package delivery

import (
	"errors"
	"reflect"
	"strings"
	"testing"

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

// ADR 0549 §1, §2: the placement key and file, the value's refusals, its reading as the composition reads a node, what
// a change says, and the catalogue's check of every file.
func TestPlacement(t *testing.T) {
	t.Run("key and file", func(t *testing.T) {
		key, err := PlacementKey("g14")
		if err != nil || key != "placement.g14" {
			t.Fatalf("PlacementKey = %q, %v", key, err)
		}
		if n, err := ParsePlacementKey(key); err != nil || n != "g14" {
			t.Fatalf("ParsePlacementKey = %q, %v", n, err)
		}
		for _, bad := range []string{"want.g14.x", "placement.", "placement.a.b"} {
			if _, err := ParsePlacementKey(bad); err == nil {
				t.Errorf("ParsePlacementKey(%q) took it", bad)
			}
		}
		if _, err := PlacementKey("a.b"); err == nil {
			t.Error("PlacementKey took a dotted node")
		}
		if PlacementBucket != "mesh-delivery-indexer_placement" || PlacementFile("ace") != "placement/ace.json" {
			t.Fatalf("bucket %q, file %q", PlacementBucket, PlacementFile("ace"))
		}
		for p, want := range map[string]string{"placement/ace.json": "ace", "./placement/ace.json": "ace",
			"placement/x/ace.json": "", "modules/ace.json": "", "placement/ace.yaml": ""} {
			if n, ok := PlacementFileNode(p); n != want || ok != (want != "") {
				t.Errorf("PlacementFileNode(%q) = %q, %v", p, n, ok)
			}
		}
	})

	g14 := Placement{Node: "g14", Revision: "abc",
		Decided: NodeDecided{Endpoint: "g14.example:51820", Site: "home", Address: "10.77.0.2", Account: "op", Taken: []string{"zsh"}},
		Modules: []PlacedModule{
			{Module: "zsh"},
			{Module: "app", Ports: map[string]int{"8080": 18080}, Bindings: map[string]Provider{"postgres": {Node: "novox", Module: "postgres"}}},
		},
		Pins:  map[string]Provider{"shell": {Node: "g14", Module: "zsh"}},
		Holds: []Holding{{Claim: "node-shell", Scope: "node", Module: "zsh"}},
	}
	novox := Placement{Node: "novox", Decided: NodeDecided{Hub: true, Address: "10.77.0.1"}, Modules: []PlacedModule{{Module: "postgres", Ports: map[string]int{"5432": 5432}}},
		Holds: []Holding{{Claim: "mesh-store", Scope: "mesh", Module: "postgres"}}}

	t.Run("value", func(t *testing.T) {
		raw, err := EncodePlacement(g14)
		if err != nil {
			t.Fatal(err)
		}
		back, err := DecodePlacement(raw)
		if err != nil || back.V != Version || !SamePlacement(back, g14) {
			t.Fatalf("round trip: %+v, %v", back, err)
		}
		moved := g14
		moved.Revision = "def"
		if !SamePlacement(g14, moved) {
			t.Error("a new revision alone counts as a change")
		}
		if _, err := DecodePlacement([]byte(`{"v":9,"node":"g14","modules":[]}`)); !errors.Is(err, ErrUnknownVersion) {
			t.Errorf("version 9: %v", err)
		}
		for name, bad := range map[string]string{
			"module twice":     `{"v":1,"node":"g14","modules":[{"module":"a"},{"module":"a"}]}`,
			"port not number":  `{"v":1,"node":"g14","modules":[{"module":"a","ports":{"http":80}}]}`,
			"host port zero":   `{"v":1,"node":"g14","modules":[{"module":"a","ports":{"80":0}}]}`,
			"binding no node":  `{"v":1,"node":"g14","modules":[{"module":"a","bindings":{"pg":{"module":"pg"}}}]}`,
			"pin no module":    `{"v":1,"node":"g14","modules":[],"pins":{"pg":{"node":"x"}}}`,
			"hold not placed":  `{"v":1,"node":"g14","modules":[],"holds":[{"claim":"s","module":"a"}]}`,
			"node not a name":  `{"v":1,"node":"g.14","modules":[]}`,
			"value not shaped": `{"v":1,"node":"g14","modules":{}}`,
		} {
			if _, err := DecodePlacement([]byte(bad)); err == nil {
				t.Errorf("%s: taken", name)
			}
		}
	})

	t.Run("as the composition reads it", func(t *testing.T) {
		if got := g14.Assigned(); !reflect.DeepEqual(got, []string{"zsh", "app"}) {
			t.Errorf("Assigned = %v, want the file's order", got)
		}
		if got := g14.ChosenPins(); !reflect.DeepEqual(got, map[string]catalogue.Chosen{"shell": {Node: "g14", Module: "zsh"}}) {
			t.Errorf("ChosenPins = %v", got)
		}
		if got := g14.Bound(); !reflect.DeepEqual(got, map[string]map[string]catalogue.Chosen{"app": {"postgres": {Node: "novox", Module: "postgres"}}}) {
			t.Errorf("Bound = %v", got)
		}
		if got := g14.HostPorts(); !reflect.DeepEqual(got, map[string]map[int]int{"app": {8080: 18080}}) {
			t.Errorf("HostPorts = %v", got)
		}
		if got := g14.Held(); !reflect.DeepEqual(got, []catalogue.Held{{Claim: "node-shell", Scope: "node", Node: "g14", Module: "zsh"}}) {
			t.Errorf("Held = %v", got)
		}
		layered := PlacedModule{Module: "app", HasMesh: true, Layer: map[string]any{"expose": map[string]any{"80": "mesh"}}}
		want := []catalogue.Layer{
			{From: catalogue.MeshWideLayer, Values: map[string]any{}},
			{From: "g14", Values: map[string]any{"mode": "x"}, Placement: map[string]any{"expose": map[string]any{"80": "mesh"}}},
		}
		if got := layered.Layers("g14", map[string]any{"mode": "x"}); !reflect.DeepEqual(got, want) {
			t.Errorf("Layers = %#v, want %#v", got, want)
		}
		if got := (PlacedModule{Module: "a"}).Layers("g14", map[string]any{"k": 1}); len(got) != 1 || got[0].From != "g14" {
			t.Errorf("values alone make the node's layer: %#v", got)
		}
		if got := (PlacedModule{Module: "a", HasLayer: true}).Layers("g14", nil); len(got) != 1 || got[0].Values == nil {
			t.Errorf("an empty layer of the node's own is kept, with empty values: %#v", got)
		}
		if got := (PlacedModule{Module: "a"}).Layers("g14", nil); got != nil {
			t.Errorf("no layer and no value is no layer: %#v", got)
		}
		empty := Placement{Node: "x"}
		if empty.ChosenPins() != nil || empty.Bound() != nil || empty.HostPorts() != nil || len(empty.Held()) != 0 {
			t.Error("an empty placement reads as something")
		}
	})

	t.Run("what a change says", func(t *testing.T) {
		after := g14
		after.Revision = "def"
		after.Modules = []PlacedModule{{Module: "app", Ports: map[string]int{"8080": 18081}}, {Module: "new"}}
		got := ChangeOf(g14, after)
		want := PlacementChange{Node: "g14", Revision: "def", Added: []string{"new"}, Removed: []string{"zsh"}, Changed: []string{"app"}}
		if !reflect.DeepEqual(got, want) {
			t.Errorf("ChangeOf = %+v, want %+v", got, want)
		}
		pinned := g14
		pinned.Pins = nil
		if got := ChangeOf(g14, pinned); !reflect.DeepEqual(got.Changed, []string{"app", "zsh"}) {
			t.Errorf("a pin change changes every module on the node: %+v", got)
		}
		if got := ChangeOf(Placement{}, novox); !reflect.DeepEqual(got.Added, []string{"postgres"}) || got.Node != "novox" {
			t.Errorf("a new node: %+v", got)
		}
	})

	t.Run("the catalogue's check", func(t *testing.T) {
		held := func(m string) bool { return m != "ghost" }
		enrolled := func(n string) bool { return n != "stranger" }
		if r := CheckPlacements(map[string]Placement{"g14": g14, "novox": novox}, held, enrolled); len(r) != 0 {
			t.Fatalf("a sound placement is refused: %v", r)
		}
		clash := g14
		clash.Modules = append([]PlacedModule{{Module: "ghost", Ports: map[string]int{"80": 18080}}}, g14.Modules...)
		clash.Modules[2] = PlacedModule{Module: "app", Ports: map[string]int{"8080": 18080}, Bindings: map[string]Provider{"postgres": {Node: "ace", Module: "postgres"}}}
		clash.Pins = map[string]Provider{"shell": {Node: "g14", Module: "bash"}}
		twice := novox
		twice.Node = "stranger"
		twice.Decided.Address = "10.77.0.2"
		r := CheckPlacements(map[string]Placement{"g14": clash, "novox": novox, "stranger": twice}, held, enrolled)
		for _, want := range []string{"holds no module ghost", "ghost and app are both published on host port 18080",
			"bound to ace/postgres", "pin of shell names g14/bash", "stranger is not an enrolled node",
			"mesh-store, held once for the mesh, is held on novox and stranger",
			"g14 and stranger both have the address 10.77.0.2", "novox, stranger are each placed as it"} {
			found := false
			for _, line := range r {
				found = found || strings.Contains(line, want)
			}
			if !found {
				t.Errorf("no refusal says %q; got %v", want, r)
			}
		}
	})
}