#!/usr/bin/env bash
# pr-resolve — list and resolve PR review threads in batch.
#
# Usage:
#   scripts/pr-resolve list <PR>
#       List unresolved review threads, one per line, TAB-separated:
#         <thread_id>\t<comment_id>\t<author>\t<path>\t<body_first_120_chars>
#
#   scripts/pr-resolve show <PR> <thread_id|comment_id>
#       Print the full thread/comment body plus path, line, author, commit id,
#       and URL. Use before deciding how to answer a preview from list.
#
#   scripts/pr-resolve reopen <PR> <thread_id>
#       Reopen an already-resolved review thread after an authorized later
#       change invalidates its resolution rationale.
#
#   scripts/pr-resolve reply <PR> <comment_id> <thread_id> <body>
#   scripts/pr-resolve reply <PR> <comment_id> <thread_id> --body-file <path>
#       Reply to the thread starter, resolve the thread, and add a +1
#       reaction in one call. Use this for both "fixed" replies and
#       pushback replies — the reply body conveys whether you agreed
#       or not.
#
# Owner/repo are derived from `gh repo view` in the current repo.
#
# Requires: gh (authenticated) and jq.

set -euo pipefail

usage() {
  sed -n '2,20p' "$0" | sed 's|^# \{0,1\}||'
  exit "${1:-1}"
}

[ $# -ge 1 ] || usage

cmd=$1; shift

case "$cmd" in
  -h | --help | help)
    usage 0
    ;;
esac

if [[ "$cmd" == "reply" && ( $# -eq 4 || $# -eq 5 ) ]]; then
  if [[ "$2" == PRRT_* ]]; then
    echo "reply expects comment_id before thread_id; got a review thread ID in the comment_id position" >&2
    exit 1
  fi
  if [[ "$3" != PRRT_* ]]; then
    echo "reply expects thread_id after comment_id; got a non-review-thread ID in the thread_id position" >&2
    exit 1
  fi
  if [[ $# -eq 4 && "$4" == "--body-file" ]]; then
    echo "reply --body-file requires a path" >&2
    exit 1
  fi
  if [[ $# -eq 5 ]]; then
    [[ "$4" == "--body-file" ]] || usage
    [[ -f "$5" ]] || { echo "body file not found: $5" >&2; exit 1; }
    [[ -s "$5" ]] || { echo "body file is empty: $5" >&2; exit 1; }
  fi
fi

if [[ "$cmd" == "reopen" ]]; then
  [ $# -eq 2 ] || usage
  [[ "$2" == PRRT_* ]] || {
    echo "reopen expects a review thread ID as its second argument" >&2
    exit 1
  }
fi

read -r OWNER REPO < <(gh repo view --json owner,name --jq '"\(.owner.login) \(.name)"')

case "$cmd" in
  list)
    [ $# -eq 1 ] || usage
    PR=$1
    gh api graphql -f query='
      query($owner: String!, $repo: String!, $pr: Int!) {
        repository(owner: $owner, name: $repo) {
          pullRequest(number: $pr) {
            reviewThreads(first: 100) {
              nodes {
                id
                isResolved
                path
                comments(first: 1) {
                  nodes { databaseId author { login } body }
                }
              }
            }
          }
        }
      }' -f owner="$OWNER" -f repo="$REPO" -F pr="$PR" \
    | jq -r '.data.repository.pullRequest.reviewThreads.nodes
             | map(select(.isResolved == false))
             | .[]
             | "\(.id)\t\(.comments.nodes[0].databaseId)\t\(.comments.nodes[0].author.login)\t\(.path)\t\(.comments.nodes[0].body | gsub("\n"; " ") | .[0:120])"'
    ;;

  show)
    [ $# -eq 2 ] || usage
    PR=$1; TARGET=$2
    case "$TARGET" in
      PRRT_*)
        gh api graphql -f query='
          query($id: ID!) {
            node(id: $id) {
              ... on PullRequestReviewThread {
                id
                isResolved
                path
                line
                pullRequest { number }
                comments(first: 100) {
                  nodes {
                    databaseId
                    author { login }
                    body
                    path
                    line
                    commit { oid }
                    url
                    createdAt
                  }
                }
              }
            }
          }' -f id="$TARGET" \
        | jq -r --argjson pr "$PR" '
            .data.node as $thread
            | if $thread == null then error("thread not found")
              elif $thread.pullRequest.number != $pr then error("thread belongs to PR #\($thread.pullRequest.number), not #\($pr)")
              else
                "thread_id: \($thread.id)",
                "resolved: \($thread.isResolved)",
                "path: \($thread.path // "-")",
                "line: \($thread.line // "-")",
                "comments:",
                ($thread.comments.nodes[] | [
                  "  comment_id: \(.databaseId)",
                  "  author: \(.author.login // "-")",
                  "  path: \(.path // $thread.path // "-")",
                  "  line: \(.line // "-")",
                  "  commit_id: \(.commit.oid // "-")",
                  "  html_url: \(.url // "-")",
                  "  created_at: \(.createdAt // "-")",
                  "  body:",
                  (.body | split("\n") | map("    " + .) | join("\n"))
                ] | join("\n"))
              end'
        ;;
      *)
        gh api "repos/$OWNER/$REPO/pulls/comments/$TARGET" \
        | jq -r --argjson pr "$PR" '
            (.pull_request_url | capture("/pulls/(?<number>[0-9]+)$").number | tonumber) as $comment_pr
            | if $comment_pr != $pr then error("comment belongs to PR #\($comment_pr), not #\($pr)")
              else
                "comment_id: \(.id)",
                "author: \(.user.login // "-")",
                "path: \(.path // "-")",
                "line: \(.line // "-")",
                "commit_id: \(.commit_id // "-")",
                "html_url: \(.html_url // "-")",
                "created_at: \(.created_at // "-")",
                "body:",
                (.body | split("\n") | map("  " + .) | join("\n"))
              end'
        ;;
    esac
    ;;

  reopen)
    PR=$1; THREAD_ID=$2
    if ! THREAD_JSON=$(gh api graphql -f query='
      query($id: ID!) {
        node(id: $id) {
          ... on PullRequestReviewThread {
            id
            isResolved
            pullRequest { number repository { nameWithOwner } }
          }
        }
      }' -f id="$THREAD_ID"); then
      echo "failed to fetch review thread $THREAD_ID for PR #$PR" >&2
      exit 1
    fi
    if ! jq -e --arg pr "$PR" --arg thread_id "$THREAD_ID" --arg repository "$OWNER/$REPO" '
      .data.node as $thread
      | if $thread == null then error("review thread \($thread_id) not found on PR #\($pr)")
        elif (($thread.pullRequest.number // -1) | tostring) != $pr then
          error("thread belongs to PR #\($thread.pullRequest.number), not #\($pr)")
        elif (($thread.pullRequest.repository.nameWithOwner // "") != $repository) then
          ($thread.pullRequest.repository.nameWithOwner // "unknown") as $thread_repository
          | error("thread belongs to repository \($thread_repository), not \($repository)")
        elif $thread.isResolved != true then error("thread is not resolved")
        else true
        end' <<<"$THREAD_JSON" >/dev/null; then
      exit 1
    fi
    if ! UNRESOLVE_JSON=$(gh api graphql -f query='mutation($t: ID!) { unresolveReviewThread(input: {threadId: $t}) { thread { isResolved } } }' \
      -f t="$THREAD_ID"); then
      echo "failed to reopen review thread $THREAD_ID on PR #$PR" >&2
      exit 1
    fi
    if ! jq -e '.data.unresolveReviewThread.thread.isResolved == false' <<<"$UNRESOLVE_JSON" >/dev/null; then
      echo "GitHub returned an invalid reopen response for review thread $THREAD_ID on PR #$PR" >&2
      exit 1
    fi
    echo "ok $THREAD_ID"
    ;;

  reply)
    [[ $# -eq 4 || $# -eq 5 ]] || usage
    PR=$1; COMMENT_ID=$2; THREAD_ID=$3
    if [[ $# -eq 5 ]]; then
      BODY=$(<"$5")
    else
      BODY=$4
    fi
    gh api -X POST "repos/$OWNER/$REPO/pulls/$PR/comments/$COMMENT_ID/replies" \
      -f body="$BODY" --silent
    gh api graphql -f query='mutation($t: ID!) { resolveReviewThread(input: {threadId: $t}) { thread { isResolved } } }' \
      -f t="$THREAD_ID" --silent
    gh api -X POST "repos/$OWNER/$REPO/pulls/comments/$COMMENT_ID/reactions" \
      -f content="+1" --silent
    echo "ok $THREAD_ID"
    ;;

  *)
    usage
    ;;
esac