package web

import (
	"encoding/json"
	"net/http"
	"net/netip"
	"time"

	"github.com/root-kdw12/hetzner-api-dyndns-records-webinterface/internal/buildinfo"
	"github.com/root-kdw12/hetzner-api-dyndns-records-webinterface/internal/diagnostics"
	"github.com/root-kdw12/hetzner-api-dyndns-records-webinterface/internal/model"
)

// Only this allowlisted report is downloadable, never raw Docker logs, stored
// error messages, audit messages, configuration, credentials or session data.
func (s *Server) downloadDiagnostics(w http.ResponseWriter, r *http.Request, _ *model.Session) {
	settings, err := s.store.GetSettings(r.Context())
	if err != nil {
		s.serverError(w, err)
		return
	}
	runs, err := s.store.RecentRuns(r.Context(), 100)
	if err != nil {
		s.serverError(w, err)
		return
	}
	type run struct {
		ID        int64     `json:"id"`
		StartedAt time.Time `json:"started_at"`
		Status    string    `json:"status"`
	}
	report := struct {
		Format          int                  `json:"format"`
		Version         string               `json:"version"`
		ExportedAt      time.Time            `json:"exported_at"`
		Network         *diagnostics.Network `json:"current_network"`
		UpdaterEnabled  bool                 `json:"updater_enabled"`
		IPv6Enabled     bool                 `json:"ipv6_enabled"`
		IntervalSeconds int                  `json:"interval_seconds"`
		LastIPv4        string               `json:"last_ipv4,omitempty"`
		LastIPv6        string               `json:"last_ipv6,omitempty"`
		Runs            []run                `json:"recent_runs"`
		Events          []diagnostics.Event  `json:"events"`
	}{
		Format: 1, Version: buildinfo.Version, ExportedAt: time.Now().UTC(), Network: diagnostics.CurrentNetwork(),
		UpdaterEnabled: settings.UpdaterEnabled, IPv6Enabled: settings.IPv6Enabled, IntervalSeconds: settings.UpdateIntervalSeconds,
		Events: diagnostics.Snapshot(),
	}
	if ip, err := netip.ParseAddr(settings.LastIPv4); err == nil && ip.Zone() == "" {
		report.LastIPv4 = ip.String()
	}
	if ip, err := netip.ParseAddr(settings.LastIPv6); err == nil && ip.Zone() == "" {
		report.LastIPv6 = ip.String()
	}
	for _, item := range runs {
		status := "unknown"
		switch item.Status {
		case "running", "ok", "error", "partial":
			status = item.Status
		}
		report.Runs = append(report.Runs, run{item.ID, item.StartedAt, status})
	}
	w.Header().Set("Content-Type", "application/json; charset=utf-8")
	w.Header().Set("Content-Disposition", `attachment; filename="domain-control-diagnostics.json"`)
	w.Header().Set("Cache-Control", "no-store")
	w.Header().Set("X-Content-Type-Options", "nosniff")
	encoder := json.NewEncoder(w)
	encoder.SetIndent("", "  ")
	_ = encoder.Encode(report)
}