#!/usr/bin/env bash

set -euo pipefail

SCRIPT_DIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
KNOE_HOME=$(cd "$SCRIPT_DIR/../.." && pwd)
SCRIPT_UNDER_TEST="$KNOE_HOME/tools/k3s-cluster-rename.sh"

TMP_DIR=$(mktemp -d)
trap 'rm -rf "$TMP_DIR"' EXIT
export TMP_DIR

BIN_DIR="$TMP_DIR/bin"
mkdir -p "$BIN_DIR"

cat <<'K_EOF' >"$BIN_DIR/kubectl"
#!/usr/bin/env bash
set -euo pipefail

cfg="${KUBECONFIG:?KUBECONFIG is required}"

if [[ "$*" == "config view --raw -o json" ]]; then
  cat "$cfg"
  exit 0
fi

if [[ "$*" == "config get-contexts -o name" ]]; then
  python3 - "$cfg" <<'PY'
import json
import sys

with open(sys.argv[1], "r", encoding="utf-8") as fh:
    data = json.load(fh)

for ctx in data.get("contexts", []):
    name = ctx.get("name") if isinstance(ctx, dict) else None
    if name:
        print(name)
PY
  exit 0
fi

echo "unsupported kubectl invocation: $*" >&2
exit 2
K_EOF
chmod +x "$BIN_DIR/kubectl"

cat <<'X_EOF' >"$BIN_DIR/kubectx"
#!/usr/bin/env bash
set -euo pipefail
echo "$*" >>"${TMP_DIR}/kubectx_calls.log"
exit 0
X_EOF
chmod +x "$BIN_DIR/kubectx"

assert_target_names() {
  local cfg="$1"
  python3 - "$cfg" <<'PY'
import json
import sys

target = "knoe.dev.knoe.org"

with open(sys.argv[1], "r", encoding="utf-8") as fh:
    data = json.load(fh)

context_names = [c.get("name") for c in data.get("contexts", []) if isinstance(c, dict)]
cluster_names = [c.get("name") for c in data.get("clusters", []) if isinstance(c, dict)]
user_names = [u.get("name") for u in data.get("users", []) if isinstance(u, dict)]

assert target in context_names, f"missing target context: {context_names}"
assert target in cluster_names, f"missing target cluster: {cluster_names}"
assert target in user_names, f"missing target user: {user_names}"
assert data.get("current-context") == target, f"unexpected current-context: {data.get('current-context')}"

for ctx in data.get("contexts", []):
    if isinstance(ctx, dict) and ctx.get("name") == target:
        body = ctx.get("context") or {}
        assert body.get("cluster") == target, f"target context cluster mismatch: {body}"
        assert body.get("user") == target, f"target context user mismatch: {body}"
        break
else:
    raise AssertionError("target context body not found")
PY
}

assert_has_kubectx_call() {
  if ! [[ -f "$TMP_DIR/kubectx_calls.log" ]]; then
    echo "FAILURE: expected kubectx to be called" >&2
    exit 1
  fi
  if ! grep -q '^knoe.dev.knoe.org$' "$TMP_DIR/kubectx_calls.log"; then
    echo "FAILURE: expected kubectx to be called with knoe.dev.knoe.org" >&2
    cat "$TMP_DIR/kubectx_calls.log" >&2
    exit 1
  fi
}

create_single_context_cfg() {
  local cfg="$1"
  local name="$2"
  cat >"$cfg" <<EOF
{
  "apiVersion": "v1",
  "kind": "Config",
  "clusters": [
    {
      "name": "${name}",
      "cluster": {
        "server": "https://example:6443",
        "insecure-skip-tls-verify": true
      }
    }
  ],
  "users": [
    {
      "name": "${name}",
      "user": {
        "token": "test-token"
      }
    }
  ],
  "contexts": [
    {
      "name": "${name}",
      "context": {
        "cluster": "${name}",
        "user": "${name}",
        "namespace": "default"
      }
    }
  ],
  "current-context": "${name}"
}
EOF
}

export PATH="$BIN_DIR:$PATH"

# Core rename + idempotency
cfg_primary="$TMP_DIR/kubeconfig-primary.json"
create_single_context_cfg "$cfg_primary" "knoe-k3s"

bash "$SCRIPT_UNDER_TEST" --kubeconfig "$cfg_primary" --no-backup
assert_target_names "$cfg_primary"

bash "$SCRIPT_UNDER_TEST" --kubeconfig "$cfg_primary" --no-backup
assert_target_names "$cfg_primary"
assert_has_kubectx_call

# Repair fallback when old name is absent but only one context exists
cfg_repair="$TMP_DIR/kubeconfig-repair.json"
create_single_context_cfg "$cfg_repair" "default"

bash "$SCRIPT_UNDER_TEST" --kubeconfig "$cfg_repair" --no-backup
assert_target_names "$cfg_repair"

# Default path behavior: active shell kubeconfig (~/.kube/config when KUBECONFIG unset)
home_dir="$TMP_DIR/home"
mkdir -p "$home_dir/.kube"
cfg_default="$home_dir/.kube/config"
create_single_context_cfg "$cfg_default" "knoe-k3s"

unset KUBECONFIG || true
HOME="$home_dir" bash "$SCRIPT_UNDER_TEST" --no-backup
assert_target_names "$cfg_default"

# Negative path: ambiguous fallback must fail
cfg_ambiguous="$TMP_DIR/kubeconfig-ambiguous.json"
cat >"$cfg_ambiguous" <<'EOF'
{
  "apiVersion": "v1",
  "kind": "Config",
  "clusters": [
    {"name": "default", "cluster": {"server": "https://default:6443", "insecure-skip-tls-verify": true}},
    {"name": "other", "cluster": {"server": "https://other:6443", "insecure-skip-tls-verify": true}}
  ],
  "users": [
    {"name": "default", "user": {"token": "t1"}},
    {"name": "other", "user": {"token": "t2"}}
  ],
  "contexts": [
    {"name": "default", "context": {"cluster": "default", "user": "default"}},
    {"name": "other", "context": {"cluster": "other", "user": "other"}}
  ],
  "current-context": "default"
}
EOF

if bash "$SCRIPT_UNDER_TEST" --kubeconfig "$cfg_ambiguous" --no-backup >/dev/null 2>&1; then
  echo "FAILURE: expected ambiguous rename to fail" >&2
  exit 1
fi

echo "SUCCESS"