package webapp

import (
	"net/http"
	"strings"
	"time"
)

// handleOverview is the landing page after login. Phase 1 shows the
// worker status, recent results counts, and a tail of the worker
// log buffer. The data shape will grow in later phases as the
// heartbeat inventory and 24h result counts come online.
func (s *Server) handleOverview(w http.ResponseWriter, r *http.Request) {
	writeNoStore(w)
	sess, _ := sessionFromContext(r.Context())
	snap, snapAt := s.metrics.Last()
	data := overviewPageData{
		basePageData:    s.newBasePage(r, "Overview", sess),
		WorkerID:        workerIDOrDash(s.deps.Runner),
		RegionCode:      regionOrDash(s.deps.Runner),
		WorkerState:     workerState(s.deps.Runner, s.deps.StartedAt),
		LastAckAt:       lastAckOrZero(s.deps.Runner),
		StartedAt:       s.deps.StartedAt,
		Snapshot:        snap,
		SnapshotAt:      snapAt,
		DiscoveredCount: len(s.inventory.Snapshot()),
		ResultCount:     len(s.deps.Runner.RecentResults(1000)),
		NotifCount:      len(s.deps.Runner.RecentNotifications(1000)),
		LogTail:         s.logBuffer.Tail(20),
	}
	if err := s.templates.Execute(w, "overview.html", data); err != nil {
		s.deps.Logger.Printf("render overview: %v", err)
		http.Error(w, "template error", http.StatusInternalServerError)
	}
}

func workerIDOrDash(v WorkerView) string {
	if v == nil {
		return "—"
	}
	return v.WorkerID()
}

func regionOrDash(v WorkerView) string {
	if v == nil {
		return "—"
	}
	return v.RegionCode()
}

func workerState(v WorkerView, startedAt time.Time) string {
	if v == nil {
		return "—"
	}
	if last := v.LastHeartbeatAck(); !last.IsZero() && last.After(startedAt) {
		return "connected"
	}
	return "starting"
}

func lastAckOrZero(v WorkerView) time.Time {
	if v == nil {
		return time.Time{}
	}
	return v.LastHeartbeatAck()
}

// overviewPageData is the data backing overview.html.
type overviewPageData struct {
	basePageData
	WorkerID        string
	RegionCode      string
	WorkerState     string
	LastAckAt       time.Time
	StartedAt       time.Time
	Snapshot        Snapshot
	SnapshotAt      time.Time
	DiscoveredCount int
	ResultCount     int
	NotifCount      int
	LogTail         []string
}

var _ = strings.TrimSpace