"""
Tool registry for PrivilegeDesk.

All 19 tools are functions that take (world_state, arguments) and return:
    {
        "status": "success"|"error"|"permission_denied",
        "result": {...},
        "observations": ["Human-readable description of what happened"],
        "state_delta": {"dot.path.key": value, ...},  # mutations to apply
    }
"""
from datetime import datetime
from typing import Any, Dict


# ── Helpers ───────────────────────────────────────────────────────────────────

def _ok(result, observations, state_delta=None):
    return {"status": "success", "result": result,
            "observations": observations, "state_delta": state_delta or {}}

def _err(message):
    return {"status": "error", "result": {"error": message},
            "observations": [f"ERROR: {message}"], "state_delta": {}}


# ── Policy tools ──────────────────────────────────────────────────────────────

def policy_lookup(ws: Dict, args: Dict) -> Dict:
    """Look up policy for a resource."""
    resource_id = args.get("resource_id")
    if not resource_id:
        return _err("resource_id is required")
    policies = ws.get("policies", {})
    matching = [p for p in policies.values() if p["resource_id"] == resource_id]
    if not matching:
        return _ok({"policy": None}, [f"No policy found for resource {resource_id}"],
                   {"completion_state.subgoal_status.sg_lookup_policy": "completed"})
    policy = matching[0]
    return _ok(
        {"policy": policy},
        [f"Policy found: {policy['description']}"],
        {"completion_state.subgoal_status.sg_lookup_policy": "completed"},
    )

def policy_list(ws: Dict, args: Dict) -> Dict:
    """List all policies."""
    policies = ws.get("policies", {})
    return _ok(
        {"policies": list(policies.values()), "count": len(policies)},
        [f"Found {len(policies)} policies"],
        {"completion_state.subgoal_status.sg_lookup_policy": "completed"},
    )


# ── Org tools ─────────────────────────────────────────────────────────────────

def org_get_user(ws: Dict, args: Dict) -> Dict:
    """Get details for a specific user."""
    user_id = args.get("user_id")
    if not user_id:
        return _err("user_id is required")
    users = ws.get("users", {})
    user = users.get(user_id)
    if not user:
        return _err(f"User {user_id} not found")
    return _ok({"user": user}, [f"User: {user['name']} ({user['job_title']}, {user['department']})"])

def org_get_manager(ws: Dict, args: Dict) -> Dict:
    """Get the manager chain for a user."""
    user_id = args.get("user_id")
    if not user_id:
        return _err("user_id is required")
    users = ws.get("users", {})
    org_graph = ws.get("org_graph", {})
    chain = []
    current = user_id
    visited = set()
    while current and current not in visited:
        visited.add(current)
        mgr_id = org_graph.get(current, {}).get("reports_to")
        if mgr_id and mgr_id in users:
            chain.append({"user_id": mgr_id, "name": users[mgr_id]["name"],
                          "job_title": users[mgr_id]["job_title"]})
            current = mgr_id
        else:
            break
    return _ok(
        {"manager_chain": chain, "direct_manager_id": chain[0]["user_id"] if chain else None},
        [f"Manager chain for {user_id}: {[c['name'] for c in chain]}"],
        {"completion_state.subgoal_status.sg_find_approvers": "completed"},
    )

def org_list_users(ws: Dict, args: Dict) -> Dict:
    """List all users, optionally filtered by department."""
    dept = args.get("department")
    users = ws.get("users", {})
    if dept:
        filtered = {uid: u for uid, u in users.items() if u["department"] == dept}
    else:
        filtered = users
    summary = [{"user_id": uid, "name": u["name"], "department": u["department"],
                "job_title": u["job_title"]} for uid, u in filtered.items()]
    return _ok({"users": summary, "count": len(summary)},
               [f"Found {len(summary)} users{' in ' + dept if dept else ''}"])


# ── Request tools ─────────────────────────────────────────────────────────────

def request_view(ws: Dict, args: Dict) -> Dict:
    """View a specific pending request."""
    request_id = args.get("request_id")
    requests = ws.get("pending_requests", {})
    if request_id:
        req = requests.get(request_id)
        if not req:
            return _err(f"Request {request_id} not found")
    else:
        if not requests:
            return _ok({"request": None}, ["No pending requests"])
        req = next(iter(requests.values()))

    users = ws.get("users", {})
    requester = users.get(req["requester_id"], {})
    resources = ws.get("resources", {})
    resource = resources.get(req["resource_id"], {})

    return _ok(
        {"request": req,
         "requester": {"name": requester.get("name"), "department": requester.get("department")},
         "resource": {"name": resource.get("name"), "type": resource.get("type"),
                      "sensitivity": resource.get("sensitivity")}},
        [f"Request {req['request_id']}: {requester.get('name')} wants {req['requested_role']} "
         f"on {resource.get('name')} – reason: {req['reason']}"],
        {"completion_state.subgoal_status.sg_view_request": "completed"},
    )

def request_list(ws: Dict, args: Dict) -> Dict:
    """List all pending requests."""
    requests = ws.get("pending_requests", {})
    pending = [r for r in requests.values() if r["status"] == "pending"]
    return _ok(
        {"requests": pending, "count": len(pending)},
        [f"Found {len(pending)} pending request(s)"],
        {"completion_state.subgoal_status.sg_view_request": "completed"},
    )


# ── Approval tools ────────────────────────────────────────────────────────────

def approval_route(ws: Dict, args: Dict) -> Dict:
    """Route an access request to a specific approver."""
    request_id = args.get("request_id")
    approver_id = args.get("approver_id")
    if not request_id or not approver_id:
        return _err("request_id and approver_id are required")

    chains = ws.get("approval_chains", {})
    chain_info = chains.get(request_id)
    if not chain_info:
        return _err(f"No approval chain found for request {request_id}")

    users = ws.get("users", {})
    approver = users.get(approver_id, {})
    hidden = ws.get("hidden_state", {})
    correct_chain = hidden.get("correct_approval_chains", {}).get(request_id, [])
    current_step = chain_info.get("current_step", 0)

    is_correct = (current_step < len(correct_chain) and
                  correct_chain[current_step] == approver_id)

    step_reward_key = "sg_route_approvals"
    if is_correct:
        # Auto-approve for simulation
        chain_info["approver_chain"][current_step]["status"] = "approved"
        chain_info["current_step"] = current_step + 1
        all_approved = all(s["status"] == "approved" for s in chain_info["approver_chain"])
        obs = [f"Routed to {approver.get('name', approver_id)} — APPROVED ✓"]
        if all_approved:
            ws["pending_requests"][request_id]["status"] = "approved"
            obs.append("All approvals collected. Request is fully approved.")
    else:
        obs = [f"Routed to {approver.get('name', approver_id)} — wrong approver for this step"]

    # Track routed approvals
    routed = ws.get("completion_state", {}).get("approvals_routed", [])
    routed.append({"request_id": request_id, "approver_id": approver_id, "correct": is_correct})

    return _ok(
        {"request_id": request_id, "approver_id": approver_id,
         "correct": is_correct, "chain_state": chain_info},
        obs,
        {
            "approval_chains": chains,
            "completion_state.approvals_routed": routed,
            "completion_state.subgoal_status.sg_route_approvals": "completed",
            "completion_state.subgoal_status.sg_find_approvers": "completed",
        },
    )

def approval_check_status(ws: Dict, args: Dict) -> Dict:
    """Check the approval status for a request."""
    request_id = args.get("request_id")
    if not request_id:
        return _err("request_id is required")
    chains = ws.get("approval_chains", {})
    chain = chains.get(request_id, {})
    req = ws.get("pending_requests", {}).get(request_id, {})
    return _ok(
        {"status": req.get("status", "pending"), "chain": chain},
        [f"Request {request_id} status: {req.get('status', 'pending')}"],
    )


# ── Access tools ──────────────────────────────────────────────────────────────

def access_decide(ws: Dict, args: Dict) -> Dict:
    """Submit an approve/deny decision for an access request (Task 1)."""
    request_id = args.get("request_id")
    decision = args.get("decision")  # "approve" | "deny"
    role = args.get("role")
    ttl_hours = args.get("ttl_hours")
    justification_category = args.get("justification_category", "operational")

    if not decision:
        return _err("decision is required (approve or deny)")

    requests = ws.get("pending_requests", {})
    # If no request_id given (or it's not found), auto-pick the first pending one
    if not request_id or request_id not in requests:
        request_id = next(
            (rid for rid, r in requests.items() if r.get("status") == "pending"),
            next(iter(requests), None),
        )
        if not request_id:
            return _err("No pending requests found")

    requests[request_id]["status"] = "approved" if decision == "approve" else "denied"
    requests[request_id]["_agent_decision"] = {
        "decision": decision,
        "role": role,
        "ttl_hours": ttl_hours,
        "justification_category": justification_category,
    }

    return _ok(
        {"request_id": request_id, "decision": decision, "role": role, "ttl_hours": ttl_hours},
        [f"Decision submitted: {decision.upper()} for {request_id} "
         f"(role={role}, ttl={ttl_hours}h)"],
        {
            "pending_requests": requests,
            "completion_state.decision_submitted": True,
            "_terminated": True,  # Task 1 ends after a decision
        },
    )

def access_grant(ws: Dict, args: Dict) -> Dict:
    """Activate an approved temporary access grant (Task 2)."""
    request_id = args.get("request_id")
    if not request_id:
        return _err("request_id is required")
    req = ws.get("pending_requests", {}).get(request_id, {})
    if req.get("status") != "approved":
        return _ok(
            {"activated": False},
            [f"Cannot grant: request {request_id} is not approved (status={req.get('status')})"],
        )

    return _ok(
        {"activated": True, "request_id": request_id},
        [f"Grant activated for request {request_id}"],
        {
            "completion_state.grant_activated": True,
            "completion_state.subgoal_status.sg_activate_grant": "completed",
            "_terminated": True,  # Task 2 ends after activation
        },
    )

def access_set_ttl(ws: Dict, args: Dict) -> Dict:
    """Set the TTL on a pending grant."""
    request_id = args.get("request_id")
    ttl_hours = args.get("ttl_hours")
    if not request_id or ttl_hours is None:
        return _err("request_id and ttl_hours are required")
    requests = ws.get("pending_requests", {})
    if request_id in requests:
        requests[request_id]["_agent_ttl"] = ttl_hours
    return _ok(
        {"request_id": request_id, "ttl_hours": ttl_hours},
        [f"TTL set to {ttl_hours}h for request {request_id}"],
        {
            "pending_requests": requests,
            "completion_state.subgoal_status.sg_set_ttl": "completed",
        },
    )


# ── Entitlement tools ─────────────────────────────────────────────────────────

def entitlement_list(ws: Dict, args: Dict) -> Dict:
    """List entitlements, optionally filtered by user_id."""
    user_id = args.get("user_id")
    entitlements = ws.get("entitlements", {})
    if user_id:
        filtered = {eid: e for eid, e in entitlements.items() if e["user_id"] == user_id}
    else:
        filtered = entitlements

    # Return sanitized view (no hidden _is_risky fields)
    visible = [{k: v for k, v in e.items() if not k.startswith("_")}
               for e in filtered.values()]

    return _ok(
        {"entitlements": visible, "count": len(visible)},
        [f"Found {len(visible)} entitlement(s){' for user ' + user_id if user_id else ''}"],
        {
            "completion_state.subgoal_status.sg_list_entitlements": "completed",
            "completion_state.subgoal_status.sg_check_existing": "completed",
        },
    )

def entitlement_inspect(ws: Dict, args: Dict) -> Dict:
    """Inspect a specific entitlement — reveals risky flags if applicable."""
    entitlement_id = args.get("entitlement_id")
    if not entitlement_id:
        return _err("entitlement_id is required")
    entitlements = ws.get("entitlements", {})
    ent = entitlements.get(entitlement_id)
    if not ent:
        return _err(f"Entitlement {entitlement_id} not found")

    now = datetime.fromisoformat(ws.get("current_time", datetime.now().isoformat()))
    resources = ws.get("resources", {})
    resource = resources.get(ent["resource_id"], {})
    users = ws.get("users", {})
    user = users.get(ent["user_id"], {})

    # Reveal risky signals (but not the raw _is_risky flag)
    warnings = []
    if ent.get("_risky_reason") == "over_privileged":
        warnings.append(f"⚠️ User has '{ent['role']}' but resource policy may allow lower role")
    if ent.get("_risky_reason") == "expired_ttl" and ent.get("expires_at"):
        warnings.append(f"⚠️ TTL expired at {ent['expires_at']} — grant should have been revoked")
    if ent.get("days_since_use", 0) > 90:
        warnings.append(f"⚠️ Last used {ent['days_since_use']} days ago — potential stale access")
    if user.get("status") == "inactive":
        warnings.append(f"⚠️ User {user.get('name')} is inactive — orphaned entitlement")

    return _ok(
        {"entitlement": {k: v for k, v in ent.items() if not k.startswith("_")},
         "resource": {"name": resource.get("name"), "sensitivity": resource.get("sensitivity")},
         "user": {"name": user.get("name"), "status": user.get("status")},
         "warnings": warnings},
        ([f"Entitlement {entitlement_id}: {user.get('name')} has '{ent['role']}' on {resource.get('name')}"] +
         warnings),
        {"completion_state.subgoal_status.sg_identify_risky": "in_progress"},
    )

def entitlement_revoke(ws: Dict, args: Dict) -> Dict:
    """Revoke a specific entitlement."""
    entitlement_id = args.get("entitlement_id")
    reason = args.get("reason", "access_review")
    if not entitlement_id:
        return _err("entitlement_id is required")
    entitlements = ws.get("entitlements", {})
    if entitlement_id not in entitlements:
        return _err(f"Entitlement {entitlement_id} not found")

    entitlements[entitlement_id]["status"] = "revoked"
    revoked = ws.get("completion_state", {}).get("entitlements_revoked", [])
    revoked.append(entitlement_id)

    return _ok(
        {"revoked": entitlement_id, "reason": reason},
        [f"Entitlement {entitlement_id} revoked (reason: {reason})"],
        {
            "entitlements": entitlements,
            "completion_state.entitlements_revoked": revoked,
            "completion_state.subgoal_status.sg_revoke_correctly": "in_progress",
        },
    )


# ── Audit tools ───────────────────────────────────────────────────────────────

def audit_query(ws: Dict, args: Dict) -> Dict:
    """Query the pre-existing audit log."""
    user_id = args.get("user_id")
    resource_id = args.get("resource_id")
    days = args.get("days", 90)

    audit_db = ws.get("audit_db", [])
    now = datetime.fromisoformat(ws.get("current_time", datetime.now().isoformat()))

    results = []
    for entry in audit_db:
        ts = datetime.fromisoformat(entry["timestamp"])
        if (now - ts).days > days:
            continue
        if user_id and entry["user_id"] != user_id:
            continue
        if resource_id and entry["resource_id"] != resource_id:
            continue
        results.append(entry)

    return _ok(
        {"entries": results[:20], "count": len(results)},
        [f"Found {len(results)} audit entries"
         + (f" for user {user_id}" if user_id else "")
         + (f" on resource {resource_id}" if resource_id else "")],
        {"completion_state.subgoal_status.sg_query_audit": "completed"},
    )


# ── Group tools ───────────────────────────────────────────────────────────────

def group_resolve(ws: Dict, args: Dict) -> Dict:
    """Resolve group membership and show inherited entitlements."""
    group_id = args.get("group_id")
    user_id = args.get("user_id")  # or resolve groups for a specific user

    groups = ws.get("groups", {})
    entitlements = ws.get("entitlements", {})

    if group_id:
        group = groups.get(group_id)
        if not group:
            return _err(f"Group {group_id} not found")
        members = group.get("members", [])
        inherited = {eid: e for eid, e in entitlements.items()
                     if e["source"] == "group_inherited" and e["user_id"] in members}
        return _ok(
            {"group": group, "members": members, "inherited_entitlements": list(inherited.values())},
            [f"Group {group['name']}: {len(members)} members, {len(inherited)} inherited entitlements"],
            {"completion_state.subgoal_status.sg_resolve_groups": "completed"},
        )
    elif user_id:
        user_groups = [g for g in groups.values() if user_id in g.get("members", [])]
        inherited = {eid: e for eid, e in entitlements.items()
                     if e["source"] == "group_inherited" and e["user_id"] == user_id}
        return _ok(
            {"user_id": user_id, "groups": user_groups, "inherited_entitlements": list(inherited.values())},
            [f"User {user_id} is in {len(user_groups)} group(s) with {len(inherited)} inherited entitlements"],
            {"completion_state.subgoal_status.sg_resolve_groups": "completed"},
        )
    else:
        return _err("group_id or user_id is required")


# ── Workflow tools ────────────────────────────────────────────────────────────

def workflow_check_active(ws: Dict, args: Dict) -> Dict:
    """Check if a user has active workflows that depend on an entitlement."""
    user_id = args.get("user_id")
    entitlement_id = args.get("entitlement_id")

    workflows = ws.get("workflows", {})
    relevant = []

    for wf in workflows.values():
        match_user = (not user_id or wf.get("user_id") == user_id)
        match_ent = (not entitlement_id or
                     entitlement_id in wf.get("depends_on_entitlements", []))
        if match_user and match_ent and wf.get("is_active"):
            relevant.append(wf)

    return _ok(
        {"active_workflows": relevant, "count": len(relevant),
         "safe_to_revoke": len(relevant) == 0},
        [f"Found {len(relevant)} active workflow(s) depending on this entitlement"
         + (" — SAFE to revoke" if len(relevant) == 0 else " — WARNING: revocation may break workflows")],
        {"completion_state.subgoal_status.sg_check_workflows": "completed"},
    )


# ── Review tools ──────────────────────────────────────────────────────────────

def review_submit(ws: Dict, args: Dict) -> Dict:
    """Submit the completed access review."""
    summary = args.get("summary", "")
    revoked = ws.get("completion_state", {}).get("entitlements_revoked", [])

    return _ok(
        {"submitted": True,
         "entitlements_revoked": revoked,
         "count_revoked": len(revoked),
         "summary": summary},
        [f"Access review submitted. Revoked {len(revoked)} entitlement(s)."],
        {
            "completion_state.review_submitted": True,
            "completion_state.subgoal_status.sg_submit_review": "completed",
            "_terminated": True,
        },
    )


# ── Tool Registry ─────────────────────────────────────────────────────────────

TOOL_REGISTRY: Dict[str, Any] = {
    "policy.lookup":            policy_lookup,
    "policy.list":              policy_list,
    "org.get_user":             org_get_user,
    "org.get_manager":          org_get_manager,
    "org.list_users":           org_list_users,
    "request.view":             request_view,
    "request.list":             request_list,
    "approval.route":           approval_route,
    "approval.check_status":    approval_check_status,
    "access.decide":            access_decide,
    "access.grant":             access_grant,
    "access.set_ttl":           access_set_ttl,
    "entitlement.list":         entitlement_list,
    "entitlement.inspect":      entitlement_inspect,
    "entitlement.revoke":       entitlement_revoke,
    "audit.query":              audit_query,
    "group.resolve":            group_resolve,
    "workflow.check_active":    workflow_check_active,
    "review.submit":            review_submit,
}


def get_available_tools(task_available: list = None) -> list:
    if task_available:
        return [t for t in task_available if t in TOOL_REGISTRY]
    return list(TOOL_REGISTRY.keys())