#!/usr/bin/env bash
# Regression harness for detect-platform.sh's resolve_gitea_principal() — the
# identity-first acting-principal resolution shared by the git wrappers
# (mosaicstack/stack #1280).
#
# The contract under test (precedence: --login > MOSAIC_GIT_IDENTITY /
# git config mosaic.gitIdentity > tea login list, which is the LAST resort):
#   1. identity env + per-slot token present -> mode=identity, principal=
#      identity name, source names the identity's slot PATH (never a token
#      value).
#   2. identity env + per-slot token ABSENT -> FAIL LOUD: nonzero, empty
#      stdout, stderr naming the identity and the expected slot path.
#   3. identity env + --login -> --login wins (login mode resolves even when
#      the identity has no slot — operator intent beats environment).
#   4. identity unset + no --login -> default mode: the tea login list
#      resolves the principal exactly as before (preserved behavior).
#   5. no identity + no host-matching tea login -> default/host-credential
#      (preserved behavior; absence is not an error on the default path).
#   6. identity on an UNRECOGNIZED host (no per-slot scheme) -> does not bind;
#      default mode (containment, mirroring get_gitea_token).
#   7. --login with no host-bound token for that login -> FAIL LOUD, stderr
#      naming the login and the host.
#   8. git config mosaic.gitIdentity is honored when the env var is unset.
#   9. The resolver NEVER emits a token value — stdout/stderr of every
#      successful resolution must not contain the slot file's contents.
#
# Uses a stubbed tea binary, stubbed tea config.yml, stubbed credentials.json
# and stubbed per-slot token files under a fake HOME. NEVER reads real secrets.

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
WORK_DIR="${MOSAIC_TEST_WORK_DIR:-$PWD/.mosaic-test-work/gitea-principal-resolution}"
FAKE_HOME="$WORK_DIR/home"
REPO_DIR="$WORK_DIR/repo"
BIN_DIR="$WORK_DIR/bin"
CREDENTIALS_FILE="$FAKE_HOME/.config/mosaic/credentials.json"

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

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

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

# tea's own config store: the source get_gitea_token_for_login reads. Logins
# "alice" (mosaicstack) and "bob-usc" (usc) carry sentinel token values that
# the assertions prove are NEVER emitted by the resolver.
cat > "$FAKE_HOME/.config/tea/config.yml" <<'YAML'
logins:
- name: alice
  url: https://git.mosaicstack.dev
  token: SECRET-alice-tea-token
- name: bob-usc
  url: https://git.uscllc.com
  token: SECRET-bob-usc-tea-token
YAML

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

# Per-slot identity token with a sentinel value the assertions prove is never
# emitted (proving "token came from the identity's slot BY PATH, not by value").
echo -n "SECRET-agentX-slot-token" > "$FAKE_HOME/.config/mosaic/secrets/gitea-tokens/gitea-mosaicstack-agentX.token"

fail=0
assert_eq() {
  local desc="$1" expected="$2" actual="$3"
  if [[ "$expected" != "$actual" ]]; then
    echo "FAIL: $desc — expected '$expected', got '$actual'" >&2
    fail=1
  fi
}
assert_contains() {
  local desc="$1" haystack="$2" needle="$3"
  if [[ "$haystack" != *"$needle"* ]]; then
    echo "FAIL: $desc — missing '$needle' in: $haystack" >&2
    fail=1
  fi
}
assert_not_contains() {
  local desc="$1" haystack="$2" needle="$3"
  if [[ "$haystack" == *"$needle"* ]]; then
    echo "FAIL: $desc — must not contain '$needle', got: $haystack" >&2
    fail=1
  fi
}

# Runs resolve_gitea_principal for $1=login_override $2=host inside REPO_DIR
# (per-worktree git config resolves there) under a fake HOME, stubbed tea, and
# stubbed credentials. Extra env (e.g. MOSAIC_GIT_IDENTITY) via $@.
call_resolver() {
  local login="$1" host="$2"; shift 2
  (
    cd "$REPO_DIR"
    env -i HOME="$FAKE_HOME" PATH="$BIN_DIR:$PATH" \
      GIT_CONFIG_GLOBAL=/dev/null GIT_CONFIG_SYSTEM=/dev/null \
      MOSAIC_CREDENTIALS_FILE="$CREDENTIALS_FILE" \
      DETECT_PLATFORM_SH="$SCRIPT_DIR/detect-platform.sh" "$@" \
      bash -c 'source "$DETECT_PLATFORM_SH"; resolve_gitea_principal "$1" "$2"' _ "$login" "$host"
  )
}

field() { printf '%s' "$1" | cut -f"$2"; }

# ---------------------------------------------------------------------------
# 1. Identity env + slot present -> identity mode, slot named BY PATH, and no
#    token value ever emitted.
# ---------------------------------------------------------------------------
git -C "$REPO_DIR" config --unset mosaic.gitIdentity 2>/dev/null || true
out=$(call_resolver "" "git.mosaicstack.dev" MOSAIC_GIT_IDENTITY=agentX)
assert_eq "identity mode"            "identity" "$(field "$out" 1)"
assert_eq "identity principal"       "agentX"   "$(field "$out" 2)"
assert_eq "identity slot source" \
  "identity-slot:$FAKE_HOME/.config/mosaic/secrets/gitea-tokens/gitea-mosaicstack-agentX.token" \
  "$(field "$out" 3)"
assert_not_contains "identity stdout leaks token" "$out" "SECRET"

# ---------------------------------------------------------------------------
# 2. Identity env + slot ABSENT -> fail loud: nonzero, empty stdout, stderr
#    naming the identity and the expected slot path.
# ---------------------------------------------------------------------------
stderr_file="$WORK_DIR/stderr.tmp"
set +e
out=$(call_resolver "" "git.mosaicstack.dev" MOSAIC_GIT_IDENTITY=agentNoSlot 2>"$stderr_file")
rc=$?
set -e
if [[ "$rc" -eq 0 ]]; then
  echo "FAIL: missing slot — expected nonzero return, got 0 (stdout='$out')" >&2
  fail=1
fi
if [[ -n "$out" ]]; then
  echo "FAIL: missing slot — expected empty stdout, got '$out'" >&2
  fail=1
fi
err=$(cat "$stderr_file")
assert_contains "missing slot names identity"  "$err" "agentNoSlot"
assert_contains "missing slot names slot path" "$err" \
  "$FAKE_HOME/.config/mosaic/secrets/gitea-tokens/gitea-mosaicstack-agentNoSlot.token"
assert_not_contains "missing-slot stderr leaks token" "$err" "SECRET"

# ---------------------------------------------------------------------------
# 3. Identity + --login -> --login wins. Also wins when the identity has NO
#    slot (no identity check may veto an explicit login).
# ---------------------------------------------------------------------------
out=$(call_resolver "alice" "git.mosaicstack.dev" MOSAIC_GIT_IDENTITY=agentX)
assert_eq "login beats identity (mode)"      "login" "$(field "$out" 1)"
assert_eq "login beats identity (principal)" "alice" "$(field "$out" 2)"
assert_eq "login source" "tea-login:alice" "$(field "$out" 3)"
out=$(call_resolver "alice" "git.mosaicstack.dev" MOSAIC_GIT_IDENTITY=agentNoSlot)
assert_eq "login beats slot-less identity" "login" "$(field "$out" 1)"

# ---------------------------------------------------------------------------
# 4. No identity, no --login -> default mode via the tea login list
#    (preserved behavior).
# ---------------------------------------------------------------------------
out=$(call_resolver "" "git.mosaicstack.dev")
assert_eq "default mode"          "default" "$(field "$out" 1)"
assert_eq "default principal"     "alice"   "$(field "$out" 2)"
assert_eq "default source"        "tea-default" "$(field "$out" 3)"

# ---------------------------------------------------------------------------
# 5. No identity, no --login, no host-matching tea login -> default with the
#    host credential (absence is not an error on the default path).
# ---------------------------------------------------------------------------
out=$(call_resolver "" "git.unknown.test")
assert_eq "no-match default mode"  "default" "$(field "$out" 1)"
assert_eq "no-match default principal" "" "$(field "$out" 2)"
assert_eq "no-match default source" "host-credential" "$(field "$out" 3)"

# ---------------------------------------------------------------------------
# 6. Identity on an UNRECOGNIZED host -> does not bind; default mode
#    (containment, mirroring get_gitea_token's scope).
# ---------------------------------------------------------------------------
out=$(call_resolver "" "github.com" MOSAIC_GIT_IDENTITY=agentX)
assert_eq "unrecognized host falls to default" "default" "$(field "$out" 1)"

# ---------------------------------------------------------------------------
# 7. --login with no host-bound token for that login -> fail loud, stderr
#    naming the login and the host.
# ---------------------------------------------------------------------------
: > "$stderr_file"
set +e
out=$(call_resolver "ghost-login" "git.mosaicstack.dev" 2>"$stderr_file")
rc=$?
set -e
if [[ "$rc" -eq 0 ]]; then
  echo "FAIL: unknown --login — expected nonzero return, got 0 (stdout='$out')" >&2
  fail=1
fi
err=$(cat "$stderr_file")
assert_contains "unknown login names login" "$err" "ghost-login"
assert_contains "unknown login names host"  "$err" "git.mosaicstack.dev"
# A cross-host login (exists, but for usc) must ALSO fail loud for mosaicstack.
set +e
out=$(call_resolver "bob-usc" "git.mosaicstack.dev" 2>"$stderr_file")
rc=$?
set -e
if [[ "$rc" -eq 0 ]]; then
  echo "FAIL: cross-host --login — expected nonzero return, got 0" >&2
  fail=1
fi

# ---------------------------------------------------------------------------
# 8. git config mosaic.gitIdentity honored when env is unset.
# ---------------------------------------------------------------------------
git -C "$REPO_DIR" config mosaic.gitIdentity agentX
out=$(call_resolver "" "git.mosaicstack.dev")
assert_eq "git-config identity mode" "identity" "$(field "$out" 1)"
assert_eq "git-config identity principal" "agentX" "$(field "$out" 2)"
git -C "$REPO_DIR" config --unset mosaic.gitIdentity

# ---------------------------------------------------------------------------
# 9. Cross-host slot layout: the usc slot path is chosen for the usc host.
# ---------------------------------------------------------------------------
echo -n "SECRET-agentX-usc-token" > "$FAKE_HOME/.config/mosaic/secrets/gitea-tokens/gitea-usc-agentX.token"
out=$(call_resolver "" "git.uscllc.com" MOSAIC_GIT_IDENTITY=agentX)
assert_eq "usc identity mode" "identity" "$(field "$out" 1)"
assert_eq "usc slot source" \
  "identity-slot:$FAKE_HOME/.config/mosaic/secrets/gitea-tokens/gitea-usc-agentX.token" \
  "$(field "$out" 3)"

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

exit "$fail"