package execution_test

import (
	"errors"
	"path/filepath"
	"testing"
	"time"

	"github.com/kami/hexis/internal/domain"
	"github.com/kami/hexis/internal/execution"
	"github.com/kami/hexis/internal/provider"
	"github.com/kami/hexis/internal/storage"
)

type fakeProvider struct {
	name  string
	delay time.Duration
	err   error
}

func (p *fakeProvider) Name() string { return p.name }

func (p *fakeProvider) Execute(capability *domain.Capability, req *domain.ExecuteRequest) (map[string]any, error) {
	if p.delay > 0 {
		time.Sleep(p.delay)
	}
	if p.err != nil {
		return nil, p.err
	}
	return map[string]any{"ok": true}, nil
}

func newTestEngine(t *testing.T, prov *fakeProvider) (*execution.Engine, *storage.Store) {
	t.Helper()
	dir := t.TempDir()
	store, err := storage.Open(filepath.Join(dir, "hexis.db"))
	if err != nil {
		t.Fatalf("open storage: %v", err)
	}
	t.Cleanup(func() { store.Close() })

	reg := provider.NewRegistry()
	reg.Register(prov)

	return execution.New(store, reg), store
}

func mustCreateCapability(t *testing.T, store storage.Interface, mutate func(*domain.Capability)) *domain.Capability {
	t.Helper()
	now := time.Now().UTC()
	cap := &domain.Capability{
		ID:          domain.NewCapabilityID(),
		Name:        "test.capability",
		Provider:    "fake",
		Operation:   "noop",
		Risk:        "low",
		ReadOnly:    false,
		Enabled:     true,
		CreatedAt:   now,
		UpdatedAt:   now,
		Version:     1,
		TargetTypes: []string{},
		Attributes:  map[string]any{},
	}
	if mutate != nil {
		mutate(cap)
	}
	if err := store.CreateCapability(cap); err != nil {
		t.Fatalf("create capability: %v", err)
	}
	return cap
}

func TestExecute_FreeTextTargetRejectedWhenBound(t *testing.T) {
	prov := &fakeProvider{name: "fake"}
	eng, store := newTestEngine(t, prov)
	cap := mustCreateCapability(t, store, func(c *domain.Capability) {
		c.TargetEntityID = "ent_bound_only"
	})

	_, err := eng.Execute(&domain.ExecuteRequest{
		CapabilityID:   cap.ID,
		TargetEntityID: "ent_someone_else",
	})
	if !errors.Is(err, domain.ErrCapabilityNotBound) {
		t.Fatalf("expected ErrCapabilityNotBound, got %v", err)
	}
}

func TestExecute_DisabledCapabilityRejected(t *testing.T) {
	prov := &fakeProvider{name: "fake"}
	eng, store := newTestEngine(t, prov)
	cap := mustCreateCapability(t, store, func(c *domain.Capability) {
		c.Enabled = false
	})

	_, err := eng.Execute(&domain.ExecuteRequest{CapabilityID: cap.ID, TargetEntityID: "ent_x"})
	if !errors.Is(err, domain.ErrCapabilityDisabled) {
		t.Fatalf("expected ErrCapabilityDisabled, got %v", err)
	}
}

func TestExecute_ConfirmationRequiredButMissing(t *testing.T) {
	prov := &fakeProvider{name: "fake"}
	eng, store := newTestEngine(t, prov)
	cap := mustCreateCapability(t, store, func(c *domain.Capability) {
		c.RequiresConfirmation = true
	})

	_, err := eng.Execute(&domain.ExecuteRequest{CapabilityID: cap.ID, TargetEntityID: "ent_x"})
	if !errors.Is(err, domain.ErrConfirmationRequired) {
		t.Fatalf("expected ErrConfirmationRequired, got %v", err)
	}
}

func TestExecute_ConfirmationValidSucceedsAndIsConsumed(t *testing.T) {
	prov := &fakeProvider{name: "fake"}
	eng, store := newTestEngine(t, prov)
	cap := mustCreateCapability(t, store, func(c *domain.Capability) {
		c.RequiresConfirmation = true
	})

	args := map[string]any{"foo": "bar"}
	conf, err := eng.CreateConfirmation(cap.ID, "ent_x", "kami", args)
	if err != nil {
		t.Fatalf("create confirmation: %v", err)
	}

	res, err := eng.Execute(&domain.ExecuteRequest{
		CapabilityID:   cap.ID,
		TargetEntityID: "ent_x",
		Arguments:      args,
		ConfirmationID: conf.ID,
	})
	if err != nil {
		t.Fatalf("execute: %v", err)
	}
	if res.Execution.Status != domain.ExecutionSucceeded {
		t.Fatalf("expected succeeded, got %s", res.Execution.Status)
	}

	got, err := store.GetConfirmation(conf.ID)
	if err != nil {
		t.Fatalf("get confirmation: %v", err)
	}
	if got.State != domain.ConfirmationConsumed {
		t.Fatalf("expected confirmation consumed, got %s", got.State)
	}

	// Reusing the same confirmation must fail.
	_, err = eng.Execute(&domain.ExecuteRequest{
		CapabilityID:   cap.ID,
		TargetEntityID: "ent_x",
		Arguments:      args,
		ConfirmationID: conf.ID,
	})
	if !errors.Is(err, domain.ErrConfirmationConsumed) {
		t.Fatalf("expected ErrConfirmationConsumed on replay, got %v", err)
	}
}

func TestExecute_ConfirmationExpired(t *testing.T) {
	prov := &fakeProvider{name: "fake"}
	eng, store := newTestEngine(t, prov)
	cap := mustCreateCapability(t, store, func(c *domain.Capability) {
		c.RequiresConfirmation = true
	})

	conf, err := eng.CreateConfirmation(cap.ID, "ent_x", "kami", nil)
	if err != nil {
		t.Fatalf("create confirmation: %v", err)
	}

	// Directly backdate the row's expiry in storage to simulate TTL elapse
	// without waiting out the real 120s TTL in a test.
	if _, err := store.DB().Exec(`UPDATE confirmations SET expires_at = ? WHERE id = ?`,
		time.Now().UTC().Add(-time.Minute).Format("2006-01-02T15:04:05.999999999Z07:00"), conf.ID); err != nil {
		t.Fatalf("backdate confirmation: %v", err)
	}

	_, err = eng.Execute(&domain.ExecuteRequest{
		CapabilityID:   cap.ID,
		TargetEntityID: "ent_x",
		ConfirmationID: conf.ID,
	})
	if !errors.Is(err, domain.ErrConfirmationExpired) {
		t.Fatalf("expected ErrConfirmationExpired, got %v", err)
	}

	got, err := store.GetConfirmation(conf.ID)
	if err != nil {
		t.Fatalf("get confirmation: %v", err)
	}
	if got.State != domain.ConfirmationExpired {
		t.Fatalf("expected confirmation state expired, got %s", got.State)
	}
}

func TestExecute_ArgsHashMismatchRejected(t *testing.T) {
	prov := &fakeProvider{name: "fake"}
	eng, store := newTestEngine(t, prov)
	cap := mustCreateCapability(t, store, func(c *domain.Capability) {
		c.RequiresConfirmation = true
	})

	conf, err := eng.CreateConfirmation(cap.ID, "ent_x", "kami", map[string]any{"n": 1})
	if err != nil {
		t.Fatalf("create confirmation: %v", err)
	}

	_, err = eng.Execute(&domain.ExecuteRequest{
		CapabilityID:   cap.ID,
		TargetEntityID: "ent_x",
		Arguments:      map[string]any{"n": 2},
		ConfirmationID: conf.ID,
	})
	if !errors.Is(err, domain.ErrConfirmationInvalid) {
		t.Fatalf("expected ErrConfirmationInvalid on args mismatch, got %v", err)
	}
}

func TestExecute_UnknownCapabilityVersionRejected(t *testing.T) {
	prov := &fakeProvider{name: "fake"}
	eng, store := newTestEngine(t, prov)
	cap := mustCreateCapability(t, store, func(c *domain.Capability) {
		c.RequiresConfirmation = true
	})

	conf, err := eng.CreateConfirmation(cap.ID, "ent_x", "kami", nil)
	if err != nil {
		t.Fatalf("create confirmation: %v", err)
	}
	// Bump the capability version (e.g. via update) so the confirmation now
	// targets a stale version.
	cap.Description = "changed"
	if err := store.UpdateCapability(cap); err != nil {
		t.Fatalf("update capability: %v", err)
	}

	_, err = eng.Execute(&domain.ExecuteRequest{
		CapabilityID:   cap.ID,
		TargetEntityID: "ent_x",
		ConfirmationID: conf.ID,
	})
	if !errors.Is(err, domain.ErrConfirmationInvalid) {
		t.Fatalf("expected ErrConfirmationInvalid on stale version, got %v", err)
	}
}

func TestExecute_ConcurrentInFlightRejected(t *testing.T) {
	prov := &fakeProvider{name: "fake", delay: 300 * time.Millisecond}
	eng, store := newTestEngine(t, prov)
	cap := mustCreateCapability(t, store, nil)

	done := make(chan struct{})
	go func() {
		eng.Execute(&domain.ExecuteRequest{CapabilityID: cap.ID, TargetEntityID: "ent_x"})
		close(done)
	}()

	// Give the first execution time to register as "started".
	time.Sleep(50 * time.Millisecond)

	_, err := eng.Execute(&domain.ExecuteRequest{CapabilityID: cap.ID, TargetEntityID: "ent_x"})
	if !errors.Is(err, domain.ErrExecutionInFlight) {
		t.Fatalf("expected ErrExecutionInFlight, got %v", err)
	}

	<-done
}

func TestExecute_TimeoutYieldsUnknownNotFailed(t *testing.T) {
	// Smallest supported capability timeout is 1s; use a provider slower
	// than that so the engine's context deadline fires first.
	prov := &fakeProvider{name: "slow", delay: 1500 * time.Millisecond}
	eng, store := newTestEngine(t, prov)
	cap := mustCreateCapability(t, store, func(c *domain.Capability) {
		c.TimeoutSeconds = 1
		c.Provider = "slow"
	})

	res, err := eng.Execute(&domain.ExecuteRequest{CapabilityID: cap.ID, TargetEntityID: "ent_x"})
	if err != nil {
		t.Fatalf("execute: %v", err)
	}
	if res.Execution.Status != domain.ExecutionUnknown {
		t.Fatalf("expected status unknown on timeout, got %s", res.Execution.Status)
	}

	// Let the background provider goroutine finish so t.Cleanup can close
	// the store without a dangling write racing it.
	time.Sleep(1600 * time.Millisecond)
}