package localapi

import (
	"context"
	"errors"
	"net/http"
	"time"

	"gitea.dooplex.hu/admin/felhom-agent/internal/linetest"
)

// LineTestReader is the R-1247 weekly upload line test (internal/linetest.Tester) as the local API reads it.
type LineTestReader interface {
	Value() (mbps float64, at time.Time, ok bool)
}

// LineTestRequester is the R-1250 half: a due test the uplink never lets start, and a test on request. The Tester
// satisfies it; a reader without it answers waiting_for_quiet:false and 503 on the POST.
type LineTestRequester interface {
	WaitingForQuiet() bool
	RunNow(ctx context.Context) (mbps float64, runs []float64, err error)
}

// LineTestResponse is GET /host/line-test. Present=false: never measured, or the job is not wired (no tunnel, disabled,
// or an agent before the route answers 404 — the controller reads all three as „unknown").
type LineTestResponse struct {
	Present    bool    `json:"present"`
	Mbps       float64 `json:"mbps,omitempty"`
	MeasuredAt string  `json:"measured_at,omitempty"` // RFC3339 UTC
	Method     string  `json:"method,omitempty"`      // "iperf3-tunnel": a 10-second upload to ep0 inside the tunnel
	// WaitingForQuiet: a measurement is due and could start now, but the uplink has not been quiet for 10 minutes
	// (R-1250). The controller with a seeding torrent app then holds its limit and POSTs /host/line-test/run.
	WaitingForQuiet bool `json:"waiting_for_quiet,omitempty"`
}

// LineTestRunResponse is POST /host/line-test/run. OK=false with Refused: nothing ran (Refused is linetest.Refusal's
// code, or "server-busy"); OK=false without it: the runs failed.
type LineTestRunResponse struct {
	OK       bool      `json:"ok"`
	Mbps     float64   `json:"mbps,omitempty"`
	RunsMbps []float64 `json:"runs_mbps,omitempty"`
	Refused  string    `json:"refused,omitempty"`
	Error    string    `json:"error,omitempty"`
}

// SetLineTest wires the weekly line test (main.go builds it after the local API server).
func (s *Server) SetLineTest(r LineTestReader) { s.lineTest = r }

func (s *Server) handleLineTest(w http.ResponseWriter, r *http.Request, vmid int) {
	if s.lineTest == nil {
		writeOK(w, LineTestResponse{Present: false})
		return
	}
	var waiting bool
	if q, ok := s.lineTest.(LineTestRequester); ok {
		waiting = q.WaitingForQuiet()
	}
	mbps, at, ok := s.lineTest.Value()
	if !ok {
		writeOK(w, LineTestResponse{Present: false, WaitingForQuiet: waiting})
		return
	}
	s.logger.Debug("local-api: /host/line-test served", "vmid", vmid, "mbps", mbps, "measured_at", at.UTC().Format(time.RFC3339), "waiting_for_quiet", waiting)
	writeOK(w, LineTestResponse{Present: true, Mbps: mbps, MeasuredAt: at.UTC().Format(time.RFC3339), Method: "iperf3-tunnel", WaitingForQuiet: waiting})
}

// handleLineTestRun is POST /host/line-test/run (R-1250): a test on request, synchronous (about 55 s). The answer is
// always 200 with the outcome in the body, except 503 when no line test is wired.
func (s *Server) handleLineTestRun(w http.ResponseWriter, r *http.Request, vmid int) {
	q, ok := s.lineTest.(LineTestRequester)
	if s.lineTest == nil || !ok {
		writeErr(w, http.StatusServiceUnavailable, "line test not configured")
		return
	}
	s.logger.Info("local-api: line test requested", "vmid", vmid)
	mbps, runs, err := q.RunNow(r.Context())
	var ref *linetest.Refusal
	switch {
	case err == nil:
		writeOK(w, LineTestRunResponse{OK: true, Mbps: mbps, RunsMbps: runs})
	case errors.As(err, &ref):
		s.logger.Info("local-api: line test request refused", "vmid", vmid, "reason", ref.Code, "detail", ref.Msg)
		writeOK(w, LineTestRunResponse{Refused: ref.Code, Error: ref.Msg})
	case errors.Is(err, linetest.ErrBusy):
		writeOK(w, LineTestRunResponse{Refused: "server-busy", Error: err.Error()})
	default:
		writeOK(w, LineTestRunResponse{Error: err.Error()})
	}
}