#!/bin/bash
# =============================================================================
# Dolphin controlled startup dependency check
# Runs as ExecStartPre for dolphin-supervisord.service
#
# Checks (in order, with per-step timeouts):
#   1. Docker daemon responsive
#   2. dolphin-hazelcast container healthy (CRITICAL — blocks on failure)
#   3. dolphin-clickhouse container up   (WARN  — ch_writer spools to disk)
#   4. dolphin-prefect container up      (WARN  — exf_fetcher degrades)
#   5. Port-level TCP smoke-test for each
#
# Logs every step with timestamps to:
#   /tmp/dolphin_logs/startup.log          (transient, same dir as BLUE logs)
#   /mnt/dolphinng5_predict/run_logs/dolphin_startup_<date>.log  (persistent)
#
# Exit codes:
#   0  = all critical deps up → supervisord may start
#   1  = critical dep (Hazelcast) timed out → systemd will not start supervisord
# =============================================================================

set -euo pipefail

LOGDIR="/tmp/dolphin_logs"
SUPDIR="${LOGDIR}/supervisor"
TRADEDIR="${LOGDIR}/trader"
RUNLOG="/mnt/dolphinng5_predict/run_logs"
STARTLOG="${LOGDIR}/startup.log"
DATE=$(date -u '+%Y-%m-%d')
PERSISTENT_LOG="${RUNLOG}/dolphin_startup_${DATE}.log"

# ── helpers ─────────────────────────────────────────────────────────────────

ts() { date -u '+%Y-%m-%dT%H:%M:%SZ'; }

log() {
    local msg="[$(ts)] $*"
    echo "$msg"                          # → journald (captured by systemd)
    echo "$msg" >> "$STARTLOG" 2>/dev/null
    echo "$msg" >> "$PERSISTENT_LOG" 2>/dev/null || true
}

log_section() {
    log "────────────────────────────────────────"
    log "$*"
    log "────────────────────────────────────────"
}

tcp_ok() {
    # bash TCP pseudo-device — no nc required
    timeout 2 bash -c "echo >/dev/tcp/${1}/${2}" 2>/dev/null
}

wait_tcp() {
    local label="$1" host="$2" port="$3" timeout_s="${4:-60}"
    local elapsed=0
    log "  Waiting for TCP ${host}:${port} (${label}, timeout=${timeout_s}s)..."
    while ! tcp_ok "$host" "$port"; do
        if (( elapsed >= timeout_s )); then
            log "  TIMEOUT: ${label} not reachable on ${host}:${port} after ${elapsed}s"
            return 1
        fi
        sleep 2; (( elapsed += 2 ))
    done
    log "  OK: ${label} TCP:${port} ready (${elapsed}s)"
    return 0
}

wait_docker_container() {
    local label="$1" name="$2" timeout_s="${3:-90}" require_healthy="${4:-0}"
    local elapsed=0
    log "  Waiting for container '${name}' (timeout=${timeout_s}s)..."
    while true; do
        local status
        status=$(docker inspect --format '{{.State.Status}}' "$name" 2>/dev/null || echo "missing")
        local health
        health=$(docker inspect --format '{{if .State.Health}}{{.State.Health.Status}}{{else}}none{{end}}' "$name" 2>/dev/null || echo "none")

        if [[ "$status" == "running" ]]; then
            if (( require_healthy )) && [[ "$health" != "none" ]] && [[ "$health" != "healthy" ]]; then
                : # keep waiting
            else
                log "  OK: ${label} status=${status} health=${health} (${elapsed}s)"
                return 0
            fi
        fi

        if (( elapsed >= timeout_s )); then
            log "  TIMEOUT: ${label} container '${name}' status=${status} health=${health} after ${elapsed}s"
            return 1
        fi
        sleep 3; (( elapsed += 3 ))
    done
}

# ── create dirs ──────────────────────────────────────────────────────────────

mkdir -p "$SUPDIR" "$TRADEDIR"
# Persistent log dir might not be writable at early boot — ignore failure
mkdir -p "$RUNLOG" 2>/dev/null || true

# ── begin ────────────────────────────────────────────────────────────────────

log_section "=== DOLPHIN STARTUP CHECK BEGIN ==="
log "Host: $(hostname)  Kernel: $(uname -r)"
log "Startup log: ${STARTLOG}"
log "Persistent:  ${PERSISTENT_LOG}"

OVERALL_STATUS="OK"

# ── 1. Docker daemon ─────────────────────────────────────────────────────────

log_section "1/4 Docker daemon"
if ! docker info >/dev/null 2>&1; then
    log "  WARN: Docker daemon not responding — container checks skipped"
    SKIP_CONTAINERS=1
else
    log "  OK: Docker daemon responsive"
    SKIP_CONTAINERS=0
fi

# ── 2. Hazelcast (CRITICAL) ──────────────────────────────────────────────────

log_section "2/4 Hazelcast (CRITICAL)"
HZ_OK=0
if (( SKIP_CONTAINERS )); then
    log "  Docker unavailable — falling back to TCP check only"
else
    if wait_docker_container "dolphin-hazelcast" "dolphin-hazelcast" 90 1; then
        HZ_OK=1
    else
        log "  Container check failed — trying TCP port 5701 directly..."
    fi
fi

if (( ! HZ_OK )); then
    if wait_tcp "Hazelcast" "localhost" 5701 30; then
        HZ_OK=1
    fi
fi

if (( ! HZ_OK )); then
    log "  FATAL: Hazelcast not available after all checks — aborting"
    log "  ACTION: Check 'docker ps' and 'docker logs dolphin-hazelcast'"
    log_section "=== STARTUP ABORTED (Hazelcast unavailable) ==="
    exit 1
fi

# Extra 3s settle time for HZ to finish leader election
sleep 3
log "  HZ settle: 3s"

# ── 3. ClickHouse (WARN) ─────────────────────────────────────────────────────

log_section "3/4 ClickHouse (WARN — ch_writer spools on failure)"
CH_OK=0
if (( ! SKIP_CONTAINERS )); then
    if wait_docker_container "dolphin-clickhouse" "dolphin-clickhouse" 60 0; then
        # Port-level confirm
        if wait_tcp "ClickHouse HTTP" "localhost" 8123 20; then
            CH_OK=1
        fi
    fi
fi
if (( ! CH_OK )); then
    if wait_tcp "ClickHouse HTTP" "localhost" 8123 20; then
        CH_OK=1
    fi
fi
if (( ! CH_OK )); then
    log "  WARN: ClickHouse unreachable — ch_writer will spool; continuing"
    OVERALL_STATUS="DEGRADED"
fi

# ── 4. Prefect (WARN) ────────────────────────────────────────────────────────

log_section "4/4 Prefect (WARN — exf_fetcher degrades gracefully)"
PREFECT_OK=0
if (( ! SKIP_CONTAINERS )); then
    if wait_docker_container "dolphin-prefect" "dolphin-prefect" 45 0; then
        if wait_tcp "Prefect API" "localhost" 4200 20; then
            PREFECT_OK=1
        fi
    fi
fi
if (( ! PREFECT_OK )); then
    if wait_tcp "Prefect API" "localhost" 4200 15; then
        PREFECT_OK=1
    fi
fi
if (( ! PREFECT_OK )); then
    log "  WARN: Prefect unreachable — exf_fetcher may degrade; continuing"
    OVERALL_STATUS="DEGRADED"
fi

# ── summary ──────────────────────────────────────────────────────────────────

log_section "=== STARTUP CHECK COMPLETE ==="
log "  Hazelcast  : $(( HZ_OK ))     (1=OK 0=FAIL)"
log "  ClickHouse : $(( CH_OK ))     (1=OK 0=WARN)"
log "  Prefect    : $(( PREFECT_OK ))     (1=OK 0=WARN)"
log "  Overall    : ${OVERALL_STATUS}"
log "  → Starting supervisord now"
log "  Supervisord conf: /mnt/dolphinng5_predict/prod/supervisor/dolphin-supervisord.conf"
log "  Log dir: ${SUPDIR}"
log "========================================"

# Write a machine-readable status file BLUE can read on startup
cat > "${LOGDIR}/startup_status.json" <<EOF
{
  "ts": "$(ts)",
  "overall": "${OVERALL_STATUS}",
  "hazelcast_ok": $(( HZ_OK )),
  "clickhouse_ok": $(( CH_OK )),
  "prefect_ok": $(( PREFECT_OK )),
  "log": "${STARTLOG}"
}
EOF

exit 0