#!/usr/bin/env bash
# run-task.sh — execute exactly one task in a fresh pi context.
#
# A task is the smallest execution unit: a task file inside a phase
# directory (03_api/02_routes.md), a phase's 00_phase.md final pass, or a
# legacy single-file phase.
#
# Usage:
#   run-task.sh                     # next pending task (pipeline order)
#   run-task.sh 03_api/02_routes.md # a specific task (warns if out of order)
#   run-task.sh 03_api/02_routes    # ".md" is added when missing
#
# Env: see SKILL.md (MAX_FIX_ATTEMPTS, PHASE_MODEL, PHASE_THINKING,
#      PHASE_COMMIT, PI_TRUST, FRESH_FIX).
set -uo pipefail
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
source "$SCRIPT_DIR/lib.sh"

# Make interruptions visible: state stays in .agents/phases/todo, and the
# failed executor's session is still resumable on the next run.
trap 'echo; echo "✗ ERROR: interrupted (SIGINT) — ${unit:-this task} is left in $PHASE_TODO/; re-run to continue" >&2; exit 130' INT
trap 'echo; echo "✗ ERROR: interrupted (SIGTERM) — ${unit:-this task} is left in $PHASE_TODO/; re-run to continue" >&2; exit 143' TERM

cd "$(find_root)" || die "no .agents/phases/todo found in this or parent directories (run /to-phase or /audit-create first)"

unit="${1:-}"
if [[ -n "$unit" ]]; then
  [[ "$unit" == *.md ]] || unit="$unit.md"
  [[ -f "$PHASE_TODO/$unit" ]] || die "$unit not found in $PHASE_TODO/"
  first="$(next_unit)"
  if [[ -n "$first" && "$first" != "$unit" ]]; then
    warn "execution order: $first is pending before $unit — running out of order"
  fi
else
  unit="$(next_unit)"
  [[ -n "$unit" ]] || { echo "✓ no pending tasks in $PHASE_TODO/ — project complete."; exit 0; }
fi

build_pi_args
if execute_unit "$unit"; then
  exit 0
fi
# execute_unit printed the failure detail (task failure: errors, logs,
# resume command — or phase-commit failure: the hand-fix command).
echo "✗ ERROR: $unit did not complete — see the error output above" >&2
exit 1