pic/api/service_registry.py

"""
ServiceRegistry — single source of truth for all PIC services.

Merges three layers:
  1. Manifest defaults (config_schema.*.default)
  2. Admin-saved config from ConfigManager (cell_config.json)
  3. Runtime state from installed store records

All consumers (CaddyManager, backup, peer services endpoint) read from here
rather than hardcoding service names or subdomains.
"""

import json
import logging
import os
import re
from typing import Dict, List, Optional
from urllib.parse import quote as _urlquote

logger = logging.getLogger('picell')

# Built-ins are baked into the container image at build time.
# Do not bind-mount this path read-write in docker-compose.
_BUILTINS_DIR = os.path.join(os.path.dirname(__file__), 'services', 'builtins')

_SUBDOMAIN_RE = re.compile(r'^[a-z][a-z0-9-]{0,30}$')
_BACKEND_RE   = re.compile(r'^[A-Za-z0-9._-]+:\d{1,5}$')
_RESERVED_SUBS = frozenset({'api', 'webui', 'admin', 'www', 'ns1', 'ns2', 'git', 'registry', 'install'})


class ServiceRegistry:

    def __init__(self, config_manager):
        self._cm = config_manager

    # ── Manifest loading ──────────────────────────────────────────────────

    def _load_manifest(self, path: str) -> Optional[Dict]:
        try:
            with open(path) as f:
                return json.load(f)
        except Exception as e:
            logger.warning('ServiceRegistry: failed to load manifest %s: %s', path, e)
            return None

    def _builtin_ids(self) -> List[str]:
        if not os.path.isdir(_BUILTINS_DIR):
            return []
        return sorted(
            d for d in os.listdir(_BUILTINS_DIR)
            if os.path.isfile(os.path.join(_BUILTINS_DIR, d, 'manifest.json'))
        )

    def _builtin_manifest(self, service_id: str) -> Optional[Dict]:
        return self._load_manifest(
            os.path.join(_BUILTINS_DIR, service_id, 'manifest.json')
        )

    # ── Config merging ────────────────────────────────────────────────────

    _TYPE_COERCIONS = {'integer': int, 'string': str, 'boolean': bool}

    def _merged_config(self, manifest: Dict) -> Dict:
        """Return manifest defaults overridden by admin-saved values, type-coerced."""
        svc_id = manifest.get('id', '')
        saved = self._cm.configs.get(svc_id, {})
        schema = manifest.get('config_schema') or {}
        merged = {k: v['default'] for k, v in schema.items() if 'default' in v}
        for k, spec in schema.items():
            if k not in saved:
                continue
            raw = saved[k]
            coerce = self._TYPE_COERCIONS.get(spec.get('type', ''))
            if coerce is not None:
                try:
                    raw = coerce(raw)
                except (TypeError, ValueError):
                    raw = merged.get(k, raw)
            merged[k] = raw
        return merged

    # ── Public API ────────────────────────────────────────────────────────

    def get(self, service_id: str) -> Optional[Dict]:
        """Return manifest + merged config for one service, or None if unknown."""
        manifest = self._builtin_manifest(service_id)
        if manifest is None:
            record = self._cm.get_installed_services().get(service_id)
            if record:
                manifest = record.get('manifest')
        if not manifest:
            return None
        return {**manifest, 'config': self._merged_config(manifest)}

    def list_all(self) -> List[Dict]:
        """
        Return all services — builtins first, then installed store services —
        each with merged config attached as the 'config' key.
        """
        results: List[Dict] = []
        seen: set = set()

        for svc_id in self._builtin_ids():
            manifest = self._builtin_manifest(svc_id)
            if manifest:
                results.append({**manifest, 'config': self._merged_config(manifest)})
                seen.add(svc_id)

        for svc_id, record in self._cm.get_installed_services().items():
            if svc_id in seen:
                continue
            manifest = record.get('manifest') or {}
            if manifest.get('id'):
                results.append({**manifest, 'config': self._merged_config(manifest)})

        return results

    def get_caddy_routes(self) -> List[Dict]:
        """
        Return routing info for all services that have a subdomain.
        Used by CaddyManager to build service blocks without hardcoding.

        Values are validated here as a chokepoint so Caddyfile/DNS builders
        can safely interpolate them regardless of how manifests reached disk.
        """
        routes = []
        for svc in self.list_all():
            caps = svc.get('capabilities') or {}
            if not caps.get('has_subdomain'):
                continue
            sub = svc.get('subdomain', '')
            bknd = svc.get('backend', '')
            if not sub or not bknd:
                continue
            svc_id = svc.get('id', '?')
            if not _SUBDOMAIN_RE.match(sub) or sub in _RESERVED_SUBS:
                logger.warning('ServiceRegistry: skipping %s — invalid/reserved subdomain %r', svc_id, sub)
                continue
            if not _BACKEND_RE.match(bknd):
                logger.warning('ServiceRegistry: skipping %s — invalid backend %r', svc_id, bknd)
                continue
            extra_subs = [
                s for s in (svc.get('extra_subdomains') or [])
                if isinstance(s, str) and _SUBDOMAIN_RE.match(s) and s not in _RESERVED_SUBS
            ]
            extra_backends = {
                k: v for k, v in (svc.get('extra_backends') or {}).items()
                if (isinstance(k, str) and _SUBDOMAIN_RE.match(k) and k not in _RESERVED_SUBS
                    and isinstance(v, str) and _BACKEND_RE.match(v))
            }
            routes.append({
                'service_id': svc_id,
                'subdomain': sub,
                'backend': bknd,
                'extra_subdomains': extra_subs,
                'extra_backends': extra_backends,
            })
        return routes

    def get_backup_plan(self) -> List[Dict]:
        """
        Return backup declarations for all services that have storage.
        Used by the backup system instead of hardcoded file lists.

        Each entry:
          service_id   — service identifier
          volumes      — list of {container, path, name} for docker-exec streaming
          config_paths — host-relative paths copied directly (config files)
        """
        plan = []
        for svc in self.list_all():
            caps = svc.get('capabilities') or {}
            if not caps.get('has_storage'):
                continue
            backup = svc.get('backup') or {}
            volumes = backup.get('volumes') or []
            config_paths = backup.get('config_paths') or []
            if not volumes and not config_paths:
                continue
            plan.append({
                'service_id': svc['id'],
                'volumes': volumes,
                'config_paths': config_paths,
            })
        return plan

    def get_peer_service_info(self, service_id: str, peer_username: str,
                              domain: str, credentials: Dict) -> Optional[Dict]:
        """
        Fill peer_config_template for one service+peer combination.
        credentials: dict of {field_name: value} for that peer+service.
        Returns None if service unknown or has no peer template.
        """
        svc = self.get(service_id)
        if not svc:
            return None
        template = svc.get('peer_config_template')
        if not template:
            return None

        # URL-safe peer username (safe='') — prevents path traversal in CalDAV/WebDAV URLs
        safe_username = _urlquote(peer_username, safe='')

        result = {}
        for key, raw in template.items():
            val = raw
            val = val.replace('{domain}', domain)
            val = val.replace('{peer.username}', safe_username)
            for field, cred_val in credentials.items():
                val = val.replace(
                    '{peer.service_credentials.' + service_id + '.' + field + '}',
                    str(cred_val) if cred_val is not None else '',
                )
            cfg = svc.get('config') or {}
            for cfg_key, cfg_val in cfg.items():
                val = val.replace('{config.' + cfg_key + '}', str(cfg_val) if cfg_val is not None else '')
            result[key] = val
        return result