#!/usr/bin/env bash
# Reference copy of Thiago Amaro's Claude Code harness, served next to the hackathon write-up.
# What it is: opens a named zellij tab running interactive Claude Code with a hand-off briefing as its first prompt.
# Last changed 2026-08-10 (last commit in the author's dotfiles history). The code below is unchanged in this copy.
# Provided as-is, without warranty. Paths, the ledger file and the tab-status hook belong to the author's own setup.
# kickoff-session.sh - spawn a visible zellij tab running Claude Code with a kickoff prompt.
# Usage: kickoff-session.sh <project-dir> <prompt-file> [tab-name] [extra claude args...]
# The prompt file is read in THIS shell and passed as a single argv element, so
# multiline prompts survive zellij -> claude intact.
# A watch-agents pane (live subagent transcripts) is opt-in: set KICKOFF_WATCH=1
# to attach it below the session (disabled by default 2026-07-27; redundant while
# working inside Claude Code).
set -euo pipefail

die() { echo "kickoff-session: $*" >&2; exit 1; }

[ $# -ge 2 ] || die "usage: kickoff-session.sh <project-dir> <prompt-file> [tab-name] [extra claude args...]"

PROJECT_DIR=$1
PROMPT_FILE=$2
shift 2

# Optional tab name: next arg, unless it looks like a flag.
if [ $# -ge 1 ] && [ "${1#-}" = "$1" ]; then
  TAB_NAME=$1
  shift
else
  TAB_NAME=$(basename "$PROJECT_DIR")
fi

[ -n "${ZELLIJ_SESSION_NAME:-}" ] || die "not inside a zellij session; run manually: cd '$PROJECT_DIR' && claude \"\$(cat '$PROMPT_FILE')\""
[ -d "$PROJECT_DIR" ] || die "project dir not found: $PROJECT_DIR"
[ -s "$PROMPT_FILE" ] || die "prompt file missing or empty: $PROMPT_FILE"

# Staleness guard: a handoff titled after a ledger item (e.g. "# LEV-7 Finish: ...")
# must not spawn if that row is already DONE/DISCARDED - it means an earlier session
# consumed the handoff (LEV-7 replay, 2026-07-28). Only the TITLE line is checked so
# body mentions like "LEV-1..5 DONE" never false-positive. KICKOFF_FORCE=1 overrides.
LEDGER="$HOME/Library/Mobile Documents/iCloud~md~obsidian/Documents/Claude/docs/master-roadmap_ledger_v1.md"
if [ -z "${KICKOFF_FORCE:-}" ] && [ -f "$LEDGER" ]; then
  TITLE=$(grep -m1 '^#' "$PROMPT_FILE" || true)
  for ID in $(printf '%s\n' "$TITLE" | grep -oE '[A-Z][A-Z0-9]*-[0-9]+' | sort -u); do
    STATUS=$(grep -m1 -E "^\| $ID \|" "$LEDGER" | awk -F'|' '{gsub(/ /,"",$4); print $4}')
    case "$STATUS" in
      DONE|DISCARDED) die "stale handoff: ledger row $ID is already $STATUS (set KICKOFF_FORCE=1 to spawn anyway)";;
    esac
  done
fi

# zellij command-panes exec the binary directly (no login shell), so resolve claude now.
# Per-machine layouts differ (2026-08-10): the Mini's ONE real install is the native
# ~/.local/bin/claude (its Homebrew copy lagged stale and was removed); the Air has
# ONLY the Homebrew copy. Prefer native when present, else PATH, then PROBE the
# resolved binary: the historical failure mode is a stale copy that hangs at startup
# with 0% CPU, which a spawned tab shows as silence - die loudly here instead.
CLAUDE_BIN="$HOME/.local/bin/claude"
[ -x "$CLAUDE_BIN" ] || CLAUDE_BIN=$(command -v claude) || die "claude not found in PATH"
timeout 15 "$CLAUDE_BIN" --version >/dev/null 2>&1 \
  || die "claude at $CLAUDE_BIN is unresponsive (--version hung or failed); stale install?"

# KICKOFF_TAB marks the spawned claude as a kickoff session; the
# kickoff-tab-status.sh hook uses it to rename this tab by session state.
# --name makes the session addressable via SendMessage/ListAgents by the tab
# slug. crossSessionInbound=accept lets a conductor session message this tab
# without a held-message dialog: the spawn runs bypassPermissions, and a bypass
# receiver holds messages from non-bypass senders by default (claude >= 2.1.224;
# both flags parse on older versions, messaging just stays off).
TAB_ID=$(zellij action new-tab --cwd "$PROJECT_DIR" --name "$TAB_NAME" -- \
  /usr/bin/env "KICKOFF_TAB=$TAB_NAME" \
  "$CLAUDE_BIN" --permission-mode bypassPermissions --name "$TAB_NAME" \
  --settings '{"crossSessionInbound":"accept"}' "$@" "$(cat "$PROMPT_FILE")")

# Sidecar: the tab's stable ID for the status hook. Unqualified rename-tab
# targets whatever tab has FOCUS (verified 2026-07-28, zellij 0.44.3); only
# rename-tab -t <id> is safe from a background tab, and the id is only known
# here, after new-tab returns - the spawned env can't carry it.
mkdir -p "$HOME/.claude/kickoff-tabs"
printf '%s\n' "$TAB_ID" > "$HOME/.claude/kickoff-tabs/$TAB_NAME.id"

echo "spawned tab '$TAB_NAME' (id $TAB_ID) in $PROJECT_DIR with prompt $PROMPT_FILE"

# Watcher pane: live subagent transcripts under the new session (new-tab focuses
# the new tab, so the pane lands there). The until-loop covers the race where the
# project has no session transcript yet - watch-agents exits nonzero until the
# spawned claude writes its first JSONL, then attaches and follows it.
WATCH_BIN="$HOME/.claude/scripts/watch-agents"
if [ -n "${KICKOFF_WATCH:-}" ] && [ -x "$WATCH_BIN" ]; then
  zellij action new-pane --direction down --cwd "$PROJECT_DIR" -- \
    /bin/bash -c "until '$WATCH_BIN' --project '$PROJECT_DIR'; do sleep 2; done"
  echo "watcher pane attached (KICKOFF_WATCH=1 requested)"
fi