#!/bin/sh
# planning-with-files: set the status of one phase in task_plan.md (v3).
#
# This is the ONLY sanctioned concurrent-safe writer of task_plan.md status
# lines. The orchestrator owns task_plan.md; workers NEVER edit it directly.
# All status edits go through this read-modify-write under an advisory flock on
# the <plan-dir>/.write_lock sentinel, with an atomic temp-file + mv swap so a
# torn write can never leave a half-rewritten plan on disk (architecture C4).
#
# Note: editing task_plan.md changes its SHA, so the orchestrator must
# re-attest at phase boundaries (see attest-plan.sh).
#
# Plan-dir resolution (via resolve-plan-dir.sh):
#   1. $PLAN_ID env var -> ./.planning/$PLAN_ID/
#   2. ./.planning/.active_plan
#   3. Newest ./.planning/<dir>/ by mtime
#   4. Legacy: project root ./task_plan.md
#
# Usage:
#   sh scripts/phase-status.sh <phase-number> <pending|in_progress|complete>
#
# Exits 1 with a message if the phase does not exist or the status is invalid.

set -u

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
RESOLVER="${SCRIPT_DIR}/resolve-plan-dir.sh"

usage() {
    printf "Usage: %s <phase-number> <pending|in_progress|complete>\n" "$0" >&2
}

resolve_plan_file() {
    plan_dir=""
    if [ -f "${RESOLVER}" ]; then
        plan_dir="$(sh "${RESOLVER}" 2>/dev/null)"
    fi
    if [ -n "${plan_dir}" ] && [ -f "${plan_dir}/task_plan.md" ]; then
        printf "%s\n" "${plan_dir}/task_plan.md"
        return 0
    fi
    if [ -f "./task_plan.md" ]; then
        printf "%s\n" "./task_plan.md"
        return 0
    fi
    return 1
}

PHASE_NUM="${1:-}"
NEW_STATUS="${2:-}"

if [ -z "${PHASE_NUM}" ] || [ -z "${NEW_STATUS}" ]; then
    usage
    exit 1
fi

# Validate phase number is a positive integer.
case "${PHASE_NUM}" in
    ''|*[!0-9]*)
        printf "[phase-status] phase number must be a positive integer, got '%s'.\n" "${PHASE_NUM}" >&2
        exit 1
        ;;
esac

# Validate status value against the allowlist.
case "${NEW_STATUS}" in
    pending|in_progress|complete) : ;;
    *)
        printf "[phase-status] invalid status '%s' (allowed: pending, in_progress, complete).\n" "${NEW_STATUS}" >&2
        exit 1
        ;;
esac

PLAN_FILE="$(resolve_plan_file)" || {
    printf "[phase-status] No task_plan.md found. Create a plan first.\n" >&2
    exit 1
}

PLAN_DIR="$(dirname "${PLAN_FILE}")"
LOCK_FILE="${PLAN_DIR}/.write_lock"

# Confirm the phase heading exists before touching the file.
if ! grep -q "### Phase ${PHASE_NUM}\b" "${PLAN_FILE}" 2>/dev/null; then
    # Fall back to a looser match for headings like "### Phase 1:" where \b may
    # not be honored by a minimal grep.
    if ! grep -Eq "^### Phase ${PHASE_NUM}([^0-9]|$)" "${PLAN_FILE}" 2>/dev/null; then
        printf "[phase-status] Phase %s not found in %s.\n" "${PHASE_NUM}" "${PLAN_FILE}" >&2
        exit 1
    fi
fi

# Rewrite only the FIRST "**Status:**" line that follows the "### Phase N"
# heading. awk tracks whether we are inside the target phase block; once we
# rewrite its status line we stop matching so later phases are untouched.
rewrite() {
    src="$1"
    dst="$2"
    awk -v target="${PHASE_NUM}" -v newstatus="${NEW_STATUS}" '
        BEGIN { in_block = 0; done = 0 }
        {
            line = $0
            if (line ~ /^### Phase /) {
                # Extract the phase number right after "### Phase ".
                rest = line
                sub(/^### Phase /, "", rest)
                num = rest
                sub(/[^0-9].*$/, "", num)
                if (num == target && done == 0) {
                    in_block = 1
                } else {
                    in_block = 0
                }
            } else if (in_block == 1 && done == 0 && line ~ /\*\*Status:\*\*/) {
                # Preserve leading whitespace/bullet before "**Status:**".
                prefix = line
                sub(/\*\*Status:\*\*.*$/, "", prefix)
                line = prefix "**Status:** " newstatus
                in_block = 0
                done = 1
            }
            print line
        }
        END { if (done == 0) exit 3 }
    ' "${src}" > "${dst}"
}

TMP_FILE="${PLAN_FILE}.tmp.$$"

do_write() {
    if ! rewrite "${PLAN_FILE}" "${TMP_FILE}"; then
        rm -f "${TMP_FILE}" 2>/dev/null
        printf "[phase-status] No **Status:** line found for Phase %s.\n" "${PHASE_NUM}" >&2
        return 1
    fi
    mv -f "${TMP_FILE}" "${PLAN_FILE}"
    return 0
}

rc=0
if command -v flock >/dev/null 2>&1; then
    (
        flock -w 5 9 || true
        do_write
    ) 9>"${LOCK_FILE}" 2>/dev/null
    rc=$?
    rm -f "${LOCK_FILE}" 2>/dev/null || true
else
    do_write
    rc=$?
fi

if [ "${rc}" -ne 0 ]; then
    rm -f "${TMP_FILE}" 2>/dev/null
    exit 1
fi

printf "[phase-status] Phase %s -> %s in %s\n" "${PHASE_NUM}" "${NEW_STATUS}" "${PLAN_FILE}"
exit 0