package httpapi

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

	dbpkg "ai-workflow-skill/packages/coord-core/db"
	"ai-workflow-skill/packages/coord-core/store"
	"ai-workflow-skill/packages/operator-api/internal/app"
)

// TestRouterExposesReadOnlyWebEndpoints verifies the read-only web endpoints return seeded coordination data.
func TestRouterExposesReadOnlyWebEndpoints(t *testing.T) {
	t.Parallel()

	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	dbPath := filepath.Join(t.TempDir(), "coord.db")
	sqlDB, err := dbpkg.Open(ctx, dbPath)
	if err != nil {
		t.Fatalf("open db: %v", err)
	}
	defer sqlDB.Close()

	if err := dbpkg.ApplyMigrations(ctx, sqlDB); err != nil {
		t.Fatalf("apply migrations: %v", err)
	}

	orchStore := store.NewOrchStore(sqlDB)
	inboxStore := store.NewInboxStore(sqlDB)

	_, err = orchStore.CreateRun(ctx, store.CreateRunInput{
		RunID:   "run_web_001",
		Goal:    "Build the web control plane",
		Summary: "Initial HTTP slice",
	})
	if err != nil {
		t.Fatalf("create run: %v", err)
	}

	_, err = orchStore.AddTask(ctx, store.AddTaskInput{
		RunID:     "run_web_001",
		TaskID:    "T1",
		Title:     "Implement read API",
		Summary:   "Expose run state over HTTP",
		DefaultTo: "worker-a",
	})
	if err != nil {
		t.Fatalf("add task T1: %v", err)
	}

	_, err = orchStore.AddTask(ctx, store.AddTaskInput{
		RunID:     "run_web_001",
		TaskID:    "T2",
		Title:     "Build React shell",
		Summary:   "Scaffold the frontend workspace",
		DefaultTo: "worker-b",
	})
	if err != nil {
		t.Fatalf("add task T2: %v", err)
	}

	dispatch, err := orchStore.DispatchTask(ctx, store.DispatchInput{
		RunID:   "run_web_001",
		TaskID:  "T1",
		ToAgent: "worker-a",
		Body:    "Expose the initial HTTP API.",
	})
	if err != nil {
		t.Fatalf("dispatch task: %v", err)
	}

	if _, err := inboxStore.ClaimThread(ctx, store.ClaimInput{
		ThreadID:     dispatch.Attempt.ThreadID,
		Agent:        "worker-a",
		LeaseSeconds: 300,
	}); err != nil {
		t.Fatalf("claim thread: %v", err)
	}

	if _, _, err := inboxStore.UpdateThreadStatus(ctx, store.UpdateInput{
		ThreadID: dispatch.Attempt.ThreadID,
		Agent:    "worker-a",
		Status:   "blocked",
		Summary:  "Need the API shape",
		Body:     "Confirm whether run detail should include blocked tasks.",
	}); err != nil {
		t.Fatalf("mark thread blocked: %v", err)
	}

	if _, err := orchStore.ReconcileRun(ctx, "run_web_001"); err != nil {
		t.Fatalf("reconcile run: %v", err)
	}

	handler := NewRouter(app.NewWebService(sqlDB))

	assertStatusAndJSONField(t, handler, "/health", http.StatusOK, []string{"status"}, "ok")
	assertStatusAndJSONField(t, handler, "/api/runs", http.StatusOK, []string{"runs", "0", "run", "run_id"}, "run_web_001")
	assertStatusAndJSONField(t, handler, "/api/runs/run_web_001", http.StatusOK, []string{"run", "run", "run_id"}, "run_web_001")
	assertStatusAndJSONField(t, handler, "/api/runs/run_web_001/tasks", http.StatusOK, []string{"tasks", "0", "task_id"}, "T1")
	assertStatusAndJSONField(t, handler, "/api/runs/run_web_001/blocked", http.StatusOK, []string{"blocked", "0", "task", "task_id"}, "T1")
	assertStatusAndJSONField(t, handler, "/api/threads/"+dispatch.Attempt.ThreadID, http.StatusOK, []string{"thread", "thread", "thread_id"}, dispatch.Attempt.ThreadID)
}

// TestRouterMapsNotFoundErrors verifies missing resources map to a not_found API error.
func TestRouterMapsNotFoundErrors(t *testing.T) {
	t.Parallel()

	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	dbPath := filepath.Join(t.TempDir(), "coord.db")
	sqlDB, err := dbpkg.Open(ctx, dbPath)
	if err != nil {
		t.Fatalf("open db: %v", err)
	}
	defer sqlDB.Close()

	if err := dbpkg.ApplyMigrations(ctx, sqlDB); err != nil {
		t.Fatalf("apply migrations: %v", err)
	}

	handler := NewRouter(app.NewWebService(sqlDB))
	rec := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, "/api/runs/missing-run", nil)
	handler.ServeHTTP(rec, req)

	if rec.Code != http.StatusNotFound {
		t.Fatalf("expected 404, got %d", rec.Code)
	}

	var payload map[string]any
	if err := json.Unmarshal(rec.Body.Bytes(), &payload); err != nil {
		t.Fatalf("decode response: %v", err)
	}

	code := nestedString(t, payload, "error", "code")
	if code != "not_found" {
		t.Fatalf("expected not_found error code, got %q", code)
	}
}

func assertStatusAndJSONField(t *testing.T, handler http.Handler, path string, wantStatus int, fieldPath []string, want string) {
	t.Helper()

	rec := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, path, nil)
	handler.ServeHTTP(rec, req)

	if rec.Code != wantStatus {
		t.Fatalf("GET %s: expected status %d, got %d", path, wantStatus, rec.Code)
	}

	var payload map[string]any
	if err := json.Unmarshal(rec.Body.Bytes(), &payload); err != nil {
		t.Fatalf("GET %s: decode response: %v", path, err)
	}

	got := nestedString(t, payload, fieldPath...)
	if got != want {
		t.Fatalf("GET %s: expected %q at %v, got %q", path, want, fieldPath, got)
	}
}

func nestedString(t *testing.T, value any, path ...string) string {
	t.Helper()

	current := value
	for _, part := range path {
		switch typed := current.(type) {
		case map[string]any:
			current = typed[part]
		case []any:
			if len(part) != 1 || part[0] < '0' || part[0] > '9' {
				t.Fatalf("path segment %q is not a numeric index", part)
			}
			index := int(part[0] - '0')
			if index >= len(typed) {
				t.Fatalf("index %d out of range for path %v", index, path)
			}
			current = typed[index]
		default:
			t.Fatalf("unsupported type %T at path %v", current, path)
		}
	}

	got, ok := current.(string)
	if !ok {
		t.Fatalf("expected string at path %v, got %T", path, current)
	}
	return got
}