#!/usr/bin/env bash
# ship-it AFK loop — works through every ready issue end-to-end.
# See SKILL.md for design. Ctrl-C to stop; partial work is preserved on disk.

set -uo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
REPO_ROOT="$(git rev-parse --show-toplevel 2>/dev/null)" || { echo "not in a git repo"; exit 1; }

# ---- config (env-overridable) ----
MAX_ITERATIONS="${SHIP_IT_MAX:-50}"
MAX_CONSECUTIVE_FAILURES="${SHIP_IT_MAX_FAIL:-3}"
TRUNK_BRANCH="${SHIP_IT_TRUNK:-main}"
ITERATION_TIMEOUT="${SHIP_IT_TIMEOUT:-30m}"   # per-issue cap
LOG_DIR="${SHIP_IT_LOG_DIR:-$REPO_ROOT/.ship-it-logs}"

mkdir -p "$LOG_DIR"
RUN_ID="$(date -u +%Y%m%dT%H%M%SZ)"
LOG_FILE="$LOG_DIR/run-$RUN_ID.log"

# ---- logging ----
log() {
  local ts; ts="$(date -u +%H:%M:%S)"
  printf '[%s] %s\n' "$ts" "$*" | tee -a "$LOG_FILE"
}
die() { log "FATAL: $*"; exit 1; }

# ---- graceful interrupt ----
INTERRUPTED=0
on_interrupt() {
  INTERRUPTED=1
  log ""
  log "interrupt received — finishing current step cleanly, then stopping"
}
trap on_interrupt INT

# ---- tracker detection ----
ORIGIN_URL="$(git -C "$REPO_ROOT" remote get-url origin 2>/dev/null || true)"
if [[ "$ORIGIN_URL" == *"github.com"* ]]; then
  TRACKER_CLI="gh"
  command -v gh >/dev/null || die "gh CLI not installed"
  gh auth status >/dev/null 2>&1 || die "gh not authenticated (run: gh auth login)"
  list_ready_issues() {
    gh issue list --state open --label slice --limit 100 \
      --json number,title,labels \
      --jq '[.[] | select(.labels | map(.name) | (contains(["blocked"]) or contains(["needs-decision"]) or contains(["ci-failed"])) | not)] | sort_by(.number)'
  }
elif [[ "$ORIGIN_URL" == *"gitea"* ]]; then
  TRACKER_CLI="tea"
  command -v tea >/dev/null || die "tea CLI not installed (Gitea repo detected) — install tea or switch to a GitHub remote"
  list_ready_issues() {
    tea issues list --state open --output json 2>/dev/null \
      | jq '[.[] | select((.labels // []) | map(.name) | (contains(["blocked"]) or contains(["needs-decision"]) or contains(["ci-failed"])) | not) | select((.labels // []) | map(.name) | contains(["slice"]))] | sort_by(.index)'
  }
else
  die "unknown tracker for origin: '$ORIGIN_URL' (need github.com or gitea.*)"
fi

# ---- preflight ----
cd "$REPO_ROOT"
[[ -z "$(git status --porcelain)" ]] || die "git tree is dirty — commit or stash before starting"
CURRENT_BRANCH="$(git branch --show-current)"
[[ "$CURRENT_BRANCH" == "$TRUNK_BRANCH" ]] || die "not on $TRUNK_BRANCH (on '$CURRENT_BRANCH')"
git fetch origin "$TRUNK_BRANCH" >/dev/null 2>&1 || die "git fetch failed"
LOCAL_SHA="$(git rev-parse HEAD)"
REMOTE_SHA="$(git rev-parse "origin/$TRUNK_BRANCH")"
[[ "$LOCAL_SHA" == "$REMOTE_SHA" ]] || die "$TRUNK_BRANCH not up-to-date with origin (pull first)"
command -v claude >/dev/null || die "claude CLI not on PATH"

# ---- banner ----
log "ship-it run $RUN_ID"
log "  tracker:  $TRACKER_CLI ($ORIGIN_URL)"
log "  trunk:    $TRUNK_BRANCH @ ${LOCAL_SHA:0:8}"
log "  log:      $LOG_FILE"
log "  config:   max_iter=$MAX_ITERATIONS, max_fail=$MAX_CONSECUTIVE_FAILURES, timeout=$ITERATION_TIMEOUT"
log ""

ITERATE_PROMPT_TEMPLATE="$(cat "$SCRIPT_DIR/iterate.md")"
SHIPPED=()
FAILED=()
NEEDS_DECISION=()
CONSECUTIVE_FAILURES=0
ITERATION=0

# ---- main loop ----
while (( ITERATION < MAX_ITERATIONS )); do
  (( INTERRUPTED )) && break
  ITERATION=$((ITERATION + 1))

  READY_JSON="$(list_ready_issues 2>/dev/null || echo '[]')"
  READY_COUNT="$(echo "$READY_JSON" | jq 'length' 2>/dev/null || echo 0)"

  if (( READY_COUNT == 0 )); then
    log "backlog empty — stopping"
    break
  fi

  ISSUE_NUM="$(echo "$READY_JSON" | jq -r '.[0].number // .[0].index')"
  ISSUE_TITLE="$(echo "$READY_JSON" | jq -r '.[0].title')"

  log "─────────────────────────────────────────────────────────────"
  log "iter $ITERATION | #$ISSUE_NUM \"$ISSUE_TITLE\" ($READY_COUNT ready) → starting"

  ITER_LOG="$LOG_DIR/iter-$RUN_ID-$ISSUE_NUM.log"
  PROMPT="$ITERATE_PROMPT_TEMPLATE

## Variables for this iteration
- ISSUE_NUMBER=$ISSUE_NUM
- TRACKER_CLI=$TRACKER_CLI
- TRUNK_BRANCH=$TRUNK_BRANCH
- REPO_ROOT=$REPO_ROOT

Begin."

  ITER_START="$(date +%s)"
  set +e
  timeout "$ITERATION_TIMEOUT" claude -p "$PROMPT" \
    --allowed-tools "Bash,Edit,Write,Read,Grep,Glob,WebFetch" \
    --output-format text \
    >"$ITER_LOG" 2>&1
  CLAUDE_EXIT=$?
  set -e
  ITER_END="$(date +%s)"
  ITER_DURATION=$((ITER_END - ITER_START))

  RESULT_LINE="$(grep -E '^ITERATION_RESULT:' "$ITER_LOG" | tail -1 || true)"
  STATUS="$(echo "$RESULT_LINE" | sed -n 's/.*status=\([^ ]*\).*/\1/p')"
  PR_FIELD="$(echo "$RESULT_LINE" | sed -n 's/.*pr=\([^ ]*\).*/\1/p')"
  REASON="$(echo "$RESULT_LINE" | sed -n 's/.*reason=\(.*\)/\1/p')"

  if (( CLAUDE_EXIT == 124 )); then
    STATUS="failed"
    REASON="timeout after $ITERATION_TIMEOUT"
  fi

  case "$STATUS" in
    shipped)
      log "iter $ITERATION | #$ISSUE_NUM ✓ shipped → PR $PR_FIELD (${ITER_DURATION}s)"
      SHIPPED+=("#$ISSUE_NUM→$PR_FIELD")
      CONSECUTIVE_FAILURES=0
      ;;
    failed)
      log "iter $ITERATION | #$ISSUE_NUM ✗ failed: $REASON (${ITER_DURATION}s, see $ITER_LOG)"
      FAILED+=("#$ISSUE_NUM ($REASON)")
      CONSECUTIVE_FAILURES=$((CONSECUTIVE_FAILURES + 1))
      ;;
    needs-decision)
      log "iter $ITERATION | #$ISSUE_NUM ? needs-decision: $REASON (${ITER_DURATION}s)"
      NEEDS_DECISION+=("#$ISSUE_NUM ($REASON)")
      CONSECUTIVE_FAILURES=0
      ;;
    *)
      log "iter $ITERATION | #$ISSUE_NUM ! unknown outcome (claude exit=$CLAUDE_EXIT, ${ITER_DURATION}s) — see $ITER_LOG"
      FAILED+=("#$ISSUE_NUM (unknown outcome)")
      CONSECUTIVE_FAILURES=$((CONSECUTIVE_FAILURES + 1))
      ;;
  esac

  if (( CONSECUTIVE_FAILURES >= MAX_CONSECUTIVE_FAILURES )); then
    log "$MAX_CONSECUTIVE_FAILURES consecutive failures — stopping for human review"
    break
  fi

  # back to trunk for next iteration
  if [[ "$(git branch --show-current)" != "$TRUNK_BRANCH" ]]; then
    git switch "$TRUNK_BRANCH" >/dev/null 2>&1 || log "  warn: could not return to $TRUNK_BRANCH"
  fi
  git pull --ff-only origin "$TRUNK_BRANCH" >/dev/null 2>&1 || log "  warn: could not fast-forward $TRUNK_BRANCH"
done

# ---- summary ----
log ""
log "==== ship-it summary ===="
log "iterations:     $ITERATION"
log "shipped:        ${#SHIPPED[@]} ${SHIPPED[*]:-}"
log "failed:         ${#FAILED[@]} ${FAILED[*]:-}"
log "needs-decision: ${#NEEDS_DECISION[@]} ${NEEDS_DECISION[*]:-}"
log "log:            $LOG_FILE"

if (( INTERRUPTED )); then
  log "stop reason:    user-interrupt"
  exit 130
elif (( CONSECUTIVE_FAILURES >= MAX_CONSECUTIVE_FAILURES )); then
  log "stop reason:    consecutive-failures"
  exit 1
else
  log "stop reason:    backlog-empty"
  exit 0
fi