{% macro render_extra_keys(json_dict, handled_keys) %}
    {%- if json_dict is mapping %}
        {%- for json_key in json_dict if json_key not in handled_keys %}
            {%- if json_dict[json_key] is mapping or (json_dict[json_key] is sequence and json_dict[json_key] is not string) %}
                {{- '\n<' ~ json_key ~ '>' ~ (json_dict[json_key] | tojson | safe) ~ '</' ~ json_key ~ '>' }}
            {%- else %}
                {{- '\n<' ~ json_key ~ '>' ~ (json_dict[json_key] | string) ~ '</' ~ json_key ~ '>' }}
            {%- endif %}
        {%- endfor %}
    {%- endif %}
{%- endmacro -%}
{%- set enable_thinking = enable_thinking if enable_thinking is defined else True %}
{%- set reasoning_budget = reasoning_budget if reasoning_budget is defined else None %}
{%- set truncate_history_thinking = truncate_history_thinking if truncate_history_thinking is defined else True %}

{#- Scan messages for VLM thinking toggles to override enable_thinking -#}
{%- set toggle = namespace(enable=enable_thinking) %}
{%- for m in messages %}
    {%- if m['role'] == 'user' or m['role'] == 'system' -%}
        {%- if m['content'] is string -%}
            {%- set c = m['content'] %}
            {%- if '/think' in c.replace('</think>', '') -%}
                {%- set toggle.enable = true -%}
            {%- elif '/no_think' in c -%}
                {%- set toggle.enable = false -%}
            {%- endif -%}
        {%- else -%}
            {%- for part in m['content'] -%}
                {%- if part['type'] == 'text' -%}
                    {%- set c = part['text'] %}
                    {%- if '/think' in c.replace('</think>', '') -%}
                        {%- set toggle.enable = true -%}
                    {%- elif '/no_think' in c -%}
                        {%- set toggle.enable = false -%}
                    {%- endif -%}
                {%- endif -%}
            {%- endfor -%}
        {%- endif -%}
    {%- endif -%}
{%- endfor -%}
{#- Prepare message iteration similar to LM template -#}
{%- set ns = namespace(last_user_idx = -1) %}
{%- set loop_messages = messages %}
{%- for m in loop_messages %}
    {%- if m["role"] == "user" %}
        {%- set ns.last_user_idx = loop.index0 %}
    {%- endif %}
{%- endfor -%}

{%- if messages[0]["role"] == "system" %}
    {%- set system_message = messages[0]["content"] %}
    {%- set loop_messages = messages[1:] %}
{%- else %}
    {%- set system_message = "" %}
    {%- set loop_messages = messages %}
{%- endif %}
{%- if not tools is defined %}
    {%- set tools = [] %}
{%- endif %}
{#- Recompute last_user_idx relative to loop_messages after handling system -#}
{%- set ns = namespace(last_user_idx = -1) %}
{%- for m in loop_messages %}
    {%- if m["role"] == "user" %}
        {%- set ns.last_user_idx = loop.index0 %}
    {%- endif %}
{%- endfor -%}
{#- System preamble with LM formatting, sanitize thinking toggles -#}
{%- if system_message is defined %}
    {%- set sys_content = system_message | string %}
    {%- set sys_content = sys_content.replace('</think>', '<_end_think>').replace('/think', '').replace('/no_think', '').replace('<_end_think>', '</think>') %}
    {{- "<|im_start|>system\n" + sys_content }}
{%- else %}
    {%- if tools is iterable and tools | length > 0 %}
        {{- "<|im_start|>system\n" }}
    {%- endif %}
{%- endif %}
{%- if tools is iterable and tools | length > 0 %}
    {%- if system_message is defined and system_message | length > 0 %}
        {{- "\n\n" }}
    {%- endif %}
    {{- "# Tools\n\nYou have access to the following functions:\n\n" }}
    {{- "<tools>" }}
    {%- for tool in tools %}
        {%- if tool.function is defined %}
            {%- set tool = tool.function %}
        {%- endif %}
        {{- "\n<function>\n<name>" ~ tool.name ~ "</name>" }}
        {%- if tool.description is defined %}
            {{- '\n<description>' ~ (tool.description | trim) ~ '</description>' }}
        {%- endif %}
        {{- '\n<parameters>' }}
        {%- if tool.parameters is defined and tool.parameters is mapping and tool.parameters.properties is defined and tool.parameters.properties is mapping %}
            {%- for param_name, param_fields in tool.parameters.properties|items %}
                {{- '\n<parameter>' }}
                {{- '\n<name>' ~ param_name ~ '</name>' }}
                {%- if param_fields.type is defined %}
                    {{- '\n<type>' ~ (param_fields.type | string) ~ '</type>' }}
                {%- endif %}
                {%- if param_fields.description is defined %}
                    {{- '\n<description>' ~ (param_fields.description | trim) ~ '</description>' }}
                {%- endif %}
                {%- if param_fields.enum is defined %}
                    {{- '\n<enum>' ~ (param_fields.enum | tojson | safe) ~ '</enum>' }}
                {%- endif %}
                {%- set handled_keys = ['name', 'type', 'description', 'enum'] %}
                {{- render_extra_keys(param_fields, handled_keys) }}
                {{- '\n</parameter>' }}
            {%- endfor %}
        {%- endif %}
        {%- set handled_keys = ['type', 'properties', 'required'] %}
        {{- render_extra_keys(tool.parameters, handled_keys) }}
        {%- if tool.parameters is defined and tool.parameters.required is defined %}
            {{- '\n<required>' ~ (tool.parameters.required | tojson | safe) ~ '</required>' }}
        {%- endif %}
        {{- '\n</parameters>' }}
        {%- set handled_keys = ['type', 'name', 'description', 'parameters'] %}
        {{- render_extra_keys(tool, handled_keys) }}
        {{- '\n</function>' }}
    {%- endfor %}
    {{- "\n</tools>" }}

    {{- '\n\nIf you choose to call a function ONLY reply in the following format with NO suffix:\n\n<tool_call>\n<function=example_function_name>\n<parameter=example_parameter_1>\nvalue_1\n</parameter>\n<parameter=example_parameter_2>\nThis is the value for the second parameter\nthat can span\nmultiple lines\n</parameter>\n</function>\n</tool_call>\n\n<IMPORTANT>\nReminder:\n- Function calls MUST follow the specified format: an inner <function=...></function> block must be nested within <tool_call></tool_call> XML tags\n- Required parameters MUST be specified\n- You may provide optional reasoning for your function call in natural language BEFORE the function call, but NOT after\n- If there is no function call available, answer the question like normal with your current knowledge and do not tell the user about function calls\n</IMPORTANT>' }}
{%- endif -%}
{%- if system_message is defined %}
    {{- '<|im_end|>\n' }}
{%- else %}
    {%- if tools is iterable and tools | length > 0 %}
        {{- '<|im_end|>\n' }}
    {%- endif %}
{%- endif -%}
{#- Iterate conversation -#}
{%- for message in loop_messages %}
    {%- if message.role == "assistant" %}
        {#- Use LM assistant handling -#}
        {%- if message.reasoning_content is defined and message.reasoning_content is string and message.reasoning_content | trim | length > 0 %}
            {%- set content = "<think>\n" ~ message.reasoning_content ~ "\n</think>\n" ~ (message.content | default('', true)) %}
        {%- else %}
            {%- set content = message.content | default('', true) %}
            {%- if content is string -%}
                {%- if '<think>' not in content and '</think>' not in content -%}
                    {%- set content = "<think></think>" ~ content -%}
                {%- endif -%}
            {%- else -%}
                {%- set content = content -%}
            {%- endif -%}
        {%- endif %}
        {%- if message.tool_calls is defined and message.tool_calls is iterable and message.tool_calls | length > 0 %}
            {{- '<|im_start|>assistant\n' }}
                {%- set include_content = not (truncate_history_thinking and loop.index0 < ns.last_user_idx) %}
                {%- if content is string and content | trim | length > 0 %}
                    {%- if include_content %}
                        {{- (content | trim) ~ '\n' -}}
                    {%- else %}
                        {%- set c = (content | string) %}
                        {%- if '</think>' in c %}
                            {%- set c = c.split('</think>')[-1] %}
                        {%- elif '<think>' in c %}
                            {%- set c = c.split('<think>')[0] %}
                        {%- endif %}
                        {%- set c = "<think></think>" ~ c | trim %}
                        {%- if c | length > 0 %}
                            {{- c ~ '\n' -}}
                        {%- endif %}
                    {%- endif %}
                {%- else %}
                    {{- "<think></think>" -}}
                {%- endif %}
                {%- for tool_call in message.tool_calls %}
                    {%- if tool_call.function is defined %}
                        {%- set tool_call = tool_call.function %}
                    {%- endif %}
                    {{- '<tool_call>\n<function=' ~ tool_call.name ~ '>\n' -}}
                        {%- if tool_call.arguments is defined %}
                            {%- for args_name, args_value in tool_call.arguments|items %}
                                {{- '<parameter=' ~ args_name ~ '>\n' -}}
                                    {%- set args_value = args_value | tojson | safe if args_value is mapping or (args_value is sequence and args_value is not string) else args_value | string %}
                                {{- args_value ~ '\n</parameter>\n' -}}
                            {%- endfor %}
                        {%- endif %}
                    {{- '</function>\n</tool_call>\n' -}}
                {%- endfor %}
                {{- '<|im_end|>\n' }}
        {%- else %}
            {%- if not (truncate_history_thinking and loop.index0 < ns.last_user_idx) %}
                {{- '<|im_start|>assistant\n' ~ (content | default('', true) | string | trim) ~ '<|im_end|>\n' }}
            {%- else %}
                {%- set c = (content | default('', true) | string) %}
                {%- if '<think>' in c and '</think>' in c %}
                    {%- set c = "<think></think>" ~ c.split('</think>')[-1] %}
                {%- endif %}
                {%- set c = c | trim %}
                {%- if c | length > 0 %}
                    {{- '<|im_start|>assistant\n' ~ c ~ '<|im_end|>\n' }}
                {%- else %}
                    {{- '<|im_start|>assistant\n<|im_end|>\n' }}
                {%- endif %}
            {%- endif %}
        {%- endif %}
    {%- elif message.role == "user" or message.role == "system" %}
        {{- '<|im_start|>' + message.role + '\n' }}
        {#- Build VLM multimodal content when content is a sequence -#}
        {%- if message.content is string -%}
            {%- set content = (message.content | string) %}
        {%- else -%}
            {%- set text_ns = namespace(val='') -%}
            {%- set mm_content = '' -%}
            {%- set counters = namespace(images=0, videos=0, audios=0) -%}
            {%- for part in message['content'] -%}
                {%- if part['type'] == 'image' or part['type'] == 'image_url' -%}
                    {%- set counters.images = counters.images + 1 -%}
                {%- elif part['type'] == 'video' or part['type'] == 'video_url' -%}
                    {%- set counters.videos = counters.videos + 1 -%}
                {%- elif part['type'] == 'audio' or part['type'] == 'audio_url' -%}
                    {%- set counters.audios = counters.audios + 1 -%}
                {%- elif part['type'] == 'text' -%}
                    {%- set text_ns.val = text_ns.val + part['text'] -%}
                {%- endif -%}
            {%- endfor -%}
            {%- if '<image>' in text_ns.val -%}
                {%- set counters.images = 0 -%}
            {%- endif -%}
            {%- if '<video>' in text_ns.val -%}
                {%- set counters.videos = 0 -%}
            {%- endif -%}
            {%- if '<so_embedding>' in text_ns.val -%}
                {%- set counters.audios = 0 -%}
            {%- endif -%}
            {%- if counters.images > 1 -%}
                {%- set image_tags = namespace(tags=[]) -%}
                {%- for i in range(counters.images) -%}
                    {%- set image_tags.tags = image_tags.tags + ['<image ' + (i + 1)|string + '><image>'] -%}
                {%- endfor -%}
                {%- set mm_content = ' '.join(image_tags.tags) + '\n' -%}
            {%- elif counters.images == 1 -%}
                {%- set mm_content = '<image>\n' -%}
            {%- endif -%}
            {%- set mm_content = mm_content + '<video>\n' * counters.videos -%}
            {%- set mm_content = mm_content + '<so_embedding>\n' * counters.audios -%}
            {%- set content = mm_content + text_ns.val.lstrip('\n') -%}
        {%- endif -%}
        {#- Sanitize thinking toggle directives from user/system content -#}
        {%- set content = content.replace('</think>', '<_end_think>').replace('/think', '').replace('/no_think', '').replace('<_end_think>', '</think>') -%}
        {%- set content = content | trim -%}
        {%- if message.role == "user" and loop.index0 == ns.last_user_idx and reasoning_budget is not none -%}
            {{- content + '\n\n{thinking token budget: ' + (reasoning_budget | string) + '}' -}}
        {%- else -%}
            {{- content -}}
        {%- endif -%}
        {{- '<|im_end|>\n' }}
    {%- elif message.role == "tool" %}
        {%- if loop.previtem and loop.previtem.role != "tool" %}
            {{- '<|im_start|>user\n' }}
        {%- endif %}
        {{- '<tool_response>\n' }}
        {{- message.content }}
        {{- '\n</tool_response>\n' }}
        {%- if not loop.last and loop.nextitem.role != "tool" %}
            {{- '<|im_end|>\n' }}
        {%- elif loop.last %}
            {{- '<|im_end|>\n' }}
        {%- endif %}
    {%- else %}
        {{- '<|im_start|>' + message.role + '\n' + message.content + '<|im_end|>\n' }}
    {%- endif %}
{%- endfor -%}
{#- Generation prompt using computed thinking toggle -#}
{%- if add_generation_prompt %}
    {%- if toggle.enable %}
        {{- '<|im_start|>assistant\n<think>\n' }}
    {%- else %}
        {{- '<|im_start|>assistant\n<think></think>' }}
    {%- endif %}
{%- endif %}