#!/bin/bash
# triple-c-task-runner — Executes a scheduled task via Claude Code agent
# Called by cron with a task ID argument. Handles locking, logging,
# notifications, one-time task cleanup, and log pruning.

set -uo pipefail

SCHEDULER_DIR="${HOME}/.claude/scheduler"
TASKS_DIR="${SCHEDULER_DIR}/tasks"
LOGS_DIR="${SCHEDULER_DIR}/logs"
NOTIFICATIONS_DIR="${SCHEDULER_DIR}/notifications"
RUNNING_DIR="${SCHEDULER_DIR}/running"
ENV_FILE="${SCHEDULER_DIR}/.env"

TASK_ID="${1:-}"

if [ -z "$TASK_ID" ]; then
    echo "Usage: triple-c-task-runner <task-id>" >&2
    exit 1
fi

TASK_FILE="${TASKS_DIR}/${TASK_ID}.json"
LOCK_FILE="${SCHEDULER_DIR}/.lock-${TASK_ID}"

if [ ! -f "$TASK_FILE" ]; then
    echo "Task file not found: $TASK_FILE" >&2
    exit 1
fi

# ── Acquire lock (prevent overlapping runs of the same task) ─────────────────
exec 200>"$LOCK_FILE"
if ! flock -n 200; then
    echo "Task $TASK_ID is already running, skipping." >&2
    exit 0
fi

# ── Source saved environment ─────────────────────────────────────────────────
# The env file is a snapshot taken by the entrypoint, which runs as root. A
# snapshot written before the entrypoint stopped capturing HOME still carries
# HOME=/root, and `set -a` would apply it to `claude` below — which then finds no
# credential under /root/.claude and exits with "Not logged in". The env file
# lives on the home volume, so those stale copies outlive an image update until
# the container is restarted; keep our own HOME regardless of what it says.
if [ -f "$ENV_FILE" ]; then
    REAL_HOME="${HOME:-/home/claude}"
    set -a
    # shellcheck disable=SC1090
    source "$ENV_FILE"
    set +a
    HOME="$REAL_HOME"
fi

# ── Read task definition ────────────────────────────────────────────────────
PROMPT=$(jq -r '.prompt' "$TASK_FILE")
WORKING_DIR=$(jq -r '.working_dir // "/workspace"' "$TASK_FILE")
TASK_NAME=$(jq -r '.name' "$TASK_FILE")
TASK_TYPE=$(jq -r '.type' "$TASK_FILE")

# ── Resolve permission mode ─────────────────────────────────────────────────
# TRIPLE_C_PERMISSION_MODE is injected into the container by Triple-C from the
# project's permission setting. Keep this mapping in sync with
# PermissionMode::cli_args() in app/src-tauri/src/models/project.rs.
# NOTE: headless `claude -p` runs cannot answer a permission prompt, so any
# mode other than "bypass" means the task may stop early when Claude Code asks
# for permission. Unset or unrecognized values pass no flag (Claude's default).
PERMISSION_ARGS=()
case "${TRIPLE_C_PERMISSION_MODE:-}" in
    plan)        PERMISSION_ARGS=(--permission-mode plan) ;;
    acceptEdits) PERMISSION_ARGS=(--permission-mode acceptEdits) ;;
    bypass)      PERMISSION_ARGS=(--dangerously-skip-permissions) ;;
    *)           PERMISSION_ARGS=() ;;
esac

# ── Prepare log directory ───────────────────────────────────────────────────
TASK_LOG_DIR="${LOGS_DIR}/${TASK_ID}"
mkdir -p "$TASK_LOG_DIR"

TIMESTAMP=$(date +"%Y%m%d-%H%M%S")
LOG_FILE="${TASK_LOG_DIR}/${TIMESTAMP}.log"

# ── Publish run state ───────────────────────────────────────────────────────
# A scheduled run is detached — cron has no terminal, and the app fires it as a
# detached exec — so without this there is no way to tell a task that is still
# thinking from one that died, and a long run reads as a stall. `list`, `status`
# and the app's Automation tab all read this file.
#
# flock above is what actually prevents overlapping runs; this is purely an
# observability record, which is why readers verify the pid rather than trust
# the file. The EXIT trap covers the crash paths (OOM, container stop, SIGTERM)
# that would otherwise leave a task looking like it had been running for days.
mkdir -p "$RUNNING_DIR"
RUN_STATE="${RUNNING_DIR}/${TASK_ID}.json"
trap 'rm -f "$RUN_STATE"' EXIT
jq -n \
    --arg pid "$$" \
    --arg started "$(date +%s)" \
    --arg log "$LOG_FILE" \
    --arg name "$TASK_NAME" \
    '{pid: ($pid | tonumber), started_epoch: ($started | tonumber), log: $log, name: $name}' \
    > "$RUN_STATE"

# ── Execute Claude agent ────────────────────────────────────────────────────
{
    echo "=== Task: $TASK_NAME ($TASK_ID) ==="
    echo "=== Started: $(date) ==="
    echo "=== Working dir: $WORKING_DIR ==="
    echo "=== Prompt: $PROMPT ==="
    echo "=== Permission mode: ${TRIPLE_C_PERMISSION_MODE:-default} ==="
    echo ""
} > "$LOG_FILE"

EXIT_CODE=0
if [ -d "$WORKING_DIR" ]; then
    cd "$WORKING_DIR"
    # ${arr[@]+"${arr[@]}"} keeps an empty array safe under `set -u`
    claude -p "$PROMPT" ${PERMISSION_ARGS[@]+"${PERMISSION_ARGS[@]}"} >> "$LOG_FILE" 2>&1 || EXIT_CODE=$?
else
    echo "Error: working directory '$WORKING_DIR' does not exist" >> "$LOG_FILE"
    EXIT_CODE=1
fi

{
    echo ""
    echo "=== Finished: $(date) ==="
    echo "=== Exit code: $EXIT_CODE ==="
} >> "$LOG_FILE"

# ── Cap the size of this run's log ──────────────────────────────────────────
# `claude -p` output is unbounded — a task told to walk a large tree can emit
# hundreds of megabytes in one run — and the pruning below counts *files*, not
# bytes, so twenty logs of any size are twenty logs. One chatty task can
# therefore fill the home volume, which is also where ~/.claude and the OAuth
# credential live.
#
# The tail is the half worth keeping: `claude -p` writes its answer at the end,
# and the footer just appended carries the exit code that `status` and the app
# both grep for. So an oversize log is rewritten as a marker line plus its last
# MAX_LOG_BYTES rather than being deleted or capped from the front. This runs
# before the notification below so the summary is taken from the capped file.
#
# Best effort throughout: the run's real result is already recorded, so a
# failure here must not change the exit status. Note that `run` may be tailing
# this file — it has already streamed everything up to here, and nothing is
# appended after this point, so replacing the inode is invisible to it.
MAX_LOG_BYTES=$(( 5 * 1024 * 1024 ))
LOG_BYTES=$(wc -c < "$LOG_FILE" 2>/dev/null || echo 0)
if [ "${LOG_BYTES:-0}" -gt "$MAX_LOG_BYTES" ]; then
    TRUNC_FILE="${LOG_FILE}.trunc"
    if {
        echo "=== Log truncated: $(( LOG_BYTES - MAX_LOG_BYTES )) bytes dropped from the start (cap ${MAX_LOG_BYTES} bytes) ==="
        tail -c "$MAX_LOG_BYTES" "$LOG_FILE"
    } > "$TRUNC_FILE" 2>/dev/null; then
        mv -f "$TRUNC_FILE" "$LOG_FILE" 2>/dev/null || rm -f "$TRUNC_FILE"
    else
        rm -f "$TRUNC_FILE"
    fi
fi

# ── Write notification ──────────────────────────────────────────────────────
mkdir -p "$NOTIFICATIONS_DIR"
NOTIFY_FILE="${NOTIFICATIONS_DIR}/${TASK_ID}_${TIMESTAMP}.notify"

if [ $EXIT_CODE -eq 0 ]; then
    STATUS="SUCCESS"
else
    STATUS="FAILED (exit code $EXIT_CODE)"
fi

# Extract a summary (last 10 meaningful lines before the footer)
SUMMARY=$(grep -v "^===" "$LOG_FILE" | grep -v "^$" | tail -n 10)

cat > "$NOTIFY_FILE" <<NOTIFY
Task:    $TASK_NAME ($TASK_ID)
Status:  $STATUS
Time:    $(date)
Type:    $TASK_TYPE

Summary:
$SUMMARY
NOTIFY

# ── One-time task cleanup ───────────────────────────────────────────────────
if [ "$TASK_TYPE" = "once" ]; then
    rm -f "$TASK_FILE"
    # Rebuild crontab to remove the completed one-time task
    /usr/local/bin/triple-c-scheduler list > /dev/null 2>&1 || true
    # Direct crontab rebuild (in case scheduler list doesn't trigger it)
    TMP_CRON=$(mktemp)
    echo "# Triple-C scheduled tasks — managed by triple-c-scheduler" > "$TMP_CRON"
    echo "# Do not edit manually; changes will be overwritten." >> "$TMP_CRON"
    echo "" >> "$TMP_CRON"
    for tf in "$TASKS_DIR"/*.json; do
        [ -f "$tf" ] || continue
        local_enabled=$(jq -r '.enabled' "$tf")
        [ "$local_enabled" = "true" ] || continue
        local_schedule=$(jq -r '.schedule' "$tf")
        local_id=$(jq -r '.id' "$tf")
        echo "$local_schedule /usr/local/bin/triple-c-task-runner $local_id" >> "$TMP_CRON"
    done
    crontab "$TMP_CRON" 2>/dev/null || true
    rm -f "$TMP_CRON"
fi

# ── Prune old logs (keep 20 per task) ───────────────────────────────────────
LOG_COUNT=$(find "$TASK_LOG_DIR" -name "*.log" -type f 2>/dev/null | wc -l)
if [ "$LOG_COUNT" -gt 20 ]; then
    find "$TASK_LOG_DIR" -name "*.log" -type f | sort | head -n $((LOG_COUNT - 20)) | xargs rm -f
fi

# ── Reap log dirs of tasks that no longer exist ─────────────────────────────
# `triple-c-scheduler remove` deletes a task's log dir with the task, but a
# one-time task deletes its own task file above, so `remove` can never be run
# for it — nothing knows the id any more — and its directory would sit on the
# home volume forever. This is the sweep for that case.
#
# Deliberately delayed rather than done in the cleanup above: the run that just
# finished has only just written the sole record of itself, `run` and the app's
# Automation tab may still be tailing it, and `logs --id` keeps working for a
# task whose file is gone. So a dir is reaped only once nothing in it has been
# touched for LOG_RETENTION_DAYS, and never while a run is publishing state for
# that id. The sweep rides on task runs, so a container whose only task was
# one-time keeps that one directory until something else runs.
#
# Same paranoia as reap_task_logs() in triple-c-scheduler: the id comes from a
# directory name and is re-validated before it is used to build an `rm -rf`
# path, so no empty or path-bearing name can reach beyond $LOGS_DIR.
LOG_RETENTION_DAYS=7
for ORPHAN_DIR in "$LOGS_DIR"/*/; do
    [ -d "$ORPHAN_DIR" ] || continue
    ORPHAN_ID=$(basename "$ORPHAN_DIR")
    [[ "$ORPHAN_ID" =~ ^[A-Za-z0-9][A-Za-z0-9_-]*$ ]] || continue
    [ -f "${TASKS_DIR}/${ORPHAN_ID}.json" ] && continue
    [ -f "${RUNNING_DIR}/${ORPHAN_ID}.json" ] && continue
    # Anything modified inside the window keeps the whole directory.
    [ -n "$(find "$ORPHAN_DIR" -mmin "-$(( LOG_RETENTION_DAYS * 1440 ))" -print -quit 2>/dev/null)" ] && continue
    rm -rf -- "${LOGS_DIR:?}/${ORPHAN_ID}"
done

# ── Prune old notifications (keep 50 total) ─────────────────────────────────
NOTIFY_COUNT=$(find "$NOTIFICATIONS_DIR" -name "*.notify" -type f 2>/dev/null | wc -l)
if [ "$NOTIFY_COUNT" -gt 50 ]; then
    find "$NOTIFICATIONS_DIR" -name "*.notify" -type f | sort | head -n $((NOTIFY_COUNT - 50)) | xargs rm -f
fi

# Release lock
flock -u 200
rm -f "$LOCK_FILE"

exit $EXIT_CODE