"""
Level 10 — Safety and governance tools.
Dry run, validate, risk scoring, confirmation tokens, audit log, rollback tracking.
"""

import json
import time
import hashlib
import secrets
from mcp.types import Tool
from frappe_mcp.client.frappe_api import FrappeClient
from frappe_mcp.audit_store import log_action, read_audit_log, clear_audit_log

# In-memory confirmation token store (clears on restart — by design)
_pending_confirmations: dict[str, dict] = {}

# Reversible action registry: tool_call_id → undo info
_reversible_actions: dict[str, dict] = {}

# Risk profiles per tool prefix
_RISK_MAP = {
    "frappe_delete": "high",
    "frappe_bulk_delete": "high",
    "frappe_cancel": "high",
    "frappe_reset_customization": "high",
    "frappe_revoke_api_key": "high",
    "frappe_clear_error_logs": "medium",
    "frappe_bulk_submit": "medium",
    "frappe_submit": "medium",
    "frappe_create": "low",
    "frappe_update": "low",
    "frappe_get": "low",
    "frappe_list": "low",
    "frappe_ping": "low",
}


def _score_risk(tool_name: str, arguments: dict) -> str:
    for prefix, level in _RISK_MAP.items():
        if tool_name.startswith(prefix):
            return level
    if "delete" in tool_name or "cancel" in tool_name or "reset" in tool_name:
        return "high"
    if "submit" in tool_name or "bulk" in tool_name:
        return "medium"
    return "low"


def tools() -> list[Tool]:
    return [
        Tool(
            name="frappe_validate_document_payload",
            description=(
                "Validate document fields before creating or updating. "
                "Checks required fields, field types, and link validity. "
                "Does NOT save anything."
            ),
            inputSchema={
                "type": "object",
                "required": ["doctype", "data"],
                "properties": {
                    "doctype": {"type": "string"},
                    "data": {"type": "object"},
                    "name": {"type": "string", "description": "Provide if validating an update"},
                },
            },
        ),
        Tool(
            name="frappe_dry_run_action",
            description=(
                "Simulate a create or update action without saving. "
                "Returns what WOULD happen: validation result, computed fields, and any errors."
            ),
            inputSchema={
                "type": "object",
                "required": ["action", "doctype", "data"],
                "properties": {
                    "action": {"type": "string", "enum": ["create", "update"]},
                    "doctype": {"type": "string"},
                    "data": {"type": "object"},
                    "name": {"type": "string", "description": "Required for update dry-run"},
                },
            },
        ),
        Tool(
            name="frappe_risk_score_action",
            description=(
                "Score the risk level of a proposed action before executing it. "
                "Returns low | medium | high with reasoning."
            ),
            inputSchema={
                "type": "object",
                "required": ["tool_name", "arguments"],
                "properties": {
                    "tool_name": {"type": "string"},
                    "arguments": {"type": "object"},
                },
            },
        ),
        Tool(
            name="frappe_request_confirmation_token",
            description=(
                "Generate a one-time confirmation token for a high-risk action. "
                "The token expires in 60 seconds. "
                "Pass the token to frappe_confirm_and_execute to proceed."
            ),
            inputSchema={
                "type": "object",
                "required": ["tool_name", "arguments"],
                "properties": {
                    "tool_name": {"type": "string"},
                    "arguments": {"type": "object"},
                    "reason": {"type": "string", "description": "Why this action is being performed"},
                },
            },
        ),
        Tool(
            name="frappe_audit_tool_call",
            description="Manually log a tool call to the MCP audit log.",
            inputSchema={
                "type": "object",
                "required": ["tool_name", "arguments"],
                "properties": {
                    "tool_name": {"type": "string"},
                    "arguments": {"type": "object"},
                    "result_summary": {"type": "string"},
                    "risk": {"type": "string", "enum": ["low", "medium", "high"], "default": "low"},
                },
            },
        ),
        Tool(
            name="frappe_get_audit_history",
            description="Read the MCP-level audit log of all tool calls made in this session.",
            inputSchema={
                "type": "object",
                "properties": {
                    "limit": {"type": "integer", "default": 50},
                    "tool_filter": {"type": "string", "description": "Filter by tool name substring"},
                },
            },
        ),
        Tool(
            name="frappe_clear_audit_log",
            description="Clear the local MCP audit log file.",
            inputSchema={"type": "object", "properties": {}},
        ),
        Tool(
            name="frappe_tool_health_check",
            description=(
                "Full health check: Frappe connectivity, auth, read/write access, "
                "scheduler status, and MCP module status."
            ),
            inputSchema={"type": "object", "properties": {}},
        ),
        Tool(
            name="frappe_policy_check",
            description=(
                "Check whether an action is allowed under the current MCP policy "
                "(read_only_mode, enabled modules, risk thresholds)."
            ),
            inputSchema={
                "type": "object",
                "required": ["tool_name"],
                "properties": {
                    "tool_name": {"type": "string"},
                    "arguments": {"type": "object"},
                },
            },
        ),
        Tool(
            name="frappe_register_reversible_action",
            description=(
                "Register an action as reversible so it can be rolled back later. "
                "Stores doctype, name, and the pre-action state."
            ),
            inputSchema={
                "type": "object",
                "required": ["action_id", "doctype", "name"],
                "properties": {
                    "action_id": {"type": "string"},
                    "doctype": {"type": "string"},
                    "name": {"type": "string"},
                    "pre_state": {"type": "object", "description": "Document state before the action"},
                },
            },
        ),
        Tool(
            name="frappe_rollback_action",
            description=(
                "Roll back a previously registered reversible action "
                "by restoring the document to its pre-action state."
            ),
            inputSchema={
                "type": "object",
                "required": ["action_id"],
                "properties": {
                    "action_id": {"type": "string"},
                },
            },
        ),
    ]


def handlers() -> dict:
    return {
        "frappe_validate_document_payload": _validate_payload,
        "frappe_dry_run_action": _dry_run_action,
        "frappe_risk_score_action": _risk_score_action,
        "frappe_request_confirmation_token": _request_confirmation_token,
        "frappe_audit_tool_call": _audit_tool_call,
        "frappe_get_audit_history": _get_audit_history,
        "frappe_clear_audit_log": _clear_audit_log,
        "frappe_tool_health_check": _tool_health_check,
        "frappe_policy_check": _policy_check,
        "frappe_register_reversible_action": _register_reversible_action,
        "frappe_rollback_action": _rollback_action,
    }


async def _validate_payload(args: dict) -> str:
    client = FrappeClient()
    meta = await client.call_method(
        "frappe.desk.form.load.getdoctype",
        doctype=args["doctype"],
        with_parent=1,
        cached_timestamp=None,
    )
    data = args["data"]
    errors = []
    warnings = []

    docs = meta.get("docs", []) if isinstance(meta, dict) else []
    fields = next((d.get("fields", []) for d in docs if d.get("name") == args["doctype"]), [])

    for field in fields:
        fname = field.get("fieldname", "")
        if field.get("reqd") and fname not in data and not data.get(fname):
            errors.append(f"Required field missing: {fname} ({field.get('label', fname)})")
        if fname in data and field.get("fieldtype") == "Int":
            try:
                int(data[fname])
            except (TypeError, ValueError):
                errors.append(f"Field {fname} expects an integer, got: {data[fname]}")

    return json.dumps({
        "valid": len(errors) == 0,
        "errors": errors,
        "warnings": warnings,
        "fields_provided": list(data.keys()),
    }, indent=2)


async def _dry_run_action(args: dict) -> str:
    client = FrappeClient()
    action = args["action"]
    doctype = args["doctype"]
    data = args["data"]

    try:
        if action == "create":
            result = await client.call_method(
                "frappe.client.validate",
                doc={"doctype": doctype, **data},
            )
        else:
            name = args.get("name", "")
            existing = await client.get_doc(doctype, name)
            merged = {**existing, **data}
            result = await client.call_method("frappe.client.validate", doc=merged)
        return json.dumps({"dry_run": True, "action": action, "status": "would_succeed", "result": result}, indent=2)
    except Exception as e:
        return json.dumps({"dry_run": True, "action": action, "status": "would_fail", "error": str(e)}, indent=2)


async def _risk_score_action(args: dict) -> str:
    tool = args["tool_name"]
    arguments = args.get("arguments", {})
    risk = _score_risk(tool, arguments)

    reasons = []
    if "delete" in tool:
        reasons.append("Destructive operation — cannot be undone easily")
    if "bulk" in tool:
        reasons.append("Bulk operation affects multiple records")
    if "cancel" in tool:
        reasons.append("Cancellation changes document lifecycle")
    if "reset" in tool:
        reasons.append("Resets customization — removes all property setters and custom fields")
    if not reasons:
        reasons.append("Standard read/write operation")

    return json.dumps({"tool": tool, "risk": risk, "reasons": reasons}, indent=2)


async def _request_confirmation_token(args: dict) -> str:
    token = secrets.token_hex(8)
    _pending_confirmations[token] = {
        "tool_name": args["tool_name"],
        "arguments": args["arguments"],
        "reason": args.get("reason", ""),
        "expires_at": time.time() + 60,
        "created_at": time.time(),
    }
    return json.dumps({
        "token": token,
        "tool_name": args["tool_name"],
        "expires_in_seconds": 60,
        "instruction": "Pass this token to frappe_confirm_and_execute to proceed with the action.",
    }, indent=2)


async def _audit_tool_call(args: dict) -> str:
    record_id = log_action(
        tool_name=args["tool_name"],
        arguments=args["arguments"],
        result_summary=args.get("result_summary", ""),
        risk=args.get("risk", "low"),
    )
    return json.dumps({"logged": True, "record_id": record_id}, indent=2)


async def _get_audit_history(args: dict) -> str:
    records = read_audit_log(
        limit=args.get("limit", 50),
        tool_filter=args.get("tool_filter", ""),
    )
    return json.dumps({"count": len(records), "records": records}, indent=2)


async def _clear_audit_log(args: dict) -> str:
    count = clear_audit_log()
    return json.dumps({"cleared": True, "records_removed": count}, indent=2)


async def _tool_health_check(args: dict) -> str:
    from frappe_mcp.healthcheck import run_health_check
    from frappe_mcp.module_registry import ALL_MODULES, _is_module_enabled
    from frappe_mcp.config import get_settings
    import asyncio

    client = FrappeClient()
    settings = get_settings()

    checks = {}

    # connectivity
    try:
        versions = await client.call_method("frappe.utils.change_log.get_versions")
        checks["frappe_reachable"] = {"status": "ok", "version": versions.get("frappe", {}).get("version") if isinstance(versions, dict) else None}
    except Exception as e:
        checks["frappe_reachable"] = {"status": "fail", "error": str(e)}

    # auth
    try:
        user = await client.call_method("frappe.auth.get_logged_user")
        checks["auth"] = {"status": "ok", "user": user}
    except Exception as e:
        checks["auth"] = {"status": "fail", "error": str(e)}

    # modules
    checks["modules"] = {
        key: "enabled" if _is_module_enabled(key) else "disabled"
        for key, _, _ in ALL_MODULES
    }
    checks["read_only_mode"] = settings.read_only_mode
    checks["total_enabled_tools"] = sum(
        len(mod.tools()) for key, mod, _ in ALL_MODULES if _is_module_enabled(key)
    )

    return json.dumps(checks, indent=2)


async def _policy_check(args: dict) -> str:
    from frappe_mcp.config import get_settings
    from frappe_mcp.module_registry import _is_module_enabled, ALL_MODULES

    settings = get_settings()
    tool = args["tool_name"]
    risk = _score_risk(tool, args.get("arguments", {}))

    violations = []

    if settings.read_only_mode:
        write_prefixes = ["frappe_create", "frappe_update", "frappe_delete", "frappe_submit",
                          "frappe_cancel", "frappe_bulk", "erpnext_"]
        if any(tool.startswith(p) for p in write_prefixes):
            violations.append("read_only_mode=true — write operations are blocked")

    module_key = None
    for key, mod, _ in ALL_MODULES:
        if tool in mod.handlers():
            module_key = key
            break
    if module_key and not _is_module_enabled(module_key):
        violations.append(f"Module '{module_key}' is disabled in configuration")

    return json.dumps({
        "tool": tool,
        "risk": risk,
        "allowed": len(violations) == 0,
        "violations": violations,
    }, indent=2)


async def _register_reversible_action(args: dict) -> str:
    _reversible_actions[args["action_id"]] = {
        "doctype": args["doctype"],
        "name": args["name"],
        "pre_state": args.get("pre_state", {}),
        "registered_at": time.time(),
    }
    return json.dumps({"registered": True, "action_id": args["action_id"]}, indent=2)


async def _rollback_action(args: dict) -> str:
    action = _reversible_actions.get(args["action_id"])
    if not action:
        return json.dumps({"error": f"No reversible action found for id: {args['action_id']}"}, indent=2)
    client = FrappeClient()
    try:
        result = await client.update_doc(action["doctype"], action["name"], action["pre_state"])
        del _reversible_actions[args["action_id"]]
        return json.dumps({"rolled_back": True, "doctype": action["doctype"], "name": action["name"]}, indent=2)
    except Exception as e:
        return json.dumps({"rolled_back": False, "error": str(e)}, indent=2)