package main

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

	"github.com/novox/mesh-controller/internal/catalogue"
	"github.com/novox/mesh-controller/internal/inventory"
	"github.com/novox/mesh-controller/internal/link"
)

// A delivery group's gate is the composed check's, and its members' own checks run their repository's check alone
// (novox/hq ADR 0403 clauses 1 and 7). Pure: no store, no bus.

// A member of a group whose line says composed_gate is a composed member; one whose group says nothing of it (an older
// mesh-delivery), one of a group of a single pull request and a lone pull request are not.
func TestAMemberOfAComposedGroupIsKnownByTheGroupsLine(t *testing.T) {
	two := func(composed bool) groupsLine {
		l := group("feat/x", member("novox/mesh-host", 114, headHost, "main", true), member("novox/mesh-controller", 346, headController, "main", true))
		l.ComposedGate = composed
		return l
	}
	p := link.PullUpdated{Owner: "novox", Repo: "mesh-host", Number: 114, Base: "main", Head: "feat/x", Commit: headHost}
	recheck := link.PullUpdated{Owner: "novox", Repo: "mesh-host", Number: 114, Base: "main", Commit: headHost}
	for name, c := range map[string]struct {
		p     link.PullUpdated
		lines []groupsLine
		want  bool
	}{
		"composed":                 {p, []groupsLine{two(true)}, true},
		"a recheck, by its number": {recheck, []groupsLine{two(true)}, true},
		"an older mesh-delivery":   {p, []groupsLine{two(false)}, false},
		"another group":            {p, []groupsLine{group("feat/y", member("novox/mesh-host", 1, headHost, "main", true))}, false},
		"no group":                 {p, nil, false},
	} {
		if got := composedMember(c.p, c.lines); got != c.want {
			t.Errorf("%s: composed %v, want %v", name, got, c.want)
		}
	}
	alone := group("feat/x", member("novox/mesh-host", 114, headHost, "main", true))
	alone.ComposedGate = true
	if composedMember(p, []groupsLine{alone}) {
		t.Error("a group of a single pull request is composed")
	}
}

// A composed member's verdict never says its gate passed: the gate layer, and the verdict that is the gate's, read
// "composed"; a failure or an error stays what it was.
func TestAComposedMembersVerdictHasNoPassingGate(t *testing.T) {
	asked := &link.CheckRequest{Owner: "novox", Repo: "mesh-host", Number: 114, Composed: true}
	pass := link.BuildResult{ID: "b", Ref: headHost, Checked: asked, Check: &link.CheckOutcome{Verdict: "pass", Summary: "no module touched",
		Gate: &link.CheckLayer{Verdict: "pass", Summary: "no module touched"}, RepoCheck: &link.CheckLayer{Verdict: "pass", Summary: "ok"}}}
	c := checkedOf(pass)
	if c.Gate == nil || c.Gate.Verdict != "composed" || c.Verdict != "composed" || c.RepoCheck == nil || c.RepoCheck.Verdict != "pass" {
		t.Fatalf("the member's verdict says %+v gate %+v", c, c.Gate)
	}
	asked.Composed = false
	if c := checkedOf(pass); c.Gate.Verdict != "pass" || c.Verdict != "pass" {
		t.Fatalf("a member of no composed group has its own gate: %+v", c.Gate)
	}
	asked.Composed = true
	failing := pass
	failing.Check = &link.CheckOutcome{Verdict: "fail", Summary: "conflict", Gate: &link.CheckLayer{Verdict: "fail", Summary: "conflict"},
		RepoCheck: &link.CheckLayer{Verdict: "fail", Summary: "conflict"}}
	if c := checkedOf(failing); c.Gate.Verdict != "fail" || c.Verdict != "fail" {
		t.Fatalf("a failure was read as composed: %+v", c.Gate)
	}
	broken := link.BuildResult{ID: "b", Ref: headHost, Checked: asked, Failed: "the facts snapshot cannot be read"}
	if c := checkedOf(broken); c.Verdict != "error" || c.Gate.Verdict != "error" {
		t.Fatalf("an error was read as composed: %+v", c)
	}
}

// The composed verdict on the bus carries every member, each with its trunk commit, for the forge's holder to set each
// member's mesh/merge-gate from it.
func TestTheComposedVerdictCarriesEveryMember(t *testing.T) {
	asked := &link.CheckRequest{Owner: "novox", Repo: "mesh-host", Number: 114, Group: "feat/x",
		Members: []link.GroupMember{{Owner: "novox", Repo: "mesh-controller", Number: 346, Ref: headController}}}
	c := checkedOf(link.BuildResult{ID: "g", Ref: headHost, Checked: asked, Check: &link.CheckOutcome{Verdict: "pass", Summary: "ok",
		Trunk: "aaaaaaaaaaaa", Members: []link.CheckedMember{{Owner: "novox", Repo: "mesh-controller", Commit: headController[:12], Trunk: "bbbbbbbbbbbb"}}}})
	body, _ := json.Marshal(c)
	for _, want := range []string{`"group":"feat/x"`, `"members":[{"owner":"novox","repo":"mesh-host","number":114,"commit":"` + headHost + `","trunk":"aaaaaaaaaaaa"}`,
		`{"owner":"novox","repo":"mesh-controller","number":346,"commit":"` + headController + `","trunk":"bbbbbbbbbbbb"}`} {
		if !strings.Contains(string(body), want) {
			t.Fatalf("the composed verdict lacks %s:\n%s", want, body)
		}
	}
}

// Members whose manifests order their modules in a cycle fail the composed check, naming every module and edge, and no
// ask is made of the build seat.
func TestAGroupInACycleFailsItsComposedCheckWithoutABuild(t *testing.T) {
	members := []orderMember{
		{ID: "novox/x@" + headHost[:12], Repository: "novox/x", Base: "main", Head: headHost, Number: 7, Paths: []string{"module.json"}},
		{ID: "novox/y@" + headController[:12], Repository: "novox/y", Base: "main", Head: headController, Number: 9, Paths: []string{"module.json"}},
	}
	reach := map[string]orderReach{members[0].ID: {Moved: []string{"mx"}}, members[1].ID: {Moved: []string{"my"}}}
	was, wasParent := manifestAt, parentOf
	t.Cleanup(func() { manifestAt, parentOf = was, wasParent })
	parentOf = func(context.Context, string, string, string) (string, error) { return "", nil }
	manifestAt = func(_ context.Context, _, repo, _, ref string) (catalogue.Manifest, bool, error) {
		if ref == "main" {
			return catalogue.Manifest{}, false, nil // what the pull requests merge into holds no such manifest
		}
		if repo == "x" {
			return catalogue.Manifest{Module: "mx", DefinesSeats: []catalogue.SeatDeclaration{{Name: "s", Serves: []catalogue.Verb{{Name: "a"}}}},
				Invokes: []string{"seat:s.b"}}, true, nil
		}
		return catalogue.Manifest{Module: "my", DefinesSeats: []catalogue.SeatDeclaration{{Name: "s", Serves: []catalogue.Verb{{Name: "b"}}}},
			Invokes: []string{"seat:s.a"}}, true, nil
	}
	c, cyclic, err := cycleVerdict(context.Background(), "feat/cycle", members, reach, []inventory.Edge(nil), nil)
	if err != nil || !cyclic {
		t.Fatalf("no cycle found: %v", err)
	}
	if c.Verdict != "fail" || c.Group != "feat/cycle" || len(c.Members) != 2 || c.Gate == nil || c.Gate.Verdict != "fail" {
		t.Fatalf("the verdict is %+v", c)
	}
	for _, w := range []string{"mx", "my", "s.a", "s.b"} {
		if !strings.Contains(c.Summary, w) {
			t.Errorf("the cycle does not name %s: %s", w, c.Summary)
		}
	}
	// Members with no edge between them are no cycle.
	manifestsReadMu.Lock()
	clear(manifestsRead)
	manifestsReadMu.Unlock()
	manifestAt = func(context.Context, string, string, string, string) (catalogue.Manifest, bool, error) {
		return catalogue.Manifest{}, false, nil
	}
	if _, cyclic, err := cycleVerdict(context.Background(), "feat/cycle", members, reach, nil, nil); err != nil || cyclic {
		t.Fatalf("a cycle where there is none: %v %v", cyclic, err)
	}
}