"""
Multi-Tenant Configuration Manager (Phase 3B).

Manages tenant-specific configuration overrides including:
  - Enabled wedges and journeys per tenant
  - Custom escalation rules (institution-specific clinical protocols)
  - Domain overrides (enable/disable specific domains)
  - Institution context (nurse line, ED name, timezone, branding)
  - FHIR data source configuration
  - Compliance settings (audit retention, PHI logging)

Usage:
    manager = TenantManager(config)
    tenant = manager.get_tenant("example_health_system")
    merged_rules = manager.get_merged_escalation_rules("example_health_system")
    enabled_domains = manager.get_enabled_domains("example_health_system")
"""

from __future__ import annotations

import logging
from typing import Any, Dict, List, Optional, Set

from decision.engine.config_loader import DecisionConfigLoader

logger = logging.getLogger("decision.tenant_manager")


class TenantConfig:
    """Parsed tenant configuration with convenience accessors."""

    def __init__(self, tenant_id: str, raw: Dict[str, Any]):
        self.tenant_id = tenant_id
        self._raw = raw

    @property
    def name(self) -> str:
        return self._raw.get("institution_name", self.tenant_id)

    @property
    def type(self) -> str:
        return self._raw.get("institution_type", "unknown")

    @property
    def enabled_wedges(self) -> List[str]:
        return self._raw.get("enabled_wedges", [])

    @property
    def enabled_journeys(self) -> List[str]:
        return self._raw.get("enabled_journeys", self.enabled_wedges)

    @property
    def custom_escalation_rules(self) -> List[Dict[str, Any]]:
        return self._raw.get("custom_escalation_rules", [])

    @property
    def domain_overrides(self) -> Dict[str, Any]:
        return self._raw.get("domain_overrides", {})

    @property
    def disabled_domains(self) -> Set[str]:
        overrides = self.domain_overrides
        return {
            domain
            for domain, cfg in overrides.items()
            if isinstance(cfg, dict) and not cfg.get("enabled", True)
        }

    @property
    def institution_context(self) -> Dict[str, Any]:
        return self._raw.get("institution_context", {})

    @property
    def nurse_line_number(self) -> str:
        return self.institution_context.get("nurse_line_number", "")

    @property
    def ed_name(self) -> str:
        return self.institution_context.get("ed_name", "the emergency department")

    @property
    def timezone(self) -> str:
        return self.institution_context.get("timezone", "America/New_York")

    @property
    def operating_hours(self) -> Dict[str, str]:
        return self.institution_context.get("operating_hours", {})

    @property
    def fhir_config(self) -> Dict[str, Any]:
        return self._raw.get("data_source", {}).get("fhir", {})

    @property
    def branding(self) -> Dict[str, str]:
        return self._raw.get("branding", {})

    @property
    def greeting_name(self) -> str:
        return self.branding.get("agent_introduction", "Avery, a care assistant")

    @property
    def compliance(self) -> Dict[str, Any]:
        return self._raw.get("compliance", {})

    @property
    def audit_retention_years(self) -> int:
        return self.compliance.get("audit_retention_years", 7)

    def __repr__(self) -> str:
        return f"TenantConfig({self.tenant_id}, name={self.name}, wedges={self.enabled_wedges})"


class TenantManager:
    """
    Manages multi-tenant configurations and rule merging.

    Provides:
    - Tenant lookup and validation
    - Merged escalation rules (global + tenant custom)
    - Domain filtering (respect tenant disabled_domains)
    - Institution context for response generation
    """

    def __init__(self, config: DecisionConfigLoader):
        self._config = config
        self._tenants: Dict[str, TenantConfig] = {}

        for tid, raw in config.tenants.items():
            self._tenants[tid] = TenantConfig(tid, raw)

        logger.info("TenantManager initialized with %d tenants", len(self._tenants))

    @property
    def tenant_ids(self) -> List[str]:
        return sorted(self._tenants.keys())

    def get_tenant(self, tenant_id: str) -> Optional[TenantConfig]:
        return self._tenants.get(tenant_id)

    def get_merged_escalation_rules(
        self, tenant_id: str
    ) -> List[Dict[str, Any]]:
        """
        Merge global escalation rules with tenant-specific custom rules.

        Tenant rules are appended AFTER global rules, so they take effect
        as additional checks. Tenant rules with the same ID as global rules
        override the global version.
        """
        global_rules = list(self._config.risk_escalation_rules)
        tenant = self._tenants.get(tenant_id)
        if not tenant:
            return global_rules

        custom = tenant.custom_escalation_rules
        if not custom:
            return global_rules

        # Build a map of global rules by ID
        global_ids = {r.get("id"): i for i, r in enumerate(global_rules)}

        merged = list(global_rules)
        for rule in custom:
            rule_id = rule.get("id")
            if rule_id and rule_id in global_ids:
                # Override existing rule
                merged[global_ids[rule_id]] = rule
                logger.info(
                    "Tenant %s overrides global rule: %s", tenant_id, rule_id
                )
            else:
                # Append new rule
                merged.append(rule)
                logger.info(
                    "Tenant %s adds custom rule: %s", tenant_id, rule_id
                )

        return merged

    def get_enabled_domains(
        self, tenant_id: str, all_domains: Optional[List[str]] = None
    ) -> List[str]:
        """
        Get domains enabled for a tenant (all domains minus disabled ones).
        """
        if all_domains is None:
            all_domains = self._config.domain_names

        tenant = self._tenants.get(tenant_id)
        if not tenant:
            return all_domains

        disabled = tenant.disabled_domains
        if not disabled:
            return all_domains

        enabled = [d for d in all_domains if d not in disabled]
        logger.info(
            "Tenant %s: %d domains enabled (%d disabled: %s)",
            tenant_id,
            len(enabled),
            len(disabled),
            disabled,
        )
        return enabled

    def is_wedge_enabled(self, tenant_id: str, wedge_type: str) -> bool:
        """Check if a wedge/journey is enabled for a tenant."""
        tenant = self._tenants.get(tenant_id)
        if not tenant:
            return True  # No tenant config = all enabled
        return wedge_type in tenant.enabled_wedges

    def get_institution_context_for_prompts(
        self, tenant_id: str
    ) -> Dict[str, str]:
        """
        Get institution-specific context for LLM prompt injection.

        Returns strings that can be inserted into response specs.
        """
        tenant = self._tenants.get(tenant_id)
        if not tenant:
            return {
                "agent_name": "Avery",
                "institution_name": "your healthcare provider",
                "nurse_line": "the nurse line",
                "ed_name": "the emergency department",
            }

        return {
            "agent_name": "Avery",
            "institution_name": tenant.name,
            "nurse_line": tenant.nurse_line_number or "the nurse line",
            "ed_name": tenant.ed_name,
            "greeting": tenant.greeting_name,
        }