#!/usr/bin/env bash
# Regression harness for pr-merge.sh identity-first principal resolution
# (mosaicstack/stack #1280).
#
# Covers:
#   1. --dry-run reports the acting principal the merge WOULD use, resolved the
#      same way the real merge resolves it: --login > MOSAIC_GIT_IDENTITY /
#      git config mosaic.gitIdentity > shared host credential. (The pre-#1280
#      deployed copy reported a tea login that the merge would not act as.)
#   2. --dry-run fails closed when the requested principal has no credential:
#      unknown --login, or an identity with no per-slot token (stderr names
#      the login / the identity and its slot path).
#   3. The real merge POST carries the resolved principal's credential and no
#      other: --login merges with that login's tea-config token; an identity
#      merges with the per-slot token; an unresolvable --login never reaches
#      the provider.
#
# Fixture pattern from test-pr-merge-head-pin.sh: the scripts under test are
# copied into a fixture tree with stubbed pr-metadata.sh / ci-queue-wait.sh
# siblings; the provider is a stubbed curl that records the credential it
# received. NEVER reads real secrets or hits a live forge.

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
WORK_DIR="${MOSAIC_TEST_WORK_DIR:-$PWD/.mosaic-test-work/pr-merge-principal-resolution}"
FAKE_HOME="$WORK_DIR/home"
REPO_DIR="$WORK_DIR/repo"
TOOLS_DIR="$WORK_DIR/tools"
BIN_DIR="$WORK_DIR/bin"
LOG_FILE="$WORK_DIR/calls.log"
CREDENTIALS_FILE="$FAKE_HOME/.config/mosaic/credentials.json"
SHA=0123456789abcdef0123456789abcdef01234567

rm -rf "$WORK_DIR"
mkdir -p "$FAKE_HOME/.config/mosaic/secrets/gitea-tokens" "$FAKE_HOME/.config/tea" \
  "$REPO_DIR" "$TOOLS_DIR/git" "$TOOLS_DIR/_lib" "$BIN_DIR"

cp "$SCRIPT_DIR/pr-merge.sh" "$TOOLS_DIR/git/pr-merge.sh"
cp "$SCRIPT_DIR/detect-platform.sh" "$TOOLS_DIR/git/detect-platform.sh"
cp "$SCRIPT_DIR/../_lib/credentials.sh" "$TOOLS_DIR/_lib/credentials.sh"
chmod +x "$TOOLS_DIR/git/pr-merge.sh"

git -C "$REPO_DIR" init -q
git -C "$REPO_DIR" remote add origin https://git.mosaicstack.dev/mosaicstack/stack.git

# Stubbed siblings pr-merge.sh resolves relative to its own SCRIPT_DIR.
cat > "$TOOLS_DIR/git/pr-metadata.sh" <<SH
#!/usr/bin/env bash
printf '%s\n' '{"baseRefName":"next","headRefName":"fix/pinned","headRefOid":"$SHA","headRepository":"mosaicstack/stack","title":"Test PR","author":{"login":"contributor"}}'
SH
cat > "$TOOLS_DIR/git/ci-queue-wait.sh" <<'SH'
#!/usr/bin/env bash
exit 0
SH
chmod +x "$TOOLS_DIR/git/pr-metadata.sh" "$TOOLS_DIR/git/ci-queue-wait.sh"

cat > "$CREDENTIALS_FILE" <<'JSON'
{
  "gitea": {
    "mosaicstack": {
      "url": "https://git.mosaicstack.dev",
      "token": "shared-mosaicstack-token"
    }
  }
}
JSON

cat > "$FAKE_HOME/.config/tea/config.yml" <<'YAML'
logins:
- name: fred-ms
  url: https://git.mosaicstack.dev
  token: SECRET-fred-ms-tea-token
YAML

echo -n "SECRET-agentX-slot-token" > "$FAKE_HOME/.config/mosaic/secrets/gitea-tokens/gitea-mosaicstack-agentX.token"

: > "$LOG_FILE"

# Stubbed tea for login-list resolution only.
cat > "$BIN_DIR/tea" <<'SH'
#!/usr/bin/env bash
set -euo pipefail
if [[ "$*" == "login list --output json" ]]; then
    cat <<'JSON'
[
  {"name":"fred-ms","url":"https://git.mosaicstack.dev","default":true}
]
JSON
    exit 0
fi
exit 0
SH
chmod +x "$BIN_DIR/tea"

# Stubbed provider. pr-merge passes curl config on STDIN with -K -; the stub
# reads stdin, records the Authorization header it received, answers 200.
cat > "$BIN_DIR/curl" <<SH
#!/usr/bin/env bash
set -euo pipefail
url=""
out_file=""
stdin_config=""
if [[ ! -t 0 ]]; then
    stdin_config="\$(cat || true)"
fi
while [[ \$# -gt 0 ]]; do
    case "\$1" in
        -o) out_file="\$2"; shift 2 ;;
        -K|-w|--max-filesize|--max-time|--connect-timeout|-sS) shift 2 ;;
        *)  [[ -n "\$1" && "\$1" != -* && -z "\$url" ]] && url="\$1"
            shift
            ;;
    esac
done
auth="\$(printf '%s' "\$stdin_config" | grep -o 'Authorization: token [^"]*' || true)"
printf 'CURL-URL: %s\nCURL-AUTH: %s\n' "\$url" "\$auth" >> "$LOG_FILE"
[[ -n "\$out_file" ]] && printf '{}' > "\$out_file"
printf '200\n'
exit 0
SH
chmod +x "$BIN_DIR/curl"

fail=0
assert_contains_log() {
  local desc="$1" needle="$2"
  if ! grep -qF -- "$needle" "$LOG_FILE"; then
    echo "FAIL: $desc — log does not contain '$needle':" >&2
    cat "$LOG_FILE" >&2
    fail=1
  fi
}
assert_not_contains_log() {
  local desc="$1" needle="$2"
  if grep -qF -- "$needle" "$LOG_FILE"; then
    echo "FAIL: $desc — log must not contain '$needle':" >&2
    cat "$LOG_FILE" >&2
    fail=1
  fi
}

run_pr_merge() {
  local extra_args="$1"; shift
  (
    cd "$REPO_DIR"
    # shellcheck disable=SC2086 # extra_args is deliberately word-split wrapper args
    env -i HOME="$FAKE_HOME" PATH="$BIN_DIR:$PATH" \
      GIT_CONFIG_GLOBAL=/dev/null GIT_CONFIG_SYSTEM=/dev/null \
      MOSAIC_CREDENTIALS_FILE="$CREDENTIALS_FILE" "$@" \
      bash "$TOOLS_DIR/git/pr-merge.sh" -n 42 $extra_args
  )
}

# ---------------------------------------------------------------------------
# 1. --dry-run reports the resolved acting principal truthfully.
# ---------------------------------------------------------------------------
out=$(run_pr_merge "--dry-run" MOSAIC_GIT_IDENTITY=agentX)
if [[ "$out" != *"as git identity 'agentX' (per-slot credential)"* ]]; then
  echo "FAIL: dry-run identity — principal not reported: $out" >&2
  fail=1
fi

out=$(run_pr_merge "--dry-run --login fred-ms" MOSAIC_GIT_IDENTITY=agentX)
if [[ "$out" != *"as tea login 'fred-ms'"* ]]; then
  echo "FAIL: dry-run login override — login not reported (must beat env identity): $out" >&2
  fail=1
fi

out=$(run_pr_merge "--dry-run")
if [[ "$out" != *"as default host credential"* ]]; then
  echo "FAIL: dry-run default — not reported: $out" >&2
  fail=1
fi

# ---------------------------------------------------------------------------
# 2. --dry-run fails closed when the requested principal has no credential.
# ---------------------------------------------------------------------------
stderr_file="$WORK_DIR/stderr.tmp"
set +e
out=$(run_pr_merge "--dry-run --login ghost" 2>"$stderr_file")
rc=$?
set -e
if [[ "$rc" -eq 0 ]] || [[ "$(cat "$stderr_file")" != *"ghost"* ]]; then
  echo "FAIL: dry-run unknown --login — expected fail-loud naming 'ghost', rc=$rc" >&2
  cat "$stderr_file" >&2
  fail=1
fi

: > "$stderr_file"
set +e
out=$(run_pr_merge "--dry-run" MOSAIC_GIT_IDENTITY=agentNoSlot 2>"$stderr_file")
rc=$?
set -e
err=$(cat "$stderr_file")
if [[ "$rc" -eq 0 ]] || [[ "$err" != *"agentNoSlot"* ]] \
  || [[ "$err" != *"$FAKE_HOME/.config/mosaic/secrets/gitea-tokens/gitea-mosaicstack-agentNoSlot.token"* ]]; then
  echo "FAIL: dry-run identity without slot — expected fail-loud naming identity + slot path, rc=$rc" >&2
  echo "$err" >&2
  fail=1
fi

# ---------------------------------------------------------------------------
# 3. The real merge POST carries the resolved principal's credential ONLY.
# ---------------------------------------------------------------------------
: > "$LOG_FILE"
set +e
out=$(run_pr_merge "--login fred-ms" MOSAIC_GIT_IDENTITY=agentX 2>"$stderr_file")
rc=$?
set -e
if [[ "$rc" -ne 0 ]]; then
  echo "FAIL: merge with --login — expected rc=0, got $rc" >&2
  cat "$stderr_file" >&2
  fail=1
fi
assert_contains_log "merge --login uses the login token" "CURL-AUTH: Authorization: token SECRET-fred-ms-tea-token"
assert_not_contains_log "merge --login must not use the identity slot token" "SECRET-agentX-slot-token"
assert_not_contains_log "merge --login must not use the shared token" "shared-mosaicstack-token"

: > "$LOG_FILE"
set +e
out=$(run_pr_merge "" MOSAIC_GIT_IDENTITY=agentX 2>"$stderr_file")
rc=$?
set -e
if [[ "$rc" -ne 0 ]]; then
  echo "FAIL: merge with identity — expected rc=0, got $rc" >&2
  cat "$stderr_file" >&2
  fail=1
fi
assert_contains_log "merge identity uses the per-slot token" "CURL-AUTH: Authorization: token SECRET-agentX-slot-token"
assert_not_contains_log "merge identity must not use the shared token" "shared-mosaicstack-token"

: > "$LOG_FILE"
set +e
out=$(run_pr_merge "--login ghost" 2>"$stderr_file")
rc=$?
set -e
if [[ "$rc" -eq 0 ]]; then
  echo "FAIL: merge with unknown --login — expected nonzero, got 0" >&2
  fail=1
fi
assert_not_contains_log "merge with unknown --login must not reach the provider" "CURL-URL"

if [[ "$fail" -eq 0 ]]; then
  echo "pr-merge identity-first principal resolution regression passed"
fi

exit "$fail"