package operations

import (
	"encoding/json"
	"errors"
	"testing"
	"time"

	"orchestra/internal/authz"
	"orchestra/internal/domain"
	"orchestra/internal/registry"
	"orchestra/internal/store"
	"orchestra/internal/workphase"
)

func phaseStore(t *testing.T) (*store.Store, string) {
	t.Helper()
	s, err := store.Open(t.TempDir())
	if err != nil {
		t.Fatal(err)
	}
	b, _ := json.Marshal(map[string]any{"source": "gitea", "external_id": "381", "project": "p"})
	id := domain.NewID()
	if err := s.Append(domain.Event{ID: domain.NewID(), Type: "TaskCreated", TaskID: id, Version: 1, Payload: b, Surface: string(authz.System)}); err != nil {
		t.Fatal(err)
	}
	return s, id
}

// lease gives the task an owning session. A question or a phase change comes
// from a live session, so a test that skips the lease is exercising a state no
// agent can be in.
func lease(t *testing.T, s *store.Store, id string) {
	t.Helper()
	if _, err := s.Lease(id, "h1", time.Hour); err != nil {
		t.Fatal(err)
	}
}

func sealed(t *testing.T, v interface{ Validate() error }) []byte {
	t.Helper()
	b, err := workphase.Encode(v)
	if err != nil {
		t.Fatal(err)
	}
	return b
}

var research = workphase.Research{Findings: []workphase.Finding{{Claim: "runs per figure", Evidence: "attr.go:88"}}}
var plan = workphase.Plan{Changes: []workphase.Change{{Target: "attr.go", Intent: "aggregate per person"}}}

func TestFullPhasePathSealsEachArtifact(t *testing.T) {
	s, id := phaseStore(t)
	project := registry.Project{ID: "p"}

	// frame -> research needs no artifact: framing produces none.
	if _, err := AdvanceWorkPhase(s, project, id, nil); err != nil {
		t.Fatal(err)
	}
	if got, _ := s.Task(id); got.WorkPhase != domain.WorkPhaseResearch {
		t.Fatalf("phase = %q", got.WorkPhase)
	}

	// research -> plan must seal the research.
	if _, err := AdvanceWorkPhase(s, project, id, nil); !errors.Is(err, domain.ErrInvalid) {
		t.Fatalf("leaving research without an artifact must fail, got %v", err)
	}
	if _, err := AdvanceWorkPhase(s, project, id, []byte(`{"findings":[]}`)); err == nil {
		t.Fatal("an invalid research artifact must be rejected")
	}
	if _, err := AdvanceWorkPhase(s, project, id, sealed(t, research)); err != nil {
		t.Fatal(err)
	}
	got, _ := s.Task(id)
	if got.WorkPhase != domain.WorkPhasePlan || got.ResearchRef == "" {
		t.Fatalf("task = %+v", got)
	}

	// plan -> implement must seal the plan, and must not overwrite the
	// research ref.
	researchRef := got.ResearchRef
	if _, err := AdvanceWorkPhase(s, project, id, sealed(t, plan)); err != nil {
		t.Fatal(err)
	}
	got, _ = s.Task(id)
	if got.WorkPhase != domain.WorkPhaseImplement || got.PlanRef == "" {
		t.Fatalf("task = %+v", got)
	}
	if got.ResearchRef != researchRef {
		t.Fatal("research ref was overwritten by the plan")
	}
	if got.PlanRef == got.ResearchRef {
		t.Fatal("plan and research sealed to the same ref")
	}

	// implement -> review, then review sends work back to implement.
	if _, err := AdvanceWorkPhase(s, project, id, nil); err != nil {
		t.Fatal(err)
	}
	if got, _ := s.Task(id); got.WorkPhase != domain.WorkPhaseReview {
		t.Fatalf("phase = %q", got.WorkPhase)
	}
	if _, err := AdvanceWorkPhase(s, project, id, nil); err != nil {
		t.Fatal(err)
	}
	if got, _ := s.Task(id); got.WorkPhase != domain.WorkPhaseImplement {
		t.Fatalf("phase = %q, review must be able to return work", got.WorkPhase)
	}
}

// A project that declares a short path skips the phases it omits.
func TestProjectPathSkipsUndeclaredPhases(t *testing.T) {
	s, id := phaseStore(t)
	project := registry.Project{ID: "p", WorkPhases: []domain.WorkPhase{domain.WorkPhaseFrame, domain.WorkPhaseImplement, domain.WorkPhaseReview}}
	if _, err := AdvanceWorkPhase(s, project, id, nil); err != nil {
		t.Fatal(err)
	}
	got, _ := s.Task(id)
	if got.WorkPhase != domain.WorkPhaseImplement {
		t.Fatalf("phase = %q, want implement", got.WorkPhase)
	}
	if got.ResearchRef != "" || got.PlanRef != "" {
		t.Fatal("a skipped phase must not seal an artifact")
	}
}

// The store refuses a phase move that is not legal, whatever a caller asks.
func TestIllegalTransitionRejectedAtTheAppendBoundary(t *testing.T) {
	s, id := phaseStore(t)
	task, _ := s.Task(id)
	b, _ := json.Marshal(map[string]any{"phase": string(domain.WorkPhaseReview)})
	err := s.Append(domain.Event{ID: domain.NewID(), Type: domain.EventWorkPhaseChanged, TaskID: id, Version: task.Version + 1, Payload: b, Surface: string(authz.System)})
	if !errors.Is(err, domain.ErrInvalid) {
		t.Fatalf("frame to review must be rejected, got %v", err)
	}
}

func TestEndOfPathIsRefused(t *testing.T) {
	s, id := phaseStore(t)
	project := registry.Project{ID: "p", WorkPhases: []domain.WorkPhase{domain.WorkPhaseFrame}}
	if _, err := AdvanceWorkPhase(s, project, id, nil); !errors.Is(err, domain.ErrInvalid) {
		t.Fatalf("want ErrInvalid at the end of the path, got %v", err)
	}
}

func TestPhaseChangeDoesNotTouchLifecycle(t *testing.T) {
	s, id := phaseStore(t)
	if _, err := s.Lease(id, "h1", 60_000_000_000); err != nil {
		t.Fatal(err)
	}
	before, _ := s.Task(id)
	if _, err := AdvanceWorkPhase(s, registry.Project{ID: "p"}, id, nil); err != nil {
		t.Fatal(err)
	}
	after, _ := s.Task(id)
	if after.State != before.State {
		t.Fatalf("state changed %s -> %s", before.State, after.State)
	}
	if after.Lease == nil || *after.Lease != *before.Lease {
		t.Fatal("lease changed")
	}
	if after.WorkPhase != domain.WorkPhaseResearch {
		t.Fatalf("phase = %q", after.WorkPhase)
	}
}