#!/usr/bin/env bash
# Resolve the production release SHA shared by the four production workflows.
#
# Validate mode (default): REQUESTED_SHA must be a successful staging push of
# backend-quality-gate, main and staging must be the same head H, and
# is-docs-only-range.sh REQUESTED_SHA H must exit 0.
# Discover mode (RESOLVE_MODE=discover): R is the newest such push whose range
# to H is docs-only.
# CHECK_RELEASE_GATE=true also requires a successful release-quality-gate
# dispatch whose head is R or H.
#
# stdout is three KEY=VALUE lines: release_sha, gate_run_id, head_sha.
# Exit 0 accepted, 1 refused, 2 when the Gitea API cannot be read.
# Tests set JYOTISHA_HTTP_FIXTURE_DIR and JYOTISHA_DOCS_ONLY_MODE=git.
set -euo pipefail

script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd -P)"
python="${JYOTISHA_PYTHON:-python3}"
mode="${RESOLVE_MODE:-validate}"
api_url="${GITEA_API_URL:-https://git.copse.top/api/v1}"
repository="${GITEA_REPOSITORY:-root/Jyotisha}"
docs_mode="${JYOTISHA_DOCS_ONLY_MODE:-api}"

if [[ "$mode" != validate && "$mode" != discover ]]; then
  echo "RESOLVE_MODE must be validate or discover" >&2
  exit 2
fi

http_get() {
  local url="$1" dest="$2"
  if [ -n "${JYOTISHA_HTTP_FIXTURE_DIR:-}" ]; then
    if ! URL="$url" DEST="$dest" FIXTURE_DIR="$JYOTISHA_HTTP_FIXTURE_DIR" "$python" - <<'PY'
import json, os, sys
from pathlib import Path
url = os.environ["URL"]
root = Path(os.environ["FIXTURE_DIR"])
manifest = json.loads((root / "manifest.json").read_text(encoding="utf-8"))
for item in manifest:
    if item["match"] in url:
        status = int(item.get("status", 200))
        if status != 200:
            sys.stderr.write("fixture refused the Gitea request\n")
            sys.exit(1)
        Path(os.environ["DEST"]).write_bytes((root / item["file"]).read_bytes())
        sys.exit(0)
sys.stderr.write("no fixture matched the Gitea request\n")
sys.exit(1)
PY
    then
      return 1
    fi
    return 0
  fi
  local -a auth=()
  if [ -n "${GITEA_TOKEN:-}" ]; then
    auth=(--header "Authorization: token ${GITEA_TOKEN}")
  fi
  if ! curl --fail --silent --show-error --connect-timeout 15 --max-time 60 --retry 3 --retry-all-errors \
    "${auth[@]}" "$url" --output "$dest"; then
    return 1
  fi
}

fetch_json() {
  local url="$1" dest
  dest="$(mktemp)"
  if ! http_get "$url" "$dest"; then
    rm -f -- "$dest"
    echo "Gitea API request failed" >&2
    exit 2
  fi
  printf '%s' "$dest"
}

read_ref_sha() {
  local branch="$1" dest sha
  dest="$(fetch_json "$api_url/repos/$repository/git/refs/heads/$branch")"
  if ! sha="$("$python" - "$branch" "$dest" <<'PY'
import json, re, sys
branch, path = sys.argv[1], sys.argv[2]
try:
    payload = json.loads(open(path, encoding="utf-8").read())
except (OSError, json.JSONDecodeError):
    sys.exit(2)
ref = "refs/heads/" + branch
if not isinstance(payload, list) or len(payload) != 1 or payload[0].get("ref") != ref:
    sys.exit(2)
sha = ((payload[0].get("object") or {}).get("sha") or "")
if not re.fullmatch(r"[0-9a-f]{40}", sha):
    sys.exit(2)
print(sha)
PY
  )"; then
    rm -f -- "$dest"
    echo "Gitea ref for $branch is unreadable" >&2
    exit 2
  fi
  rm -f -- "$dest"
  printf '%s' "$sha"
}

gate_id_for() {
  local sha="$1" dest gate_id
  dest="$(fetch_json "$api_url/repos/$repository/actions/runs?head_sha=$sha&branch=staging&event=push&status=success&limit=100")"
  set +e
  gate_id="$("$python" - "$sha" "$dest" <<'PY'
import json, sys
sha, path = sys.argv[1], sys.argv[2]
try:
    payload = json.loads(open(path, encoding="utf-8").read())
except (OSError, json.JSONDecodeError):
    sys.exit(2)
runs = payload.get("workflow_runs") or []
matched = []
for run in runs:
    workflow = str(run.get("path") or "").split("@", 1)[0]
    if (
        workflow.endswith("backend-quality-gate.yml")
        and run.get("head_sha") == sha
        and run.get("head_branch") == "staging"
        and run.get("event") == "push"
        and run.get("conclusion") == "success"
    ):
        matched.append(run)
if not matched:
    sys.exit(1)
matched.sort(key=lambda run: int(run.get("id") or 0), reverse=True)
print(int(matched[0]["id"]))
PY
  )"
  local status=$?
  set -e
  rm -f -- "$dest"
  if [ "$status" -eq 2 ]; then
    echo "Gitea gate run list is unreadable" >&2
    exit 2
  fi
  if [ "$status" -ne 0 ]; then
    echo "no successful exact-SHA production quality gate run found" >&2
    exit 1
  fi
  printf '%s' "$gate_id"
}

require_docs_only() {
  local base="$1" head="$2" status
  set +e
  bash "$script_dir/is-docs-only-range.sh" "--$docs_mode" "$base" "$head" >&2
  status=$?
  set -e
  if [ "$status" -ne 0 ]; then
    echo "release SHA is not a docs-only ancestor of the staging head" >&2
    exit 1
  fi
}

require_release_gate() {
  local release="$1" head="$2" sha dest status found=false
  for sha in "$release" "$head"; do
    dest="$(fetch_json "$api_url/repos/$repository/actions/runs?head_sha=$sha&event=workflow_dispatch&status=success&limit=100")"
    set +e
    "$python" - "$sha" "$dest" <<'PY'
import json, sys
sha, path = sys.argv[1], sys.argv[2]
try:
    payload = json.loads(open(path, encoding="utf-8").read())
except (OSError, json.JSONDecodeError):
    sys.exit(2)
runs = payload.get("workflow_runs") or []
for run in runs:
    workflow = str(run.get("path") or "").split("@", 1)[0]
    if (
        workflow.endswith("release-quality-gate.yml")
        and run.get("head_sha") == sha
        and run.get("event") == "workflow_dispatch"
        and run.get("conclusion") == "success"
    ):
        sys.exit(0)
sys.exit(1)
PY
    status=$?
    set -e
    rm -f -- "$dest"
    if [ "$status" -eq 0 ]; then
      found=true
      break
    fi
    if [ "$status" -eq 2 ]; then
      echo "Gitea release gate list is unreadable" >&2
      exit 2
    fi
  done
  if [ "$found" != true ]; then
    echo "no successful manual release quality gate found for the release SHA or current main" >&2
    exit 1
  fi
}

staging_head="$(read_ref_sha staging)"
main_head="$(read_ref_sha main)"
if [ "$main_head" != "$staging_head" ]; then
  echo "main and staging must identify the same reviewed release" >&2
  exit 1
fi
head_sha="$staging_head"

if [ "$mode" = validate ]; then
  [[ "${REQUESTED_SHA:-}" =~ ^[0-9a-f]{40}$ ]] || {
    echo "deploy_sha must be a lowercase full commit SHA" >&2
    exit 1
  }
  release_sha="$REQUESTED_SHA"
  gate_run_id="$(gate_id_for "$release_sha")"
  require_docs_only "$release_sha" "$head_sha"
else
  list="$(fetch_json "$api_url/repos/$repository/actions/runs?branch=staging&event=push&status=success&limit=100")"
  set +e
  candidates="$("$python" - "$list" <<'PY'
import json, sys
try:
    payload = json.loads(open(sys.argv[1], encoding="utf-8").read())
except (OSError, json.JSONDecodeError):
    sys.exit(2)
best = {}
for run in payload.get("workflow_runs") or []:
    workflow = str(run.get("path") or "").split("@", 1)[0]
    sha = run.get("head_sha") or ""
    if (
        workflow.endswith("backend-quality-gate.yml")
        and run.get("head_branch") == "staging"
        and run.get("event") == "push"
        and run.get("conclusion") == "success"
        and len(sha) == 40
    ):
        run_id = int(run.get("id") or 0)
        if sha not in best or run_id > best[sha]:
            best[sha] = run_id
for sha, run_id in sorted(best.items(), key=lambda item: item[1], reverse=True):
    print(f"{sha} {run_id}")
PY
  )"
  status=$?
  set -e
  rm -f -- "$list"
  if [ "$status" -eq 2 ]; then
    echo "Gitea gate run list is unreadable" >&2
    exit 2
  fi
  release_sha=""
  gate_run_id=""
  while read -r candidate_sha candidate_id; do
    [ -n "$candidate_sha" ] || continue
    set +e
    bash "$script_dir/is-docs-only-range.sh" "--$docs_mode" "$candidate_sha" "$head_sha" >&2
    status=$?
    set -e
    if [ "$status" -eq 0 ]; then
      release_sha="$candidate_sha"
      gate_run_id="$candidate_id"
      break
    fi
  done <<<"$candidates"
  if [ -z "$release_sha" ]; then
    echo "no docs-only staging quality gate can be released" >&2
    exit 1
  fi
fi

if [ "${CHECK_RELEASE_GATE:-}" = true ]; then
  require_release_gate "$release_sha" "$head_sha"
fi

printf 'release_sha=%s\n' "$release_sha"
printf 'gate_run_id=%s\n' "$gate_run_id"
printf 'head_sha=%s\n' "$head_sha"