package web

import (
	"context"
	"net/http"
	"net/http/httptest"
	"path/filepath"
	"strings"
	"testing"
	"time"

	"antidrift/internal/ai"
	"antidrift/internal/domain"
	"antidrift/internal/evidence"
	"antidrift/internal/knowledge"
	"antidrift/internal/session"
	"antidrift/internal/tasks"

	"github.com/gin-gonic/gin"
)

func newTestServer(t *testing.T) *Server {
	t.Helper()
	gin.SetMode(gin.TestMode)
	path := filepath.Join(t.TempDir(), "state.json")
	ctrl, err := session.New(path)
	if err != nil {
		t.Fatalf("controller: %v", err)
	}
	return NewServer(ctrl)
}

func post(t *testing.T, r http.Handler, path, body string) *httptest.ResponseRecorder {
	t.Helper()
	req := httptest.NewRequest(http.MethodPost, path, strings.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()
	r.ServeHTTP(w, req)
	return w
}

func TestPlanningThenCommitmentReachesActive(t *testing.T) {
	s := newTestServer(t)
	r := s.Router()

	if w := post(t, r, "/planning", ""); w.Code != http.StatusOK {
		t.Fatalf("/planning code %d", w.Code)
	}
	body := `{"next_action":"Build web","success_condition":"web tests pass","timebox_secs":1500}`
	if w := post(t, r, "/commitment", body); w.Code != http.StatusOK {
		t.Fatalf("/commitment code %d body %s", w.Code, w.Body.String())
	}
	if s.ctrl.State().RuntimeState != domain.RuntimeActive {
		t.Fatalf("expected Active, got %s", s.ctrl.State().RuntimeState)
	}
}

func TestCommitmentRejectsInvalidInput(t *testing.T) {
	s := newTestServer(t)
	r := s.Router()
	_ = post(t, r, "/planning", "")
	body := `{"next_action":"","success_condition":"x","timebox_secs":1500}`
	w := post(t, r, "/commitment", body)
	if w.Code != http.StatusBadRequest {
		t.Fatalf("expected 400, got %d", w.Code)
	}
}

func TestIllegalTransitionReturns409(t *testing.T) {
	s := newTestServer(t)
	r := s.Router()
	// /complete from Locked is illegal.
	w := post(t, r, "/complete", "")
	if w.Code != http.StatusConflict {
		t.Fatalf("expected 409, got %d", w.Code)
	}
}

func TestActiveStatePayloadCarriesEvidence(t *testing.T) {
	s := newTestServer(t)
	r := s.Router()
	_ = post(t, r, "/planning", "")
	body := `{"next_action":"Build web","success_condition":"web tests pass","timebox_secs":1500}`
	if w := post(t, r, "/commitment", body); w.Code != http.StatusOK {
		t.Fatalf("/commitment code %d body %s", w.Code, w.Body.String())
	}
	// A focus update should appear in the serialized state.
	s.ctrl.RecordWindow(evidence.WindowSnapshot{Class: "code", Title: "antidrift", Health: evidence.EvidenceHealth{Available: true}})

	js := s.stateJSON()
	if !strings.Contains(js, `"evidence"`) {
		t.Fatalf("payload missing evidence object: %s", js)
	}
	if !strings.Contains(js, `"class":"code"`) {
		t.Fatalf("payload missing current window: %s", js)
	}
}

func TestLockedStateHasNullEvidence(t *testing.T) {
	s := newTestServer(t)
	js := s.stateJSON()
	if !strings.Contains(js, `"evidence":null`) {
		t.Fatalf("locked payload should have null evidence: %s", js)
	}
}

type stubCoach struct {
	prop ai.Proposal
	err  error
}

func (s stubCoach) Coach(ctx context.Context, intent, grounding string) (ai.Proposal, error) {
	return s.prop, s.err
}

func TestCoachRouteHappyPath(t *testing.T) {
	s := newTestServer(t)
	s.ctrl.SetCoach(stubCoach{prop: ai.Proposal{NextAction: "Do X", SuccessCondition: "done", TimeboxSecs: 1500}})
	r := s.Router()
	_ = post(t, r, "/planning", "")
	if w := post(t, r, "/coach", `{"intent":"do something"}`); w.Code != http.StatusOK {
		t.Fatalf("/coach code %d body %s", w.Code, w.Body.String())
	}
	deadline := time.Now().Add(2 * time.Second)
	for time.Now().Before(deadline) {
		if cv := s.ctrl.State().Coach; cv != nil && cv.Status == "ready" {
			return
		}
		time.Sleep(5 * time.Millisecond)
	}
	t.Fatalf("coach never reached ready: %+v", s.ctrl.State().Coach)
}

func TestCoachRouteOutsidePlanning(t *testing.T) {
	s := newTestServer(t)
	s.ctrl.SetCoach(stubCoach{})
	r := s.Router()
	if w := post(t, r, "/coach", `{"intent":"x"}`); w.Code != http.StatusBadRequest {
		t.Fatalf("expected 400, got %d", w.Code)
	}
}

func TestCoachRouteInvalidJSON(t *testing.T) {
	s := newTestServer(t)
	r := s.Router()
	_ = post(t, r, "/planning", "")
	if w := post(t, r, "/coach", `not json`); w.Code != http.StatusBadRequest {
		t.Fatalf("expected 400, got %d", w.Code)
	}
}

func TestCoachRouteUnavailableDegrades(t *testing.T) {
	s := newTestServer(t) // no SetCoach
	r := s.Router()
	_ = post(t, r, "/planning", "")
	if w := post(t, r, "/coach", `{"intent":"x"}`); w.Code != http.StatusOK {
		t.Fatalf("unavailable coach should still 200, got %d", w.Code)
	}
	if cv := s.ctrl.State().Coach; cv == nil || cv.Status != "error" {
		t.Fatalf("want error status, got %+v", cv)
	}
}

func TestRefocusAndOnTaskOutsideActiveIs400(t *testing.T) {
	s := newTestServer(t)
	r := s.Router()
	if w := post(t, r, "/refocus", ""); w.Code != http.StatusBadRequest {
		t.Fatalf("refocus outside Active: want 400, got %d", w.Code)
	}
	if w := post(t, r, "/ontask", ""); w.Code != http.StatusBadRequest {
		t.Fatalf("ontask outside Active: want 400, got %d", w.Code)
	}
}

type stubNudger struct{ msg string }

func (s stubNudger) Nudge(ctx context.Context, commitment string, recentTitles []string) (string, error) {
	return s.msg, nil
}

func TestActiveStatePayloadCarriesNudge(t *testing.T) {
	s := newTestServer(t)
	s.ctrl.SetNudge(stubNudger{msg: "drifted to unrelated work"})
	r := s.Router()
	_ = post(t, r, "/planning", "")
	body := `{"next_action":"Build web","success_condition":"web tests pass","timebox_secs":1500,"allowed_window_classes":["code"]}`
	if w := post(t, r, "/commitment", body); w.Code != http.StatusOK {
		t.Fatalf("/commitment code %d body %s", w.Code, w.Body.String())
	}
	// Two distinct on-task titles trip the nudge (history >= 2; first call has no
	// debounce to wait on).
	s.ctrl.RecordWindow(evidence.WindowSnapshot{Class: "code", Title: "a.go", Health: evidence.EvidenceHealth{Available: true}})
	s.ctrl.RecordWindow(evidence.WindowSnapshot{Class: "code", Title: "b.go", Health: evidence.EvidenceHealth{Available: true}})

	deadline := time.Now().Add(2 * time.Second)
	for time.Now().Before(deadline) {
		if d := s.ctrl.State().Drift; d != nil && d.Nudge != "" {
			break
		}
		time.Sleep(5 * time.Millisecond)
	}
	js := s.stateJSON()
	if !strings.Contains(js, `"nudge":"drifted to unrelated work"`) {
		t.Fatalf("payload missing nudge: %s", js)
	}
}

func TestServesStaticAssets(t *testing.T) {
	s := newTestServer(t)
	r := s.Router()

	cases := []struct {
		path     string
		ctSubstr string
	}{
		{"/app.css", "css"},
		{"/app.js", "javascript"},
	}
	for _, tc := range cases {
		req := httptest.NewRequest(http.MethodGet, tc.path, nil)
		w := httptest.NewRecorder()
		r.ServeHTTP(w, req)
		if w.Code != http.StatusOK {
			t.Errorf("GET %s code = %d, want 200", tc.path, w.Code)
		}
		if ct := w.Header().Get("Content-Type"); !strings.Contains(ct, tc.ctSubstr) {
			t.Errorf("GET %s Content-Type = %q, want substring %q", tc.path, ct, tc.ctSubstr)
		}
		if w.Body.Len() == 0 {
			t.Errorf("GET %s body is empty", tc.path)
		}
	}
}

type stubProvider struct {
	list []tasks.Task
}

func (s stubProvider) Today(ctx context.Context) ([]tasks.Task, error) {
	return s.list, nil
}

func TestPlanningStatePayloadCarriesTasks(t *testing.T) {
	s := newTestServer(t)
	s.ctrl.SetTasks(stubProvider{list: []tasks.Task{{ID: "a", Title: "Write the spec", Day: "2026-05-31"}}})
	r := s.Router()
	if w := post(t, r, "/planning", ""); w.Code != http.StatusOK {
		t.Fatalf("/planning code %d", w.Code)
	}
	deadline := time.Now().Add(2 * time.Second)
	for time.Now().Before(deadline) {
		if tv := s.ctrl.State().Tasks; tv != nil && tv.Status == "ready" {
			break
		}
		time.Sleep(5 * time.Millisecond)
	}
	js := s.stateJSON()
	if !strings.Contains(js, `"tasks"`) {
		t.Fatalf("planning payload missing tasks object: %s", js)
	}
	if !strings.Contains(js, `"title":"Write the spec"`) {
		t.Fatalf("planning payload missing task title: %s", js)
	}
}

func TestCommitmentCarriesAllowedClassesAndRoutesWork(t *testing.T) {
	s := newTestServer(t)
	r := s.Router()
	_ = post(t, r, "/planning", "")
	body := `{"next_action":"a","success_condition":"b","timebox_secs":1500,"allowed_window_classes":["code"]}`
	if w := post(t, r, "/commitment", body); w.Code != http.StatusOK {
		t.Fatalf("commitment: want 200, got %d (%s)", w.Code, w.Body.String())
	}
	if got := s.ctrl.AllowedClassesForTest(); len(got) != 1 || got[0] != "code" {
		t.Fatalf("commitment did not carry allowed classes: %#v", got)
	}
	// Now Active: overrides succeed.
	if w := post(t, r, "/ontask", ""); w.Code != http.StatusOK {
		t.Fatalf("ontask while Active: want 200, got %d", w.Code)
	}
	if w := post(t, r, "/refocus", ""); w.Code != http.StatusOK {
		t.Fatalf("refocus while Active: want 200, got %d", w.Code)
	}
}

type stubSource struct {
	profile knowledge.Profile
}

func (s stubSource) Load(ctx context.Context, path string) (knowledge.Profile, error) {
	if path != "" {
		return knowledge.Profile{Text: "from " + path, Path: path}, nil
	}
	return s.profile, nil
}

func TestPlanningStatePayloadCarriesKnowledge(t *testing.T) {
	s := newTestServer(t)
	s.ctrl.SetKnowledge(stubSource{profile: knowledge.Profile{Text: "I value small diffs.", Path: "/home/u/.antidrift/knowledge.md"}})
	r := s.Router()
	if w := post(t, r, "/planning", ""); w.Code != http.StatusOK {
		t.Fatalf("/planning code %d", w.Code)
	}
	deadline := time.Now().Add(2 * time.Second)
	for time.Now().Before(deadline) {
		if kv := s.ctrl.State().Knowledge; kv != nil && kv.Status == "ready" {
			break
		}
		time.Sleep(5 * time.Millisecond)
	}
	js := s.stateJSON()
	if !strings.Contains(js, `"knowledge"`) || !strings.Contains(js, `"status":"ready"`) {
		t.Fatalf("planning payload missing knowledge object: %s", js)
	}
	if strings.Contains(js, "small diffs") {
		t.Fatalf("profile text must NOT cross the wire: %s", js)
	}
}

type stubReviewer struct {
	refl ai.Reflection
}

func (s stubReviewer) Review(ctx context.Context, finished, history string) (ai.Reflection, error) {
	return s.refl, nil
}

func TestReflectionFlowsToReviewThenPlanning(t *testing.T) {
	s := newTestServer(t)
	s.ctrl.SetReviewer(stubReviewer{refl: ai.Reflection{Recap: "held focus well", CarryForward: "start in the editor"}})
	r := s.Router()
	_ = post(t, r, "/planning", "")
	body := `{"next_action":"a","success_condition":"b","timebox_secs":1500}`
	if w := post(t, r, "/commitment", body); w.Code != http.StatusOK {
		t.Fatalf("/commitment code %d body %s", w.Code, w.Body.String())
	}
	if w := post(t, r, "/complete", ""); w.Code != http.StatusOK {
		t.Fatalf("/complete code %d", w.Code)
	}
	deadline := time.Now().Add(2 * time.Second)
	for time.Now().Before(deadline) {
		if rv := s.ctrl.State().Reflection; rv != nil && rv.Status == "ready" {
			break
		}
		time.Sleep(5 * time.Millisecond)
	}
	js := s.stateJSON()
	if !strings.Contains(js, `"recap":"held focus well"`) {
		t.Fatalf("review payload missing recap: %s", js)
	}

	// End -> Locked -> Planning: the carry-forward should surface on planning.
	if w := post(t, r, "/end", ""); w.Code != http.StatusOK {
		t.Fatalf("/end code %d", w.Code)
	}
	if w := post(t, r, "/planning", ""); w.Code != http.StatusOK {
		t.Fatalf("/planning code %d", w.Code)
	}
	js2 := s.stateJSON()
	if !strings.Contains(js2, `"carry_forward":"start in the editor"`) {
		t.Fatalf("planning payload missing carry-forward: %s", js2)
	}
}

func TestKnowledgePathSelectionReloads(t *testing.T) {
	s := newTestServer(t)
	s.ctrl.SetKnowledge(stubSource{profile: knowledge.Profile{Path: "/default"}})
	r := s.Router()
	if w := post(t, r, "/planning", ""); w.Code != http.StatusOK {
		t.Fatalf("/planning code %d", w.Code)
	}
	if w := post(t, r, "/knowledge/path", `{"path":"/custom/profile.md"}`); w.Code != http.StatusOK {
		t.Fatalf("/knowledge/path code %d body %s", w.Code, w.Body.String())
	}
	deadline := time.Now().Add(2 * time.Second)
	for time.Now().Before(deadline) {
		if kv := s.ctrl.State().Knowledge; kv != nil && kv.Path == "/custom/profile.md" {
			return
		}
		time.Sleep(5 * time.Millisecond)
	}
	t.Fatalf("path selection did not reload: %+v", s.ctrl.State().Knowledge)
}