(Rendering{
		Settings: SettingsBy{
			"step-ca": {{From: "the operator", Values: map[string]any{"root": servedRoot}}},
		},
		// And the machine moved the provider's port while it was at it, so both halves of the
		// cross-node derivation are exercised at once.
		Ports: map[string]map[int]int{"step-ca": {9000: 19000}},
	})
	if err != nil {
		t.Fatal(err)
	}

	binding := fileNamed(out, "route-proxy.bound-acme-ca")
	if binding == nil {
		t.Fatalf("the consumer was given no binding at all: %v", out)
	}
	var said struct {
		Serves map[string]any `json:"serves"`
	}
	if err := json.Unmarshal([]byte(binding["content"].(string)), &said); err != nil {
		t.Fatal(err)
	}
	if said.Serves["root"] != servedRoot {
		t.Errorf("the binding does not carry the settled root: %q", said.Serves["root"])
	}
	if port, _ := asPort(said.Serves["port"]); port != 19000 {
		t.Errorf("the binding does not carry the port the machine publishes: %v", said.Serves["port"])
	}
}

// A provider PULLED IN rather than assigned is settled the same way.
//
// The resolver's same-node need is built during the walk, from whichever modules had been chosen by
// the time the requirement came up — so which path a co-located binding took depended on the order
// a person happened to assign things in. Settling after the closure is known removes that: both
// orders now produce the same file.
func TestACoLocatedProviderIsSettledWhicheverWayItWasPulledIn(t *testing.T) {
	for _, assigned := range [][]string{
		{"step-ca", "route-proxy"},
		{"route-proxy", "step-ca"},
	} {
		r, err := Resolve(shelf(stepCA(), routeProxy()), assigned, reachable(), World{})
		if err != nil {
			t.Fatal(err)
		}
		out, err := r.Declaration(Rendering{Settings: SettingsBy{
			"step-ca": {{From: "the operator", Values: map[string]any{"root": servedRoot}}},
		}})
		if err != nil {
			t.Fatal(err)
		}
		bundle := fileNamed(out, "route-proxy.bundle")
		if bundle == nil || bundle["content"] != servedRoot {
			t.Errorf("assigned %v: the consumer was not told the root", assigned)
		}
	}
}

// A same-node contribution names the port the MACHINE publishes, not the one the module declared.
//
// 04-ISSUES/038 fixed this for what a consumer is TOLD about a provider. This is the other
// direction: what a workload TELLS the provider about itself. gitea declares a bare container port
// 3000, the mesh publishes it as 20000:3000 — and gitea's route contribution still said 3000, so
// the proxy beside it dialled a port nothing listens on and answered 502 for every request.
//
// The redirect uses the CONTRIBUTING module's assignment: the port belongs to the workload, and
// using the provider's map would move it to wherever the proxy happens to be published.
func TestASameNodeContributionNamesThePortTheMachinePublishes(t *testing.T) {
	gitea := Manifest{
		Module: "gitea", Version: "1",
		Listens:     []Listening{{Port: 3000, Protocol: "tcp", From: FromMesh}},
		Contributes: map[string]map[string]any{"route": {"label": "git", "port": 3000}},
		Resources: []map[string]any{{
			"id": "server", "type": "container", "name": "gitea", "ports": []any{"3000"},
		}},
	}
	r, err := Resolve(shelf(gitea, routeProxy(), stepCA()),
		[]string{"gitea", "route-proxy", "step-ca"}, reachable(), World{})
	if err != nil {
		t.Fatal(err)
	}
	out, err := r.Declaration(Rendering{
		// The machine put gitea's 3000 on 20000, and published it that way.
		Ports: map[string]map[int]int{"gitea": {3000: 20000}},
	})
	if err != nil {
		t.Fatal(err)
	}

	// Where the workload is actually published.
	server := fileNamed(out, "gitea.server")
	if published := strings.Join(asStrings(server["ports"]), ","); published != "20000:3000" {
		t.Fatalf("the workload was not published on the assigned port: %v", server["ports"])
	}

	// What the proxy beside it was told to dial: the SAME port.
	routes := fileNamed(out, "route-proxy.received-route")
	if routes == nil {
		t.Fatalf("the proxy was given no routes file at all: %v", out)
	}
	var given struct {
		Given []Contribution `json:"given"`
	}
	if err := json.Unmarshal([]byte(routes["content"].(string)), &given); err != nil {
		t.Fatal(err)
	}
	if len(given.Given) != 1 {
		t.Fatalf("expected one route, got %v", given.Given)
	}
	port, ok := asPort(given.Given[0].Values["port"])
	if !ok || port != 20000 {
		t.Errorf("the proxy was told to dial a port nothing listens on: %v",
			given.Given[0].Values["port"])
	}
}

// A contribution from ANOTHER machine is left exactly as it was.
//
// Its port belongs to that machine's assignment, which this node's map knows nothing about —
// applying this node's map to it would move a remote workload's port to wherever a local module of
// the same name happens to be published, which is worse than the fault being fixed.
func TestAContributionFromAnotherMachineKeepsItsOwnPort(t *testing.T) {
	r, err := Resolve(shelf(routeProxy(), stepCA()),
		[]string{"route-proxy", "step-ca"}, reachable(), World{})
	if err != nil {
		t.Fatal(err)
	}
	out, err := r.Declaration(Rendering{
		// A same-named module on this machine, moved. The grant below is a laptop's, and must not
		// be dragged along with it.
		Ports: map[string]map[int]int{"gitea": {3000: 20000}},
		Grants: []Grant{{
			Provision: "route", Consumer: "laptop", From: "gitea", At: "laptop.internal",
			Values: map[string]any{"name": "git.example", "port": 3000},
		}},
	})
	if err != nil {
		t.Fatal(err)
	}
	routes := fileNamed(out, "route-proxy.received-route")
	var given struct {
		Given []Contribution `json:"given"`
	}
	if err := json.Unmarshal([]byte(routes["content"].(string)), &given); err != nil {
		t.Fatal(err)
	}
	if len(given.Given) != 1 {
		t.Fatalf("expected one route, got %v", given.Given)
	}
	if port, _ := asPort(given.Given[0].Values["port"]); port != 3000 {
		t.Errorf("another machine's contribution was rewritten with this machine's ports: %v",
			given.Given[0].Values["port"])
	}
}

// The cross-node half of the same fault: a grant assembled on the providing machine carries the
// consumer's declared port until the CONSUMER's machine's assignments are applied to it. The
// declaration layer cannot do it — those assignments are not this machine's, which is the line the
// test above holds — so the grant layer is handed them and does it there.
func TestAContributionIsRedirectedToWhereItsOwnMachinePublishedIt(t *testing.T) {
	published := map[int]int{3000: 20000}

	got := AtPublishedPort(map[string]any{"name": "git.example.tld", "port": 3000}, "forge", published)
	if port, _ := asPort(got["port"]); port != 20000 {
		t.Errorf("the proxy would dial a port that machine never published: %v", got["port"])
	}
	if got["name"] != "git.example.tld" {
		t.Errorf("redirecting the port disturbed the rest of the contribution: %v", got)
	}

	// Idempotent, and silent about a port nobody moved: a module that pinned its own mapping has no
	// assignment, and must come back exactly as it was written.
	again := AtPublishedPort(got, "forge", published)
	if port, _ := asPort(again["port"]); port != 20000 {
		t.Errorf("applying it twice moved the port again: %v", again["port"])
	}
	pinned := AtPublishedPort(map[string]any{"port": 9070}, "office", published)
	if port, _ := asPort(pinned["port"]); port != 9070 {
		t.Errorf("a port the mesh never assigned was rewritten: %v", pinned["port"])
	}
}

func asStrings(v any) []string {
	listed, ok := v.([]any)
	if !ok {
		return nil
	}
	out := make([]string, 0, len(listed))
	for _, one := range listed {
		out = append(out, strings.TrimSpace(plainly(one)))
	}
	return out
}