{%- macro format_argument(argument, escape_keys=True) -%}
    {%- if argument is none -%}
        {{- 'null' -}}
    {%- elif argument is string -%}
        {{- '<|"|>' + argument + '<|"|>' -}}
    {%- elif argument is boolean -%}
        {{- 'true' if argument else 'false' -}}
    {%- elif argument is mapping -%}
        {{- '{' -}}
        {%- set ns = namespace(found_first=false) -%}
        {%- for key, value in argument | dictsort -%}
            {%- if ns.found_first %},{% endif -%}
            {%- set ns.found_first = true -%}
            {%- if escape_keys -%}
                {{- '<|"|>' + key + '<|"|>' -}}
            {%- else -%}
                {{- key -}}
            {%- endif -%}
            :{{- format_argument(value, escape_keys=escape_keys) -}}
        {%- endfor -%}
        {{- '}' -}}
    {%- elif argument is iterable and argument is not string -%}
        {{- '[' -}}
        {%- for item in argument -%}
            {{- format_argument(item, escape_keys=escape_keys) -}}
            {%- if not loop.last %},{% endif -%}
        {%- endfor -%}
        {{- ']' -}}
    {%- else -%}
        {{- argument -}}
    {%- endif -%}
{%- endmacro -%}

{%- macro format_type_argument(type_value) -%}
    {%- if type_value is none -%}
        <|"|>OBJECT<|"|>
    {%- elif type_value is string -%}
        <|"|>{{ type_value | upper }}<|"|>
    {%- elif type_value is iterable and type_value is not string -%}
        [
        {%- for item in type_value -%}
            {%- if item is string -%}
                <|"|>{{ item | upper }}<|"|>
            {%- else -%}
                {{- format_argument(item) -}}
            {%- endif -%}
            {%- if not loop.last %},{% endif -%}
        {%- endfor -%}
        ]
    {%- else -%}
        {{- format_argument(type_value) -}}
    {%- endif -%}
{%- endmacro -%}

{%- macro format_parameters(properties, required, filter_keys=false) -%}
    {%- set standard_keys = ['description', 'type', 'properties', 'required', 'nullable'] -%}
    {%- set ns = namespace(found_first=false) -%}
    {%- for key, value in properties | dictsort -%}
        {%- if not filter_keys or key not in standard_keys -%}
            {%- if ns.found_first %},{% endif -%}
            {%- set ns.found_first = true -%}
            {{ key }}:{
            {%- set add_comma = false -%}
            {%- if value is mapping -%}
                {%- set vtype = value['type'] if 'type' in value and value['type'] else none -%}
                {%- set is_string_type = (vtype is string and vtype | upper == 'STRING') or (vtype is iterable and vtype is not string and ('string' in vtype or 'STRING' in vtype)) -%}
                {%- set is_array_type = (vtype is string and vtype | upper == 'ARRAY') or (vtype is iterable and vtype is not string and ('array' in vtype or 'ARRAY' in vtype)) -%}
                {%- set is_object_type = (vtype is string and vtype | upper == 'OBJECT') or (vtype is iterable and vtype is not string and ('object' in vtype or 'OBJECT' in vtype)) -%}
                {%- if 'description' in value and value['description'] -%}
                    description:<|"|>{{ value['description'] }}<|"|>
                    {%- set add_comma = true -%}
                {%- endif -%}
                {%- if is_string_type -%}
                    {%- if 'enum' in value and value['enum'] -%}
                        {%- if add_comma %},{%- else -%} {%- set add_comma = true -%} {% endif -%}
                        enum:{{ format_argument(value['enum']) }}
                    {%- endif -%}
                {%- elif is_array_type -%}
                    {%- if 'items' in value and value['items'] is mapping and value['items'] -%}
                        {%- if add_comma %},{%- else -%} {%- set add_comma = true -%} {% endif -%}
                        items:{
                        {%- set ns_items = namespace(found_first=false) -%}
                        {%- for item_key, item_value in value['items'] | dictsort -%}
                            {%- if item_value is not none -%}
                                {%- if ns_items.found_first %},{% endif -%}
                                {%- set ns_items.found_first = true -%}
                                {%- if item_key == 'properties' -%}
                                    properties:{
                                    {%- if item_value is mapping -%}
                                        {{- format_parameters(item_value, value['items']['required'] if 'required' in value['items'] else []) -}}
                                    {%- endif -%}
                                    }
                                {%- elif item_key == 'required' -%}
                                    required:[
                                    {%- for req_item in item_value -%}
                                        <|"|>{{- req_item -}}<|"|>
                                        {%- if not loop.last %},{% endif -%}
                                    {%- endfor -%}
                                    ]
                                {%- elif item_key == 'type' -%}
                                    type:{{ format_type_argument(item_value) }}
                                {%- else -%}
                                    {{ item_key }}:{{ format_argument(item_value) }}
                                {%- endif -%}
                            {%- endif -%}
                        {%- endfor -%}
                        }
                    {%- endif -%}
                {%- endif -%}
                {%- if 'nullable' in value and value['nullable'] -%}
                    {%- if add_comma %},{%- else -%} {%- set add_comma = true -%} {% endif -%}
                    nullable:true
                {%- endif -%}
                {%- if is_object_type or ('properties' in value and value['properties'] is mapping) -%}
                    {%- if 'properties' in value and value['properties'] is mapping -%}
                        {%- if add_comma %},{%- else -%} {%- set add_comma = true -%} {% endif -%}
                        properties:{
                        {{- format_parameters(value['properties'], value['required'] if 'required' in value else []) -}}
                        }
                    {%- elif value is mapping -%}
                        {%- if add_comma %},{%- else -%} {%- set add_comma = true -%} {% endif -%}
                        properties:{
                        {{- format_parameters(value, value['required'] if 'required' in value else [], filter_keys=true) -}}
                        }
                    {%- endif -%}
                    {%- if 'required' in value and value['required'] -%}
                        {%- if add_comma %},{%- else -%} {%- set add_comma = true -%} {% endif -%}
                        required:[
                        {%- for item in value['required'] -%}
                            <|"|>{{- item -}}<|"|>
                            {%- if not loop.last %},{% endif -%}
                        {%- endfor -%}
                        ]
                    {%- endif -%}
                {%- endif -%}
                {%- if add_comma %},{%- else -%} {%- set add_comma = true -%} {% endif -%}
                type:{{ format_type_argument(vtype if vtype else 'object') }}
            {%- else -%}
                type:{{ format_type_argument('object') }}
            {%- endif -%}
            }
        {%- endif -%}
    {%- endfor -%}
{%- endmacro -%}

{%- macro format_function_declaration(tool_data) -%}
    {%- set fn = tool_data['function'] if tool_data is mapping and 'function' in tool_data else tool_data -%}
    {%- set tool_name = fn['name'] if fn is mapping and 'name' in fn and fn['name'] else 'unknown' -%}
    {%- set tool_description = fn['description'] if fn is mapping and 'description' in fn and fn['description'] else '' -%}
    declaration:{{- tool_name -}}{description:<|"|>{{- tool_description -}}<|"|>
    {%- set params = none -%}
    {%- if fn is mapping and 'parameters' in fn and fn['parameters'] -%}
        {%- set params = fn['parameters'] -%}
    {%- elif fn is mapping and 'input_schema' in fn and fn['input_schema'] -%}
        {%- set params = fn['input_schema'] -%}
    {%- elif fn is mapping and 'inputSchema' in fn and fn['inputSchema'] -%}
        {%- set params = fn['inputSchema'] -%}
    {%- endif -%}
    {%- if params and params is mapping -%}
        ,parameters:{
        {%- if 'properties' in params and params['properties'] -%}
            properties:{ {{- format_parameters(params['properties'], params['required'] if 'required' in params else []) -}} },
        {%- endif -%}
        {%- if 'required' in params and params['required'] -%}
            required:[
            {%- for item in params['required'] -%}
                <|"|>{{- item -}}<|"|>
                {{- ',' if not loop.last -}}
            {%- endfor -%}
            ],
        {%- endif -%}
        {%- if 'type' in params and params['type'] -%}
            type:{{- format_type_argument(params['type']) -}}}
        {%- else -%}
            type:{{- format_type_argument('object') -}}}
        {%- endif -%}
    {%- endif -%}
    {%- if fn is mapping and 'response' in fn and fn['response'] is mapping -%}
        {%- set response_declaration = fn['response'] -%}
        ,response:{
        {%- if 'description' in response_declaration and response_declaration['description'] -%}
            description:<|"|>{{- response_declaration['description'] -}}<|"|>,
        {%- endif -%}
        {%- if 'type' in response_declaration and response_declaration['type'] -%}
            type:{{- format_type_argument(response_declaration['type']) -}}}
        {%- else -%}
            type:{{- format_type_argument('object') -}}}
        {%- endif -%}
    {%- endif -%}
    }
{%- endmacro -%}

{%- macro strip_thinking(text) -%}
    {{- text | trim -}}
{%- endmacro -%}

{%- macro format_tool_response_block(tool_name, response) -%}
    {{- '<|tool_response>' -}}
    {%- if response is mapping -%}
        {{- 'response:' + tool_name + '{' -}}
        {%- for key, value in response | dictsort -%}
            {{- key -}}:{{- format_argument(value, escape_keys=False) -}}
            {%- if not loop.last %},{% endif -%}
        {%- endfor -%}
        {{- '}' -}}
    {%- else -%}
        {{- 'response:' + tool_name + '{value:' + format_argument(response, escape_keys=False) + '}' -}}
    {%- endif -%}
    {{- '<tool_response|>' -}}
{%- endmacro -%}

{#- ===== SETUP ===== -#}
{%- set ns = namespace(prev_message_type=None, prev_non_tool_role=None) -%}
{%- set loop_messages = messages -%}
{%- set enable_thinking = enable_thinking if enable_thinking is defined else false -%}
{%- set preserve_thinking = preserve_thinking if preserve_thinking is defined else true -%}
{{- bos_token -}}
{#- Handle System/Tool Definitions Block -#}
{%- if enable_thinking or (tools is defined and tools) or (messages and messages[0]['role'] in ['system', 'developer']) -%}
    {{- '<|turn>system\n' -}}
    {#- Inject Thinking token at the very top of the FIRST system turn -#}
    {%- if enable_thinking -%}
        {{- '<|think|>\n' -}}
        {%- set ns.prev_message_type = 'think' -%}
    {%- endif -%}
    {%- if messages and messages[0]['role'] in ['system', 'developer'] -%}
        {%- if messages[0]['content'] is string -%}
            {{- messages[0]['content'] | trim -}}
        {%- elif messages[0]['content'] is iterable and messages[0]['content'] is not string -%}
            {%- for item in messages[0]['content'] -%}
                {%- if item is mapping and 'text' in item -%}{{- item['text'] | trim + ' '-}}{%- endif -%}
            {%- endfor -%}
        {%- endif -%}
        {%- set loop_messages = messages[1:] -%}
    {%- endif -%}
    {%- if tools is defined and tools -%}
        {%- for tool in tools %}
            {{- '<|tool>' -}}
            {{- format_function_declaration(tool) | trim -}}
            {{- '<tool|>' -}}
        {%- endfor %}
        {%- set ns.prev_message_type = 'tool' -%}
    {%- endif -%}
    {{- '<turn|>\n' -}}
{%- endif %}

{#- Pre-scan: find last user message index for reasoning guard -#}
{%- set ns_turn = namespace(last_user_idx=-1) -%}
{%- for i in range(loop_messages | length) -%}
    {%- if loop_messages[i]['role'] == 'user' -%}
        {%- set ns_turn.last_user_idx = i -%}
    {%- endif -%}
{%- endfor -%}

{#- Loop through messages -#}
{%- for message in loop_messages -%}
    {%- if message['role'] != 'tool' -%}
    {%- set ns.prev_message_type = None -%}
    {%- set role = 'model' if message['role'] == 'assistant' else message['role'] -%}
    {%- set message_has_tool_calls = ('tool_calls' in message and message['tool_calls']) -%}
    {#- Detect continuation using tracked state — O(1) instead of O(n) backward scan -#}
    {%- set continue_same_model_turn = (role == 'model' and ns.prev_non_tool_role == 'assistant') -%}
    {%- if not continue_same_model_turn -%}
        {{- '<|turn>' + role + '\n' }}
    {%- endif -%}

    {#- Render reasoning/reasoning_content as thinking channel (tool-call turns only) -#}
    {%- set thinking_ns = namespace(text='') -%}
    {%- if 'reasoning' in message and message['reasoning'] -%}
        {%- set thinking_ns.text = message['reasoning'] -%}
    {%- elif 'reasoning_content' in message and message['reasoning_content'] -%}
        {%- set thinking_ns.text = message['reasoning_content'] -%}
    {%- endif -%}
    {%- set thinking_gate = (loop.index0 > ns_turn.last_user_idx) or preserve_thinking -%}
    {%- if thinking_ns.text and thinking_gate and message_has_tool_calls -%}
        {{- '<|channel>thought\n' + thinking_ns.text + '\n<channel|>' -}}
    {%- endif -%}

            {%- if message_has_tool_calls -%}
                {%- for tool_call in message['tool_calls'] -%}
                    {%- set function = tool_call['function'] if tool_call is mapping and 'function' in tool_call else tool_call -%}
                    {%- set function_name = function['name'] if function is mapping and 'name' in function and function['name'] else 'unknown' -%}
                    {{- '<|tool_call>call:' + function_name + '{' -}}
                    {%- if function is mapping and 'arguments' in function and function['arguments'] is mapping -%}
                        {%- set ns_args = namespace(found_first=false) -%}
                        {%- for key, value in function['arguments'] | dictsort -%}
                            {%- if ns_args.found_first %},{% endif -%}
                            {%- set ns_args.found_first = true -%}
                            {{- key -}}:{{- format_argument(value, escape_keys=False) -}}
                        {%- endfor -%}
                    {%- elif function is mapping and 'arguments' in function and function['arguments'] is string -%}
                        {{- function['arguments'] -}}
                    {%- elif function is mapping and 'arguments' in function and function['arguments'] is not none -%}
                        {{- format_argument(function['arguments'], escape_keys=False) -}}
                    {%- endif -%}
                    {{- '}<tool_call|>' -}}
                {%- endfor -%}
                {%- set ns.prev_message_type = 'tool_call' -%}
            {%- endif -%}

            {%- set ns_tr_out = namespace(flag=false) -%}
            {%- if 'tool_responses' in message and message['tool_responses'] -%}
                {#- Legacy: tool_responses embedded on the assistant message (Google/Gemma native) -#}
                {%- for tool_response in message['tool_responses'] -%}
                    {%- set tr_name = tool_response['name'] if tool_response is mapping and 'name' in tool_response and tool_response['name'] else 'unknown' -%}
                    {%- set tr_response = tool_response['response'] if tool_response is mapping and 'response' in tool_response else '' -%}
                    {{- format_tool_response_block(tr_name, tr_response) -}}
                    {%- set ns_tr_out.flag = true -%}
                    {%- set ns.prev_message_type = 'tool_response' -%}
                {%- endfor -%}
            {%- elif message_has_tool_calls -%}
                {#- OpenAI Chat Completions: forward-scan consecutive role:tool messages -#}
                {%- set ns_tool_scan = namespace(stopped=false) -%}
                {%- for k in range(loop.index0 + 1, loop_messages | length) -%}
                    {%- if ns_tool_scan.stopped -%}
                    {%- elif loop_messages[k]['role'] != 'tool' -%}
                        {%- set ns_tool_scan.stopped = true -%}
                    {%- else -%}
                        {%- set follow = loop_messages[k] -%}
                        {#- Resolve tool_call_id to function name -#}
                        {%- set ns_tname = namespace(name='unknown') -%}
                        {%- if 'name' in follow and follow['name'] -%}
                            {%- set ns_tname.name = follow['name'] -%}
                        {%- endif -%}
                        {%- for tc in message['tool_calls'] -%}
                            {%- if tc is mapping and 'id' in tc and 'tool_call_id' in follow and tc['id'] == follow['tool_call_id'] -%}
                                {%- if 'function' in tc and 'name' in tc['function'] and tc['function']['name'] -%}
                                    {%- set ns_tname.name = tc['function']['name'] -%}
                                {%- elif 'name' in tc and tc['name'] -%}
                                    {%- set ns_tname.name = tc['name'] -%}
                                {%- endif -%}
                            {%- endif -%}
                        {%- endfor -%}
                        {#- Handle content as string, object, or content-parts array -#}
                        {%- set tool_body = follow['content'] if 'content' in follow else '' -%}
                        {%- if tool_body is string -%}
                            {{- format_tool_response_block(ns_tname.name, tool_body) -}}
                        {%- elif tool_body is mapping -%}
                            {{- format_tool_response_block(ns_tname.name, tool_body) -}}
                        {%- elif tool_body is iterable and tool_body is not string -%}
                            {%- set ns_txt = namespace(s='') -%}
                            {%- for part in tool_body -%}
                                {%- if part is mapping and 'type' in part and part['type'] == 'text' and 'text' in part -%}
                                    {%- set ns_txt.s = ns_txt.s + part['text'] -%}
                                {%- endif -%}
                            {%- endfor -%}
                            {{- format_tool_response_block(ns_tname.name, ns_txt.s) -}}
                            {%- for part in tool_body -%}
                                {%- if part is mapping and 'type' in part and part['type'] in ['image', 'image_url'] -%}
                                    {{- '<|image|>' -}}
                                {%- elif part is mapping and 'type' in part and part['type'] in ['audio', 'input_audio'] -%}
                                    {{- '<|audio|>' -}}
                                {%- elif part is mapping and 'type' in part and part['type'] == 'video' -%}
                                    {{- '<|video|>' -}}
                                {%- endif -%}
                            {%- endfor -%}
                        {%- else -%}
                            {{- format_tool_response_block(ns_tname.name, tool_body) -}}
                        {%- endif -%}
                        {%- set ns_tr_out.flag = true -%}
                        {%- set ns.prev_message_type = 'tool_response' -%}
                    {%- endif -%}
                {%- endfor -%}
            {%- endif -%}

            {%- set captured_content -%}
            {%- if 'content' in message and message['content'] is string -%}
                {%- if role == 'model' -%}
                    {{- strip_thinking(message['content']) -}}
                {%- else -%}
                    {{- message['content'] | trim -}}
                {%- endif -%}
            {%- elif 'content' in message and message['content'] is iterable and message['content'] is not string -%}
                {%- for item in message['content'] -%}
                    {%- if item is mapping and 'type' in item and item['type'] == 'text' and 'text' in item -%}
                        {%- if role == 'model' -%}
                            {{- strip_thinking(item['text']) -}}
                        {%- else -%}
                            {{- item['text'] | trim -}}
                        {%- endif -%}
                    {%- elif item is mapping and 'type' in item and item['type'] in ['image', 'image_url'] -%}
                        {{- '<|image|>' -}}
                    {%- elif item is mapping and 'type' in item and item['type'] in ['audio', 'input_audio'] -%}
                        {{- '<|audio|>' -}}
                    {%- elif item is mapping and 'type' in item and item['type'] == 'video' -%}
                        {{- '<|video|>' -}}
                    {%- endif -%}
                {%- endfor -%}
            {%- endif -%}
            {%- endset -%}

            {{- captured_content -}}
            {%- set has_content = captured_content | trim | length > 0 -%}

        {#- Forward-scan: find next non-tool message role for continuation detection -#}
        {%- set next_nt = namespace(role=None, found=false) -%}
        {%- for j in range(loop.index0 + 1, loop_messages | length) -%}
            {%- if not next_nt.found -%}
                {%- if loop_messages[j]['role'] != 'tool' -%}
                    {%- set next_nt.role = loop_messages[j]['role'] -%}
                    {%- set next_nt.found = true -%}
                {%- endif -%}
            {%- endif -%}
        {%- endfor -%}

        {%- set continues_into_next = (
            role == 'model'
            and next_nt.role == 'assistant'
            and not message_has_tool_calls
            and not ns_tr_out.flag
        ) -%}

        {%- if ns.prev_message_type == 'tool_call' and not ns_tr_out.flag -%}
            {{- '<|tool_response>' -}}
        {%- elif continues_into_next -%}
            {{- '\n' -}}
        {%- elif not (ns_tr_out.flag and not has_content) -%}
            {{- '<turn|>\n' -}}
        {%- endif -%}

    {#- Track previous non-tool role for next iteration (avoids O(n) backward scan) -#}
    {%- set ns.prev_non_tool_role = message['role'] -%}
    {%- endif -%}
{%- endfor -%}

{%- if add_generation_prompt is defined and add_generation_prompt -%}
    {%- if ns.prev_message_type != 'tool_response' and ns.prev_message_type != 'tool_call' -%}
        {{- '<|turn>model\n' -}}
    {%- endif -%}

    {%- if not enable_thinking -%}
        {#- Suppress thinking — but not when awaiting tool responses -#}
        {%- if ns.prev_message_type != 'tool_call' -%}
            {{- '<|channel>thought\n<channel|>' -}}
        {%- endif -%}
    {%- endif -%}
{%- endif -%}