{{- bos_token -}}
{%- set preserve_thinking = preserve_thinking | default(false) -%}
{%- set enable_thinking = enable_thinking | default(true) -%}

{%- macro render_value(v) -%}
    {%- if v is string -%}
        {{- v -}}
    {%- elif v is boolean -%}
        {{- "true" if v else "false" -}}
    {%- elif v is none -%}
        {{- "null" -}}
    {%- elif v is mapping or (v is sequence and v is not string) -%}
        {{- v | tojson -}}
    {%- else -%}
        {{- v -}}
    {%- endif -%}
{%- endmacro -%}

{%- macro parse_content(content) -%}
    {%- if content is string -%}
        {{- content -}}
    {%- elif content is mapping and content.get("type") == "image" -%}
        {{- "<|vision_start|><|image|><|vision_end|>" -}}
    {%- elif content is mapping and content.get("type") == "video" -%}
        {{- "<|vision_start|><|video|><|vision_end|>" -}}
    {%- elif content is mapping and content.get("type") == "text" -%}
        {{- (content.get("text") or "") | string -}}
    {%- elif content is mapping -%}
        {{- content | tojson -}}
    {%- elif content is iterable -%}
        {%- set _ns = namespace(result="") -%}
        {%- for item in content -%}
            {%- if item is string -%}
                {%- set _ns.result = _ns.result + item -%}
            {%- elif item is mapping and item.get("type") == "image" -%}
                {%- set _ns.result = _ns.result + "<|vision_start|><|image|><|vision_end|>" -%}
            {%- elif item is mapping and item.get("type") == "video" -%}
                {%- set _ns.result = _ns.result + "<|vision_start|><|video|><|vision_end|>" -%}
            {%- elif item is mapping and item.get("type") == "text" -%}
                {%- set _ns.result = _ns.result + ((item.get("text") or "") | string) -%}
            {%- else -%}
                {%- set _ns.result = _ns.result + (item | tojson) -%}
            {%- endif -%}
        {%- endfor -%}
        {{- _ns.result -}}
    {%- endif -%}
{%- endmacro -%}

{%- macro render_tool_calls(tool_calls) -%}
    {%- for tool_call in tool_calls -%}
        {%- if not loop.first -%}{{- "\n\n" -}}{%- endif -%}
        {%- set func = tool_call["function"] if "function" in tool_call else tool_call -%}
        {%- set func_args = func.get("arguments") -%}
        {%- if func_args is string and (func_args | trim) not in ["", "{}", "null"] -%}
            {{- raise_exception("Tool call arguments must be a mapping, got a JSON-encoded string: parse arguments with json.loads() before applying the chat template") -}}
        {%- endif -%}
        {{- "<tool_call>\n<function=" + func["name"] + ">\n" -}}
        {%- if func_args is mapping -%}
            {%- for arg_name, arg_value in func_args.items() -%}
                {{- "<parameter=" + arg_name + ">\n" + render_value(arg_value) + "\n</parameter>\n" -}}
            {%- endfor -%}
        {%- endif -%}
        {{- "</function>\n</tool_call>" -}}
    {%- endfor -%}
{%- endmacro -%}

{%- macro tool_to_json(tool) -%}
    {%- set fn = tool.function if tool.function is defined else tool -%}
    {%- set ns_t = namespace(first=true) -%}
    {{- "{" -}}
    {%- for k, v in fn.items() -%}
        {%- if k != "defer_loading" -%}
            {%- if not ns_t.first -%}{{- ", " -}}{%- endif -%}
            {%- set ns_t.first = false -%}
            {{- k | tojson -}}{{- ": " -}}{{- v | tojson -}}
        {%- endif -%}
    {%- endfor -%}
    {{- "}" -}}
{%- endmacro -%}

{#- a tool_reference content part (vLLM, SGLang) names a tool from `tools`,
    usually a deferred one; it renders as that tool's definition -#}
{%- macro is_tool_reference(item) -%}
    {{- "1" if item is mapping and item.get("type") == "tool_reference" else "" -}}
{%- endmacro -%}

{%- macro referenced_tool_to_json(name) -%}
    {%- set _ns = namespace(found=none) -%}
    {%- for tool in tools or [] -%}
        {%- set fn = tool.function if tool.function is defined else tool -%}
        {%- if fn.name == name -%}
            {%- set _ns.found = fn -%}
        {%- endif -%}
    {%- endfor -%}
    {%- if _ns.found is none -%}
        {{- raise_exception("tool_reference names a tool that is not in tools: " + name | string) -}}
    {%- endif -%}
    {{- tool_to_json(_ns.found) -}}
{%- endmacro -%}

{%- macro render_tool_response(content) -%}
    {#- content that already carries the tag (pre-formatted by the caller) is
        passed through as-is instead of being wrapped a second time -#}
    {%- if content is string and "<tool_response>" in content -%}
        {{- content -}}
    {%- else -%}
    {{- "<tool_response>\n" -}}
    {%- if content is string -%}
        {{- content -}}
    {%- elif content is mapping -%}
        {{- parse_content(content) -}}
    {%- elif content is iterable -%}
        {%- for item in content -%}
            {%- if not loop.first -%}{{- "\n" -}}{%- endif -%}
            {%- if is_tool_reference(item) -%}
                {#- consecutive references share one <additional_tools> block -#}
                {%- if loop.first or not is_tool_reference(loop.previtem) -%}
                    {{- "<additional_tools>\n" -}}
                {%- endif -%}
                {{- referenced_tool_to_json(item.name) -}}
                {%- if loop.last or not is_tool_reference(loop.nextitem) -%}
                    {{- "\n</additional_tools>" -}}
                {%- endif -%}
            {%- elif item is mapping and item.result is defined and item.result is mapping and item.result.tools is defined -%}
                {{- "<additional_tools>\n" -}}
                {%- set _tl = item.result.tools -%}
                {%- if _tl is string -%}
                    {{- _tl -}}
                {%- elif _tl is mapping -%}
                    {{- tool_to_json(_tl) -}}
                {%- else -%}
                    {%- for t in _tl -%}
                        {%- if not loop.first -%}{{- "\n" -}}{%- endif -%}
                        {{- tool_to_json(t) -}}
                    {%- endfor -%}
                {%- endif -%}
                {{- "\n</additional_tools>" -}}
            {%- else -%}
                {{- parse_content(item) -}}
            {%- endif -%}
        {%- endfor -%}
    {%- endif -%}
    {{- "\n</tool_response>" -}}
    {%- endif -%}
{%- endmacro -%}

{%- set ns = namespace(system_prompt="", last_user_index=-1) -%}
{%- if messages and messages[0]["role"] == "system" -%}
    {%- if messages[0].get("content") -%}
        {%- set ns.system_prompt = parse_content(messages[0]["content"]) -%}
    {%- endif -%}
    {%- set messages = messages[1:] -%}
{%- endif -%}
{%- if tools -%}
    {%- set tools_ns = namespace(lines=[]) -%}
    {%- for tool in tools -%}
        {%- set fn = tool.function if tool.function is defined else tool -%}
        {%- set _dyn = (fn.defer_loading is defined and fn.defer_loading) or (tool.defer_loading is defined and tool.defer_loading) -%}
        {%- if not _dyn -%}
            {%- set tools_ns.lines = tools_ns.lines + [tool_to_json(fn)] -%}
        {%- endif -%}
    {%- endfor -%}
    {%- if tools_ns.lines -%}
        {%- set ns.system_prompt = ns.system_prompt + ("\n\n" if ns.system_prompt else "") + "<tools>\n" + (tools_ns.lines | join("\n")) + "\n</tools>" -%}
    {%- endif -%}
{%- endif -%}
{%- if ns.system_prompt -%}
    {{- "<|im_start|>system\n" + ns.system_prompt + "<|im_end|>\n" -}}
{%- endif -%}
{%- for message in messages -%}
    {%- if message["role"] == "user" -%}
        {%- set ns.last_user_index = loop.index0 -%}
    {%- endif -%}
{%- endfor -%}
{#- vLLM's and SGLang's Anthropic /v1/messages adapters split one tool_result that carries
    tool_reference blocks into consecutive tool messages with the same tool_call_id (text first,
    references second). Merge such runs into one tool turn so they render exactly like a single
    OpenAI-format tool message whose content holds the same items. -#}
{%- set carry = namespace(pending=[]) -%}
{%- for message in messages -%}
    {%- set _next = messages[loop.index0 + 1] if not loop.last else none -%}
    {%- set _merge = message.role == "tool" and not message.get("additional_tools")
        and _next is not none and _next.role == "tool" and not _next.get("additional_tools")
        and message.get("tool_call_id") and _next.get("tool_call_id") == message.get("tool_call_id") -%}
    {%- set _items = [] -%}
    {%- if message.role == "tool" and not message.get("additional_tools") -%}
        {%- set _c = message.get("content") -%}
        {%- if _c is string -%}
            {%- set _items = [{"type": "text", "text": _c}] if _c else [] -%}
        {%- elif _c is mapping -%}
            {%- set _items = [_c] -%}
        {%- elif _c -%}
            {%- set _items = _c | list -%}
        {%- endif -%}
    {%- endif -%}
    {%- if _merge -%}
        {%- set carry.pending = carry.pending + _items -%}
    {%- else -%}
    {{- "<|im_start|>" + message.role + "\n" -}}
    {%- if message.role == "assistant" -%}
        {%- generation -%}
        {%- set thinking = message.thinking if message.thinking is defined else message.reasoning if message.reasoning is defined else message.reasoning_content -%}
        {%- set keep_thinking = preserve_thinking or loop.index0 > ns.last_user_index -%}
        {%- if thinking is defined and keep_thinking -%}
            {{- "<think>" + (thinking or "") + "</think>" -}}
        {%- endif -%}
        {%- set _cfm_tag = "CONTINUE_FINAL_MESSAGE_TAG " -%}
        {%- set _has_cfm = false -%}
        {%- set content = "" -%}
        {%- if message.get("content") -%}
            {%- set content = parse_content(message.content) -%}
        {%- endif -%}
        {%- if not keep_thinking -%}
            {%- if "</think>" in content -%}
                {%- set content = content.split("</think>")[-1] | trim -%}
            {%- endif -%}
            {%- set content = "<think></think>" + content -%}
        {%- endif -%}
        {%- if content.endswith(_cfm_tag) -%}
            {%- set _has_cfm = true -%}
            {%- set _trunc_len = (content | length) - (_cfm_tag | length) -%}
            {%- set content = content[:_trunc_len] -%}
        {%- endif -%}
        {{- content -}}
        {%- if message.tool_calls -%}
            {{- render_tool_calls(message.tool_calls) -}}
        {%- endif -%}
        {%- if _has_cfm -%}
            {{- _cfm_tag -}}
        {%- endif -%}
        {{- "<|im_end|>\n" -}}
        {%- endgeneration -%}
    {%- elif message.role == "tool" -%}
        {%- if message.get("additional_tools") -%}
            {%- set _at = message["additional_tools"] -%}
            {#- definitions may live in additional_tools itself, or in content
                with additional_tools used as a plain truthy flag -#}
            {%- if _at is mapping or (_at is sequence and _at is not string) -%}
                {%- set _src = _at -%}
            {%- else -%}
                {%- set _src = message.get("content") -%}
            {%- endif -%}
            {#- nothing to reveal: skip the wrapper entirely rather than
                emitting an empty <additional_tools> block -#}
            {%- if _src is string and "<tool_response>" in _src -%}
                {{- _src -}}
            {%- elif _src is string and "<additional_tools>" in _src -%}
                {{- "<tool_response>\n" + _src + "\n</tool_response>" -}}
            {%- elif _src -%}
                {{- "<tool_response>\n<additional_tools>\n" -}}
                {%- if _src is string -%}
                    {{- _src -}}
                {%- elif _src is mapping -%}
                    {{- tool_to_json(_src) -}}
                {%- else -%}
                    {%- for t in _src -%}
                        {%- if not loop.first -%}{{- "\n" -}}{%- endif -%}
                        {{- tool_to_json(t) -}}
                    {%- endfor -%}
                {%- endif -%}
                {{- "\n</additional_tools>\n</tool_response>" -}}
            {%- endif -%}
        {%- elif carry.pending -%}
            {{- render_tool_response(carry.pending + _items) -}}
            {%- set carry.pending = [] -%}
        {%- else -%}
            {#- an empty or missing result still gets the wrapper, so every tool turn has the same shape -#}
            {{- render_tool_response(message.get("content") or "") -}}
        {%- endif -%}
        {{- "<|im_end|>\n" -}}
    {%- else %}
        {%- if message.get("content") -%}
            {{- parse_content(message["content"]) -}}
        {%- endif -%}
        {{- "<|im_end|>\n" -}}
    {%- endif %}
    {%- endif -%}
{%- endfor -%}
{%- if add_generation_prompt -%}
    {{- "<|im_start|>assistant\n" -}}
    {%- if enable_thinking -%}
        {{- "<think>" -}}
    {%- else -%}
        {{- "<think></think>" -}}
    {%- endif -%}
{%- endif -%}