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/session"

	"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 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)
	}
}

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)
	}
}