#!/usr/bin/env bash
# kandev-logs — fetch logs for a running kandev instance by backend port.
#
# Two modes:
#   --export  (default)  GET /api/v1/system/debug/export[?level=LEVEL], pretty
#                        printed with jq. This is the structured in-memory log
#                        buffer + runtime metadata.
#   --tail               Tail the stderr log file written by dev-isolated
#                        (/tmp/kandev-iso-<port>-*/backend.log), or a file given
#                        with --file.
#
# Usage:
#   scripts/kandev-logs <backend_port> [--export] [--level LEVEL]
#   scripts/kandev-logs <backend_port> --tail [--lines N] [--file PATH]
#
# Options:
#   --export          Hit the debug-export endpoint (default).
#   --level LEVEL      Filter export by level. The export endpoint matches the
#                      log entry's level string exactly (zap lowercase levels),
#                      so LEVEL must be one of: debug|info|warn|error|dpanic|
#                      panic|fatal. Passes ?level=LEVEL and prints only .logs.
#   --tail             Tail the backend stderr log file instead of the endpoint.
#   --lines N          Lines to show with --tail (default: 80).
#   --file PATH        Explicit log file for --tail (overrides auto-resolve).
#   -h, --help         Show this help.
#
# Examples:
#   scripts/kandev-logs 48429 --export
#   scripts/kandev-logs 48429 --export --level error
#   scripts/kandev-logs 48429 --tail --lines 120
#
set -euo pipefail

MODE="export"
LEVEL=""
LINES=80
FILE=""
PORT=""

# Levels the export endpoint can match (zapcore.Level.String(), lowercase). The
# endpoint compares the entry's level string exactly, so any other value would
# silently match nothing — we reject it up front instead.
ALLOWED_LEVELS=(debug info warn error dpanic panic fatal)

usage() { sed -n '2,31p' "$0" | sed 's/^# \{0,1\}//'; exit "${1:-2}"; }

while [[ $# -gt 0 ]]; do
  case "$1" in
    --export) MODE="export"; shift ;;
    --tail) MODE="tail"; shift ;;
    --level) LEVEL="${2:?--level requires a value}"; shift 2 ;;
    --lines) LINES="${2:?--lines requires a number}"; shift 2 ;;
    --file) FILE="${2:?--file requires a path}"; shift 2 ;;
    -h|--help) usage 0 ;;
    --*) echo "kandev-logs: unknown flag '$1'" >&2; usage 2 ;;
    *)
      if [[ -z "$PORT" ]]; then PORT="$1"; else
        echo "kandev-logs: unexpected argument '$1'" >&2; usage 2
      fi
      shift
      ;;
  esac
done

[[ -n "$PORT" ]] || { echo "kandev-logs: a backend port is required." >&2; usage 2; }
[[ "$PORT" =~ ^[0-9]+$ ]] || { echo "kandev-logs: port must be numeric, got '$PORT'" >&2; exit 2; }

# Validate --level against the allowed set BEFORE it reaches the URL. An invalid
# value would otherwise be interpolated into ?level= and silently return zero
# matching logs, masking the typo.
if [[ -n "$LEVEL" ]]; then
  level_ok=0
  for lvl in "${ALLOWED_LEVELS[@]}"; do
    [[ "$LEVEL" == "$lvl" ]] && { level_ok=1; break; }
  done
  if [[ "$level_ok" -ne 1 ]]; then
    echo "kandev-logs: invalid --level '$LEVEL'. Allowed: ${ALLOWED_LEVELS[*]}" >&2
    exit 2
  fi
fi

if [[ "$MODE" == "export" ]]; then
  url="http://localhost:$PORT/api/v1/system/debug/export"
  # LEVEL is whitelisted above (alphabetic, no metacharacters), so it is safe to
  # interpolate directly; the query value needs no further encoding.
  [[ -n "$LEVEL" ]] && url="$url?level=$LEVEL"
  if ! body="$(curl -s --fail-with-body "$url" 2>/dev/null)"; then
    echo "kandev-logs: request to $url failed (is the instance on port $PORT up?)" >&2
    exit 1
  fi
  if command -v jq >/dev/null 2>&1; then
    if [[ -n "$LEVEL" ]]; then
      printf '%s' "$body" | jq '.logs'
    else
      printf '%s' "$body" | jq .
    fi
  else
    printf '%s\n' "$body"
  fi
  exit 0
fi

# --- tail mode ---
if [[ -z "$FILE" ]]; then
  # Resolve the dev-isolated log convention: /tmp/kandev-iso-<port>-*/backend.log
  # Pick the most recent match.
  FILE="$(ls -t /tmp/kandev-iso-"$PORT"-*/backend.log 2>/dev/null | head -1 || true)"
fi
[[ -n "$FILE" && -f "$FILE" ]] || {
  echo "kandev-logs: no log file found for port $PORT. Pass --file PATH." >&2
  exit 1
}
echo "kandev-logs: tail -n $LINES $FILE" >&2
tail -n "$LINES" "$FILE"