package httpapp

import (
	"encoding/json"
	"log"
	"net/http"
	"time"
)

func (a *App) handleDashboard(w http.ResponseWriter, r *http.Request) {
	data := map[string]any{
		"Title": "Dashboard",
		"Build": map[string]string{
			"version": "v0.1.0-dev",
		},
	}
	a.render(w, "dashboard.html", data)
}

func (a *App) handleHealthz(w http.ResponseWriter, r *http.Request) {
	id, _ := r.Context().Value(requestIDKey).(string)
	resp := map[string]any{
		"status": "ok",
		"ts":     id, // request ID for correlation
	}
	writeJSON(w, http.StatusOK, resp)
}

func (a *App) handleMetrics(w http.ResponseWriter, r *http.Request) {
	// Collect real-time metrics
	// ZFS metrics
	pools, _ := a.zfs.ListPools()
	datasets, _ := a.zfs.ListDatasets("")
	zvols, _ := a.zfs.ListZVOLs("")
	snapshots, _ := a.zfs.ListSnapshots("")

	a.metricsCollector.UpdateZFSMetrics(pools, datasets, zvols, snapshots)

	// Service metrics
	smbShares := a.smbStore.List()
	nfsExports := a.nfsStore.List()
	iscsiTargets := a.iscsiStore.List()

	smbStatus, _ := a.smbService.GetStatus()
	nfsStatus, _ := a.nfsService.GetStatus()
	iscsiStatus, _ := a.iscsiService.GetStatus()

	a.metricsCollector.UpdateServiceMetrics(
		len(smbShares),
		len(nfsExports),
		len(iscsiTargets),
		smbStatus,
		nfsStatus,
		iscsiStatus,
	)

	// Job metrics
	allJobs := a.jobManager.List("")
	running := 0
	completed := 0
	failed := 0
	for _, job := range allJobs {
		switch job.Status {
		case "running":
			running++
		case "completed":
			completed++
		case "failed":
			failed++
		}
	}

	a.metricsCollector.UpdateJobMetrics(len(allJobs), running, completed, failed)

	// Update uptime
	a.metricsCollector.SetUptime(int64(time.Since(a.startTime).Seconds()))

	// Output Prometheus format
	w.Header().Set("Content-Type", "text/plain; version=0.0.4")
	w.WriteHeader(http.StatusOK)
	_, _ = w.Write([]byte(a.metricsCollector.Collect()))
}

func (a *App) render(w http.ResponseWriter, name string, data any) {
	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	// base.html defines layout; dashboard.html will invoke it via template inheritance style.
	if err := a.tmpl.ExecuteTemplate(w, name, data); err != nil {
		log.Printf("template render error: %v", err)
		http.Error(w, "template render error", http.StatusInternalServerError)
		return
	}
}

func writeJSON(w http.ResponseWriter, code int, v any) {
	w.Header().Set("Content-Type", "application/json; charset=utf-8")
	w.WriteHeader(code)
	if err := json.NewEncoder(w).Encode(v); err != nil {
		log.Printf("json encode error: %v", err)
	}
}