#!/usr/bin/env bash
# lib/forge-github.sh — the GitHub backend (issue #188, term 1). Sourced by
# lib/forge.sh when forge_detect says github; never at the same time as the
# forgejo backend — they define the same verbs on purpose.
#
# This file is the CURRENT call set, extracted 1:1 and nothing more. Term 5
# of the frozen Spec is "GitHub consumers are unchanged", and the cheapest
# way to keep that true is for every verb here to be a thin pass-through to
# the `gh` invocation the call site used before the port. No behaviour is
# added, fixed or tidied on this path; anything that looks like an
# improvement here is a regression risk against a forge nobody is currently
# reporting bugs on.

# forge_api [--paginate] <endpoint> [--jq <expr>]
#
# The one deliberate difference from a pure pass-through: the caller no
# longer names a page size, because the page-size parameter is not portable
# and is therefore the backend's to own (#188).
#
#   ?per_page=100   GitHub: 100 items      Forgejo: 30 items  (IGNORED)
#   ?limit=100      GitHub:  30 items      Forgejo: 50 items  (capped)
#
# Both answer HTTP 200 either way, so a call site that names one is a silent
# truncation waiting for the other forge. per_page=100 is injected here —
# exactly what the call sites said before — so the GitHub path is unchanged
# in behaviour while the parameter stops being a call-site concern.
forge_api() {
  local paginate=false endpoint="" jqexpr="" have_jq=false
  while [ $# -gt 0 ]; do
    case "$1" in
      --paginate) paginate=true ;;
      --jq) jqexpr="$2"; have_jq=true; shift ;;
      -*) ;;
      *) [ -n "$endpoint" ] || endpoint="$1" ;;
    esac
    shift
  done
  [ -n "$endpoint" ] || { echo "forge_api: endpoint required" >&2; return 1; }

  if [ "$paginate" = true ]; then
    endpoint="$(github_page_url "$endpoint")"
    if [ "$have_jq" = true ]; then
      gh api --paginate "$endpoint" --jq "$jqexpr"
    else
      gh api --paginate "$endpoint"
    fi
  else
    if [ "$have_jq" = true ]; then
      gh api "$endpoint" --jq "$jqexpr"
    else
      gh api "$endpoint"
    fi
  fi
}

# github_page_url <endpoint> — pure, so the page-size contract is testable
# without a network. Strips any page-size parameter a caller left behind in
# either dialect, then applies GitHub's own.
github_page_url() {
  local endpoint="${1:?github_page_url: endpoint required}" clean
  clean="$(printf '%s' "$endpoint" | sed -E 's/([?&])(per_page|limit|page)=[0-9]+/\1/g; s/[?&]+$//; s/([?&])&+/\1/g')"
  case "$clean" in
    *\?) printf '%sper_page=100\n' "$clean" ;;
    *\?*) printf '%s&per_page=100\n' "$clean" ;;
    *) printf '%s?per_page=100\n' "$clean" ;;
  esac
}