package operations

import (
	"context"
	"errors"
	"strings"
	"testing"

	"orchestra/internal/domain"
	"orchestra/internal/registry"
	"orchestra/internal/review"
	"orchestra/internal/store"
)

type fakePublisher struct {
	pushes    int
	prCalls   int
	remoteSHA string
	pushErr   error
	prErr     error
	pr        domain.ExternalRef
	lastBody  string
}

func (f *fakePublisher) Push(_ context.Context, _, _, sha string) (string, error) {
	f.pushes++
	if f.pushErr != nil {
		return "", f.pushErr
	}
	if f.remoteSHA != "" {
		return f.remoteSHA, nil
	}
	return sha, nil
}

func (f *fakePublisher) EnsurePR(_ context.Context, plan SubmissionPlan) (domain.ExternalRef, error) {
	f.prCalls++
	f.lastBody = plan.PRBody
	if f.prErr != nil {
		return domain.ExternalRef{}, f.prErr
	}
	if f.pr.ID == "" {
		f.pr = domain.ExternalRef{Provider: "gitea:p", ID: "142", URL: "https://git/pulls/142"}
	}
	return f.pr, nil
}

func gate(sha string) domain.GateResult {
	return domain.GateResult{Command: "go test ./...", ExitCode: 0, SHA: sha, Output: "ok"}
}

// reviewed walks a task to a reviewed state at one commit.
func reviewed(t *testing.T, findings ...review.Finding) (*store.Store, string, registry.Project) {
	t.Helper()
	project := registry.Project{ID: "p", QualityGate: "go test ./..."}
	s, id := atImplement(t, project)
	if _, err := EnterReview(s, project, id, evidence(shaA)); err != nil {
		t.Fatal(err)
	}
	if _, err := RecordReview(s, project, id, review.Result{ResultSHA: shaA, Findings: findings}); err != nil {
		t.Fatal(err)
	}
	return s, id, project
}

func head(sha string) HeadResolver {
	return func(context.Context) (string, error) { return sha, nil }
}

func TestSubmissionEligibility(t *testing.T) {
	// Reviewed A, head A, gate A: allowed.
	s, id, project := reviewed(t)
	task, _ := s.Task(id)
	if check := domain.CheckSubmission(task, shaA, gate(shaA)); !check.Eligible {
		t.Fatalf("want eligible, got %v", check.Reasons)
	}

	// The three shas must agree.
	cases := map[string]struct {
		head string
		g    domain.GateResult
	}{
		"head moved past the review": {shaB, gate(shaB)},
		"gate ran on another commit": {shaB, gate(shaA)},
		"failing gate":               {shaA, domain.GateResult{Command: "go test ./...", ExitCode: 1, SHA: shaA}},
		"unanchored head":            {"short", gate("short")},
	}
	for name, c := range cases {
		if check := domain.CheckSubmission(task, c.head, c.g); check.Eligible {
			t.Fatalf("%s: want refusal", name)
		}
	}
	if _, err := PrepareSubmission(s, project, id, shaB, gate(shaB), Notes{}); !errors.Is(err, ErrNotSubmittable) {
		t.Fatalf("want ErrNotSubmittable, got %v", err)
	}

	// Minor findings do not block. Important findings do.
	s, id, project = reviewed(t, finding("f1", review.Minor))
	task, _ = s.Task(id)
	if check := domain.CheckSubmission(task, shaA, gate(shaA)); !check.Eligible {
		t.Fatalf("minor-only: want eligible, got %v", check.Reasons)
	}
	s, id, project = reviewed(t, finding("f1", review.Important))
	task, _ = s.Task(id)
	check := domain.CheckSubmission(task, shaA, gate(shaA))
	if check.Eligible {
		t.Fatal("an important finding must refuse submission")
	}
	if !strings.Contains(strings.Join(check.Reasons, " "), "unresolved blocker or important") {
		t.Fatalf("reasons = %v", check.Reasons)
	}

	// A pending human decision refuses.
	s, id, project = reviewed(t)
	lease(t, s, id)
	if _, err := RequestHumanDecision(s, project, id, request("which behaviour?")); err != nil {
		t.Fatal(err)
	}
	task, _ = s.Task(id)
	if domain.CheckSubmission(task, shaA, gate(shaA)).Eligible {
		t.Fatal("an outstanding question must refuse submission")
	}

	// A project whose path includes plan but sealed none refuses.
	bare, bareID := phaseStore(t)
	if got, _ := bare.Task(bareID); len(got.RequirePhaseArtifacts(project.Phases())) != 2 {
		t.Fatal("missing research and plan should both be reported")
	}
}

func TestSubmissionRecordsExactIdentityAndIsIdempotent(t *testing.T) {
	s, id, project := reviewed(t, finding("f1", review.Minor))
	pub := &fakePublisher{}
	plan, err := PrepareSubmission(s, project, id, shaA, gate(shaA), Notes{
		BehaviouralChanges: []string{"lookups now use the index"},
		Risks:              []string{"index rebuild on first boot"},
		Hotspots:           []string{"internal/attr/attr.go:81-140 concurrency semantics changed"},
	})
	if err != nil {
		t.Fatal(err)
	}
	e, err := ExecuteSubmission(context.Background(), s, plan, pub, head(shaA))
	if err != nil {
		t.Fatal(err)
	}
	if e.Type != domain.EventTaskSubmitted {
		t.Fatalf("event = %+v", e)
	}
	got, _ := s.Task(id)
	if got.State != domain.StateInReview {
		t.Fatalf("state = %s, want in_review", got.State)
	}
	if got.Submission == nil {
		t.Fatal("no submission recorded")
	}
	if got.Submission.ResultSHA != shaA || got.Submission.PR.ID != "142" || got.Submission.ReviewRef == "" || got.Submission.GateRef == "" {
		t.Fatalf("submission = %+v", got.Submission)
	}
	if got.Submission.RemoteRef != "origin/orchestra/"+id {
		t.Fatalf("remote ref = %q", got.Submission.RemoteRef)
	}
	// Submission is not completion.
	if got.State == domain.StateCompleted {
		t.Fatal("submission must not complete the task")
	}

	// The packet is derived, and labels the agent's account as unverified.
	packet, err := s.Artifact(got.Submission.PacketRef)
	if err != nil {
		t.Fatal(err)
	}
	for _, want := range []string{
		"## Goal", "## Acceptance", "## Verification", "`go test ./...` exited 0",
		"independent review of " + shaA, "minor findings, not fixed: 1",
		"lookups now use the index", "index rebuild on first boot",
		"internal/attr/attr.go:81-140", "are not verified",
	} {
		if !strings.Contains(string(packet), want) {
			t.Fatalf("packet missing %q:\n%s", want, packet)
		}
	}

	// Running it again with unchanged state is the same submission.
	plan2, err := PrepareSubmission(s, project, id, shaA, gate(shaA), Notes{})
	if err != nil {
		t.Fatalf("a repeated submission must not be refused: %v", err)
	}
	if plan2.Existing == nil || plan2.Existing.PR.ID != "142" {
		t.Fatalf("the existing submission was not carried into the plan: %+v", plan2.Existing)
	}
	e2, err := ExecuteSubmission(context.Background(), s, plan2, pub, head(shaA))
	if err != nil {
		t.Fatal(err)
	}
	if e2.ID != "" {
		t.Fatal("a second TaskSubmitted was appended for the same commit")
	}
	if pub.prCalls != 2 || pub.pr.ID != "142" {
		t.Fatalf("pr calls=%d id=%s: a retry must refresh one pull request", pub.prCalls, pub.pr.ID)
	}
}

// A forge failure after a successful push must stay retryable.
func TestPRFailureLeavesTaskRetryable(t *testing.T) {
	s, id, project := reviewed(t)
	pub := &fakePublisher{prErr: errors.New("gitea 502")}
	plan, err := PrepareSubmission(s, project, id, shaA, gate(shaA), Notes{})
	if err != nil {
		t.Fatal(err)
	}
	if _, err := ExecuteSubmission(context.Background(), s, plan, pub, head(shaA)); err == nil {
		t.Fatal("expected the forge failure to surface")
	}
	got, _ := s.Task(id)
	if got.State == domain.StateFailed || got.State == domain.StateInReview {
		t.Fatalf("a transport failure changed the lifecycle: %s", got.State)
	}
	if got.Submission != nil {
		t.Fatal("a failed submission was recorded")
	}

	// The retry re-pushes, verifies, and succeeds.
	pub.prErr = nil
	plan, err = PrepareSubmission(s, project, id, shaA, gate(shaA), Notes{})
	if err != nil {
		t.Fatal(err)
	}
	if _, err := ExecuteSubmission(context.Background(), s, plan, pub, head(shaA)); err != nil {
		t.Fatal(err)
	}
	if got, _ := s.Task(id); got.Submission == nil || got.Submission.ResultSHA != shaA {
		t.Fatalf("retry did not record the submission")
	}
	if pub.pushes != 2 {
		t.Fatalf("pushes = %d, the retry must re-verify the remote", pub.pushes)
	}
}

// The remote holding a different commit is a hard refusal.
func TestRemoteMismatchRecordsNothing(t *testing.T) {
	s, id, project := reviewed(t)
	pub := &fakePublisher{remoteSHA: shaB}
	plan, err := PrepareSubmission(s, project, id, shaA, gate(shaA), Notes{})
	if err != nil {
		t.Fatal(err)
	}
	if _, err := ExecuteSubmission(context.Background(), s, plan, pub, head(shaA)); !errors.Is(err, ErrRemoteMismatch) {
		t.Fatalf("want ErrRemoteMismatch, got %v", err)
	}
	if pub.prCalls != 0 {
		t.Fatal("a pull request was opened for an unverified push")
	}
	if got, _ := s.Task(id); got.Submission != nil {
		t.Fatal("a mismatched submission was recorded")
	}
}

// The commit is re-read immediately before the push and again before the
// event, so a tree that moves mid-submission cannot be submitted.
func TestHeadMovingDuringSubmissionRefuses(t *testing.T) {
	s, id, project := reviewed(t)
	plan, err := PrepareSubmission(s, project, id, shaA, gate(shaA), Notes{})
	if err != nil {
		t.Fatal(err)
	}

	pub := &fakePublisher{}
	if _, err := ExecuteSubmission(context.Background(), s, plan, pub, head(shaB)); !errors.Is(err, ErrNotSubmittable) {
		t.Fatalf("want refusal before push, got %v", err)
	}
	if pub.pushes != 0 {
		t.Fatal("pushed a commit that was no longer head")
	}

	// Moves after the push, before the record.
	calls := 0
	moving := func(context.Context) (string, error) {
		calls++
		if calls == 1 {
			return shaA, nil
		}
		return shaB, nil
	}
	if _, err := ExecuteSubmission(context.Background(), s, plan, pub, moving); !errors.Is(err, ErrNotSubmittable) {
		t.Fatalf("want refusal before recording, got %v", err)
	}
	if got, _ := s.Task(id); got.Submission != nil {
		t.Fatal("recorded a submission for a stale commit")
	}
}

// A change after submission means the recorded submission no longer represents
// the current head.
func TestLaterChangeInvalidatesTheSubmission(t *testing.T) {
	s, id, project := reviewed(t)
	plan, err := PrepareSubmission(s, project, id, shaA, gate(shaA), Notes{})
	if err != nil {
		t.Fatal(err)
	}
	if _, err := ExecuteSubmission(context.Background(), s, plan, &fakePublisher{}, head(shaA)); err != nil {
		t.Fatal(err)
	}
	got, _ := s.Task(id)
	if !got.Submitted(shaA) {
		t.Fatal("submission missing for its own commit")
	}
	if got.Submitted(shaB) {
		t.Fatal("a submission of one commit must not cover another")
	}
	if domain.CheckSubmission(got, shaB, gate(shaB)).Eligible {
		t.Fatal("a new commit must not inherit the old review and submission")
	}
}

func TestNotesAreBounded(t *testing.T) {
	s, id, project := reviewed(t)
	long := strings.Repeat("x", 501)
	bad := []Notes{
		{Risks: []string{""}},
		{Risks: []string{long}},
		{Risks: []string{"one\ntwo"}},
		{Hotspots: make([]string, 13)},
	}
	for i, n := range bad {
		if _, err := PrepareSubmission(s, project, id, shaA, gate(shaA), n); !errors.Is(err, domain.ErrInvalid) {
			t.Fatalf("notes %d: want ErrInvalid, got %v", i, err)
		}
	}
}