#!/usr/bin/env bash
# Materialise the Suramadu config, the Jetty properties and MegaMek's client
# settings for this match.
#
# All three are rendered at launch rather than baked into the image because each
# carries something the image cannot know: the player name that the Swing client
# logs in as, and the ports. Everything else in them is fixed and lives in
# config/*.template under review.
#
# MegaMek rewrites clientsettings.xml on exit, so seeding it once at image build
# would not survive; it is re-seeded per launch.
set -euo pipefail
# shellcheck disable=SC2034  # read by common.sh's log helpers
ARENA_LOG_TAG=init/config
# shellcheck source=../lib/common.sh
. "${ARENA_HOME:-/opt/arena}/container/lib/common.sh"

# shellcheck source=/dev/null
. "$ARENA_RUN/players.env"

MM_HOME="${MM_HOME:-$ARENA_HOME/megamek}"
JAVA="${JAVA:-$ARENA_HOME/jre/bin/java}"
CLIENT_HEAP="${ARENA_CLIENT_HEAP:-2G}"

# The paint dispatcher tick. A change waits for the next one, so it is worth
# about a tick and a half of latency per repaint - the largest server-side term
# in a warm input-to-paint once the board has been sent. 33 was upstream's, 16
# is measured better (see PERFORMANCE.md); this makes going lower an experiment
# rather than a rebuild.
DRAW_DELAY_MS="${ARENA_DRAW_DELAY_MS:-16}"

# Anything else to put on the client JVM, for an experiment that would
# otherwise want a rebuild to change one system property. Appended last so it
# can override what is set above. Empty in every ordinary match.
CLIENT_VMARGS="${ARENA_CLIENT_VMARGS:-}"
case "$DRAW_DELAY_MS" in
  ''|*[!0-9]*) die "ARENA_DRAW_DELAY_MS must be a whole number of milliseconds, got '$DRAW_DELAY_MS'" ;;
esac

mkdir -p "$ARENA_RUN/suramadu"

# Served by Suramadu in place of the war's own index.html; see
# suramadu/web/ in the repo.
#
# Copied into the run directory rather than served from the image, because one
# file in it is written while the match is on: container/watch/results.sh drops
# the result there the instant the game is decided, and suramadu/web/report.js
# fetches it from the page. The image tree is owned by root and this runs as
# uid 10001, so the copy is what makes that directory writable at all.
#
# The alternative was for the page to wait on the result reaching S3 and
# headquarters serving it back, which is a good five seconds of network for a
# document that is already sitting in this container.
WEB_FOLDER="${WEB_FOLDER:-$ARENA_WEB}"
if [ "$WEB_FOLDER" = "$ARENA_WEB" ]; then
  if [ -d "$ARENA_HOME/web" ]; then
    rm -rf "$ARENA_WEB"
    cp -r "$ARENA_HOME/web" "$ARENA_WEB"
    log "web folder staged at $ARENA_WEB ($(find "$ARENA_WEB" -type f | wc -l) files)"
  else
    # A checkout that has not assembled an image tree. The war's own page is
    # served instead, which loses the theme and the report - but a config that
    # points at a directory with no index.html in it serves nothing at all.
    warn "no web folder at $ARENA_HOME/web; serving the war's own page"
    WEB_FOLDER="$ARENA_HOME/web"
  fi
fi

# --- the profiling agent, if this match is being profiled ---------------------
# The client JVM is the one Suramadu spawns, so the only way to put a flag on it
# is through vmArgs here. Empty unless ARENA_PROFILE is set to something other
# than 0, and it substitutes to nothing, so an unprofiled match renders the
# config it rendered before this existed.
#
# Wall clock, not CPU: the question the client JVM has to answer is where the
# EDT's *latency* goes, and a blocked EDT costs a player exactly as much as a
# busy one. CPU time on the host JVM is a different question; see
# container/entrypoint.sh.
#
# DebugNonSafepoints makes the JIT keep debug info at non-safepoint PCs, without
# which inlined frames are attributed to whatever method they were inlined into
# - the difference between "paintComponent" and "PNG encode inside
# paintComponent", which is the whole question.
#
# The lazy-png-agent javaagent defers Suramadu's ImageConst PNG encode to first
# use of toMessage() rather than doing it unconditionally in the constructor.
# See instrument/lazy-png-agent/.
#
# On by default now, and it was off for a while: it rewrites a third-party class
# at classload, on the path that encodes every frame a player sees, and nothing
# had measured it under play. The A/B that earns it back has been run - same
# build, same scenario, one human seat, only ARENA_LAZY_PNG differing:
#
#   png/deflate samples on the EDT      737  ->  0
#   EDT samples running                1648  ->  740
#   first interaction of a match, p50  361ms ->  49ms
#
# The encode does not move off the thread, it stops happening: the constructor
# encoded every image unconditionally and DrawConstantPool then threw the result
# away whenever the hash already had one. Deferring to toMessage() means a cache
# hit never encodes at all, and with ddImageCacheSize at 16384 nearly every
# image is a hit. That also removes most of a match's warm-up cliff, which is
# the part of the latency a player meets first.
#
# ARENA_LAZY_PNG=0 turns it off, for bisecting a rendering fault against stock
# Suramadu behaviour. The Dockerfile runs HarnessMain against the real
# ImageConst every build, so "it still applies and still defers" is checked
# rather than assumed.
LAZY_PNG="${ARENA_LAZY_PNG:-1}"
PROFILE_VMARGS=""
if [ "$LAZY_PNG" != "0" ]; then
  LAZY_PNG_AGENT="$ARENA_HOME/instrument/lazy-png-agent.jar"
  [ -r "$LAZY_PNG_AGENT" ] || die "lazy-png-agent.jar missing at $LAZY_PNG_AGENT (ARENA_LAZY_PNG=0 runs without it)"
  PROFILE_VMARGS=" -javaagent:$LAZY_PNG_AGENT"
  log "lazy-png-agent on: ImageConst PNG encode deferred to toMessage()"
else
  log "lazy-png-agent off: ImageConst encodes in its constructor, as upstream does"
fi
if [ -n "${ARENA_PROFILE:-}" ] && [ "$ARENA_PROFILE" != "0" ]; then
  AP_SO="$ARENA_HOME/async-profiler/lib/libasyncProfiler.so"
  AP_EVENT="${ARENA_PROFILE_CLIENT_EVENT:-wall}"
  AP_INTERVAL="${ARENA_PROFILE_INTERVAL:-10ms}"
  AP_OUT="$ARENA_STATE/profile-client.collapsed"
  # A missing agent would make the client JVM refuse to start at all, which
  # reads as "the match never loaded". Say why here instead.
  [ -r "$AP_SO" ] || die "ARENA_PROFILE is set but $AP_SO is missing"
  PROFILE_VMARGS="$PROFILE_VMARGS -XX:+UnlockDiagnosticVMOptions -XX:+DebugNonSafepoints"
  PROFILE_VMARGS="$PROFILE_VMARGS -agentpath:$AP_SO=start,event=$AP_EVENT,interval=$AP_INTERVAL,memlimit=128m,collapsed,file=$AP_OUT"
  log "profiling the client JVM: event=$AP_EVENT interval=$AP_INTERVAL -> $AP_OUT"
fi

[ -n "$CLIENT_VMARGS" ] && PROFILE_VMARGS="$PROFILE_VMARGS $CLIENT_VMARGS" \
  && log "extra client vmArgs: $CLIENT_VMARGS"

sed -e "s|@PROFILE_VMARGS@|$PROFILE_VMARGS|g" \
    -e "s|@WEB_FOLDER@|$WEB_FOLDER|g" \
    -e "s|@ARENA_HOME@|$ARENA_HOME|g" \
    -e "s|@MM_HOME@|$MM_HOME|g" \
    -e "s|@JAVA@|$JAVA|g" \
    -e "s|@PORT_MM@|$PORT_MM|g" \
    -e "s|@PLAYER_NAME@|$ARENA_CLIENT_SLOT|g" \
    -e "s|@CLIENT_HEAP@|$CLIENT_HEAP|g" \
    -e "s|@DRAW_DELAY_MS@|$DRAW_DELAY_MS|g" \
    "$ARENA_HOME/config/suramadu.config.template" > "$ARENA_RUN/suramadu/suramadu.config"

# One Suramadu app per line of clients.tsv, at /<did> - a single root-level
# segment, because that is a hard requirement: Suramadu serves HTTP by
# longest prefix, so a nested path renders its page fine, but its WebSocket
# routing only resolves single-segment app paths. /play/<did> answered the
# page and 404'd the socket, which the browser reports as a lost connection
# (verified against the live war: /play/x/async/swing-bin 404s,
# /did:plc:x/async/swing-bin upgrades).
#
# Each app is cloned from the rendered template app with only the path, the
# display name and the login changed - then the template is deleted, so the
# per-identity paths are the only client paths the container serves. Cloned
# with jq rather than kept as templates, so no seat's client can drift from
# another. The DID as the path is what lets headquarters' proxy match the
# caller's identity to the client - a string comparison, no lookup - and
# refuse it every other seat's.
CFG="$ARENA_RUN/suramadu/suramadu.config"
require_cmd jq
# A missing list is a broken init, not an empty match; say which file rather
# than dying on a redirect.
[ -f "$ARENA_RUN/clients.tsv" ] || die "clients.tsv missing; 20-identity.sh did not run"
while IFS="$(printf '\t')" read -r key display; do
  [ -n "$key" ] || continue
  jq --arg key "$key" --arg name "$display" '
    .["/" + $key] = (.["/megamek"]
      | .path = "/" + $key
      | .name = "MegaMek " + $name
      | .swingConfig.launcherConfig.args
          |= sub(" -player_name .*$"; " -player_name " + $name))
  ' "$CFG" > "$CFG.tmp"
  mv "$CFG.tmp" "$CFG"
done < "$ARENA_RUN/clients.tsv"
# A match with no client lines would be a container nobody can reach; the
# template app dying with a loud line beats one that quietly serves the
# wrong login.
jq -e 'keys | map(select(. != "/" and . != "/megamek")) | length > 0' "$CFG" >/dev/null \
  || die "no client path rendered; clients.tsv was empty"
jq 'del(."/megamek")' "$CFG" > "$CFG.tmp"
mv "$CFG.tmp" "$CFG"

sed -e "s|@PORT_WS@|$PORT_WS|g" \
    "$ARENA_HOME/config/jetty.properties.template" > "$ARENA_RUN/suramadu/jetty.properties"

cp "$ARENA_HOME/config/clientsettings.xml.template" "$MM_HOME/mmconf/clientsettings.xml"
# The rules half of the same pair, read by the host rather than the client:
# ScenarioV1 loads mmconf/gameoptions.xml for any scenario that does not name a
# GameOptionsFile of its own. Re-seeded per launch for the same reason
# clientsettings.xml is - a player who opens the game options dialog and
# presses OK makes the client write this file back.
cp "$ARENA_HOME/config/gameoptions.xml.template" "$MM_HOME/mmconf/gameoptions.xml"

# A leftover placeholder means the client would try to log in as "@PLAYER_NAME@"
# and sit in the lobby forever. Easy to catch here, hard to diagnose live.
if grep -q '@[A-Z_]*@' "$ARENA_RUN/suramadu/suramadu.config" "$ARENA_RUN/suramadu/jetty.properties"; then
  die "unsubstituted placeholder left in the rendered config"
fi

log "rendered suramadu config (clients: $(paste -sd' ' < <(awk -F'\t' '{ print "/" $1 "->" $2 }' "$ARENA_RUN/clients.tsv")); web :$PORT_WS, game :$PORT_MM)"