package composer

import (
	"encoding/json"
	"errors"
	"os"
	"reflect"
	"strings"
	"testing"

	"git.novox.be/novox/mesh-sdk/go/catalogue"
	"git.novox.be/novox/mesh-sdk/go/compose"
)

const demo = `{"module": "demo", "version": "1", "claims": [{"name": "node-files"}]}`

// A manifest named by its digest goes on the wire as {"digest": ...}, and Fill puts the bytes the indexer keeps in its
// place; a raw manifest goes as itself.
func TestAManifestIsItsBytesOrItsDigest(t *testing.T) {
	r := Request{V: Version, Cases: []Case{{Name: "change", Manifests: map[string]Manifest{
		"demo": {Digest: "d1"}, "raw": {Raw: json.RawMessage(`{"module":"raw","version":"1"}`)}},
		Kept: map[string]map[string]Manifest{"laptop": {"demo": {Digest: "d1"}}}}}}
	wire, err := json.Marshal(r)
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(string(wire), `"demo":{"digest":"d1"}`) || !strings.Contains(string(wire), `"raw":{"module":"raw","version":"1"}`) {
		t.Fatalf("on the wire: %s", wire)
	}
	back, err := Decode(wire)
	if err != nil {
		t.Fatal(err)
	}
	if _, err := Run(back); !errors.Is(err, ErrUnfilled) {
		t.Fatalf("a digest left unfilled runs: %v", err)
	}
	asked := 0
	if err := Fill(&back, func(d string) ([]byte, error) {
		asked++
		if d != "d1" {
			return nil, errors.New("no such digest")
		}
		return []byte(demo), nil
	}); err != nil {
		t.Fatal(err)
	}
	if asked != 2 || string(back.Cases[0].Manifests["demo"].Raw) != demo || string(back.Cases[0].Kept["laptop"]["demo"].Raw) != demo {
		t.Fatalf("filled %d times: %+v", asked, back.Cases[0])
	}
	bad := Request{V: Version, Cases: []Case{{Name: "c", Manifests: map[string]Manifest{"x": {Digest: "nope"}}}}}
	if err := Fill(&bad, func(string) ([]byte, error) { return nil, errors.New("not there") }); err == nil || !strings.Contains(err.Error(), "nope") {
		t.Fatalf("a digest the indexer does not hold: %v", err)
	}
}

// The input travels as JSON and comes back equal, so the command composes what its caller meant.
func TestTheInputTravelsAsJSON(t *testing.T) {
	in := compose.Input{
		Nodes: []compose.Node{{Name: "anchor", Assigned: []string{"nats"}, Capabilities: map[string]bool{"systemd": true},
			Place:    compose.Place{Endpoint: "anchor.example:51820", Site: "here", Hub: true, Address: "10.77.0.1"},
			Pins:     map[string]catalogue.Chosen{"bus": {Node: "anchor", Module: "nats"}},
			Settings: map[string][]catalogue.Layer{"nats": {{Values: map[string]any{"port": float64(4222)}}}}}},
		Holdings: []catalogue.Held{{Claim: "mesh-broker", Scope: "mesh", Node: "anchor", Module: "nats"}},
		Issued:   []compose.Issued{{Provision: "bus", Consumer: "laptop", ConsumerModule: "x", Provider: "anchor"}},
	}
	raw, err := json.Marshal(Request{V: Version, Input: in})
	if err != nil {
		t.Fatal(err)
	}
	back, err := Decode(raw)
	if err != nil {
		t.Fatal(err)
	}
	if !reflect.DeepEqual(back.Input, in) {
		t.Fatalf("the input came back as\n%+v\nwant\n%+v", back.Input, in)
	}
}

// The seats a node's assigned modules claim are held there when the request says the holdings come from the claims.
func TestHoldingsComeFromTheClaims(t *testing.T) {
	m, err := catalogue.ParseManifest([]byte(demo))
	if err != nil {
		t.Fatal(err)
	}
	got := HoldingsOf(map[string]catalogue.Manifest{"demo": m}, []compose.Node{{Name: "b", Assigned: []string{"demo"}}, {Name: "a", Assigned: []string{"demo"}}})
	if len(got) != 2 || got[0].Node != "a" || got[0].Claim != "node-files" || got[0].Scope != "node" {
		t.Fatalf("holdings = %+v", got)
	}
}

// A request the command cannot run is refused, never answered as a verdict: another version, a case named twice, an
// unknown depth.
func TestARequestItCannotRunIsRefused(t *testing.T) {
	if _, err := Decode([]byte(`{"v": 2}`)); err == nil {
		t.Error("a request of version 2 is read")
	}
	if _, err := Run(Request{V: Version, Cases: []Case{{Name: "a"}, {Name: "a"}}}); err == nil {
		t.Error("a case named twice runs")
	}
	if _, err := Run(Request{V: Version, Depth: "deep"}); err == nil {
		t.Error("an unknown depth runs")
	}
	v, err := Run(Request{V: Version, Cases: []Case{{Name: "only-read", Manifests: map[string]Manifest{"demo": {Raw: json.RawMessage(demo)}}}}})
	if err != nil || len(v.Cases) != 1 || !v.Cases[0].Manifests["demo"].Accepted || v.Cases[0].Machines != nil || v.SDK == "" {
		t.Fatalf("a request with no machines: %+v, %v", v, err)
	}
}

// A manifest whose config value falls back to a predefined key (novox/hq ADR 0348 §7) is read, not refused for the
// list of predefined keys at the catalogue's root that a run is never handed with its manifests: the merge gate judges
// the fallback in the catalogue. xterm's module.json from mesh-catalog at 835bf22b falls back to "font-size"; a group
// touching xterm or pacman failed its composition on this (group check 18df81380db3). A list in the request is the one
// judged against, so a fallback it does not name is still refused.
func TestAManifestFallingBackToAPredefinedKeyIsRead(t *testing.T) {
	raw, err := os.ReadFile("../catalogue/testdata/catalogue-835bf22b-xterm.module.json")
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(string(raw), `"predefined"`) {
		t.Fatal("the fixture names no predefined key")
	}
	r := Request{V: Version, Cases: []Case{{Name: "change", Manifests: map[string]Manifest{"xterm": {Raw: raw}}}}}
	v, err := Run(r)
	if err != nil {
		t.Fatal(err)
	}
	if got := v.Cases[0].Manifests["xterm"]; !got.Accepted {
		t.Fatalf("xterm: %+v, want accepted", got)
	}
	r.Predefined = catalogue.PredefinedList{"something-else": {Type: "string", Description: "x"}}
	if v, err = Run(r); err != nil {
		t.Fatal(err)
	}
	if got := v.Cases[0].Manifests["xterm"]; got.Accepted || !strings.Contains(got.Refused, "not on the list of predefined keys") {
		t.Fatalf("xterm judged against a list without its key: %+v, want refused naming the list", got)
	}
}