//go:build live

// Live tests hit the real origin and need this module's local module.yaml.
// They are excluded from the normal test run; enable with:
//
//	go -C apps/modules test -tags live ./rte/ -v
package rte

import (
	"regexp"
	"strconv"
	"strings"
	"testing"

	"drmdecryption/mpd"
)

// The rewriter must publish a usable manifest from the KID alone — this is the
// path taken when the ad-stitched upstream session has expired (HTTP 410) and all
// that is left is the key from an earlier capture.
func TestLiveRewriteFromKIDOnly(t *testing.T) {
	cfg, res, err := loadConfig()
	if err != nil {
		t.Fatal(err)
	}
	if !res.Loaded {
		t.Skipf("no local values at %s", res.Path)
	}
	if len(cfg.KIDs) == 0 {
		t.Skip("no kids configured")
	}

	for channel, kid := range cfg.KIDs {
		t.Run(channel, func(t *testing.T) {
			resetCaches(channel)
			r := NewRewriterWith(cfg)

			// Empty upstream = expired session; only the KID hint is available.
			out, err := r.Rewrite(nil, kid)
			if err != nil {
				t.Fatalf("rewrite from KID: %v", err)
			}
			got := string(out)

			origin := cfg.Origins[channel]
			if origin == "" {
				t.Fatalf("no origin configured for %s", channel)
			}
			for _, want := range []string{
				`type="dynamic"`,
				origin + cfg.Synthetic.SegmentPathSuffix,
				channel + "-" + cfg.Synthetic.VideoName,
				channel + "-" + cfg.Synthetic.AudioName,
			} {
				if !strings.Contains(got, want) {
					t.Errorf("manifest missing %q", want)
				}
			}
			u, _ := mpd.KIDToUUID(kid)
			if !strings.Contains(got, `cenc:default_KID="`+u+`"`) {
				t.Errorf("manifest does not carry KID %s", u)
			}

			// The timeline must be non-empty and on the encoder grid, or the
			// downloader asks the origin for segments that do not exist.
			re := regexp.MustCompile(`<S t="(\d+)" d="(\d+)" r="(\d+)"/>`)
			ms := re.FindAllStringSubmatch(got, -1)
			if len(ms) != 2 {
				t.Fatalf("want 2 timelines, got %d", len(ms))
			}
			grid, err := mpd.LearnGrid(channel, origin, cfg.Synthetic.GridSpec())
			if err != nil {
				t.Fatalf("learn grid: %v", err)
			}
			for i, m := range ms {
				start, _ := strconv.ParseInt(m[1], 10, 64)
				dur, _ := strconv.ParseInt(m[2], 10, 64)
				rep, _ := strconv.Atoi(m[3])
				wantDur, mod := grid.VDur, grid.VMod
				if i == 1 {
					wantDur, mod = grid.ADur, grid.AMod
				}
				if dur != wantDur {
					t.Errorf("timeline %d: d=%d, want %d (from the live origin)", i, dur, wantDur)
				}
				if int64(rep+1) != cfg.Synthetic.WindowSegments {
					t.Errorf("timeline %d: %d segments, want %d", i, rep+1, cfg.Synthetic.WindowSegments)
				}
				if off := ((start-mod)%wantDur + wantDur) % wantDur; off != 0 {
					t.Errorf("timeline %d: start %d is off the encoder grid by %d", i, start, off)
				}
				if start <= 0 {
					t.Errorf("timeline %d: non-positive start %d", i, start)
				}
			}
			t.Logf("%s: %d bytes, vdur=%d adur=%d", channel, len(out), grid.VDur, grid.ADur)
		})
	}
}

// The KID→channel→origin lookup is what makes the expired-session path work.
func TestLiveKIDResolvesToConfiguredOrigin(t *testing.T) {
	cfg, res, err := loadConfig()
	if err != nil {
		t.Fatal(err)
	}
	if !res.Loaded {
		t.Skipf("no local values at %s", res.Path)
	}
	r := NewRewriterWith(cfg)
	for channel, kid := range cfg.KIDs {
		gotCh, gotBase, ok := r.ResolveKID(mpd.KIDHex(kid))
		if !ok {
			t.Errorf("%s: KID %s did not resolve", channel, kid)
			continue
		}
		if gotCh != channel {
			t.Errorf("KID %s resolved to %q, want %q", kid, gotCh, channel)
		}
		if gotBase != cfg.Origins[channel] {
			t.Errorf("%s: origin %q, want %q", channel, gotBase, cfg.Origins[channel])
		}
	}
}

func resetCaches(channel string) {
	// The grid/anchor caches live in pkg/mpd and are keyed by channel; a fresh
	// process per test run is enough, so nothing to do here beyond documenting it.
	_ = channel
}