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// SPDX-License-Identifier: MIT OR Apache-2.0
#![allow(unused_imports, dead_code)]
//! 2026-09-26: Argument-fragment streaming for the tool-call detector:
//! newly completed `<parameter>` values, Gemma-4 arguments and JSON argument
//! bytes become `ToolCallArgsFragment`s; also bare `<function…>` blocks.
//! `process` (streaming_impl.rs) and `flush` (streaming_flush.rs) call these.
//!
//! Owner: server (tool parsing).
//! Invariants:
//! - `stream_ready_fragments` never moves `current_tc_emitted` backwards.
use super::*;
impl StreamingToolDetector {
/// 2026-09-26: Normalize one `<parameter=KEY>VALUE</parameter>` pair for a
/// fragment: the key through `salvage_echoed_param` and
/// `normalize_param_name`, the value through `coerce_all` against the
/// call's schema. Returns `(key, JSON value)`; when coercion yields
/// nothing, the value is the raw string, JSON-quoted.
pub(super) fn coerce_kv(&self, raw_key: &str, raw_value: &str) -> (String, String) {
let name = self.current_tc_name.clone().unwrap_or_default();
// 2026-09-26: Re-split `parameter=filePath>…`, where the real key
// leaked into the value, with the helper `backfill_required_params`
// also uses (validation.rs). A recovered key that was already
// streamed is not used, so no key appears twice.
let salvaged =
crate::tool_parser::salvage_echoed_param(&self.tools, &name, raw_key, raw_value)
.filter(|(real_key, _)| !self.emitted_keys.contains(real_key));
let (raw_key, raw_value) = match &salvaged {
Some((real_key, real_val)) => (real_key.as_str(), real_val.as_str()),
None => (raw_key, raw_value),
};
let norm_key = crate::tool_parser::normalize_param_name(&self.tools, &name, raw_key);
let fallback = || serde_json::to_string(raw_value).unwrap_or_else(|_| "\"\"".to_string());
let single = serde_json::to_string(&serde_json::json!({ norm_key.clone(): raw_value }));
let Ok(single_args) = single else {
return (norm_key, fallback());
};
let mut tc = ToolCall {
id: String::new(),
call_type: "function".into(),
function: FunctionCall {
name,
arguments: single_args,
},
};
coerce_all(std::slice::from_mut(&mut tc), &self.tools);
let json_value_string = serde_json::from_str::<serde_json::Value>(&tc.function.arguments)
.ok()
.and_then(|v| v.get(&norm_key).cloned())
.and_then(|v| serde_json::to_string(&v).ok())
.unwrap_or_else(fallback);
(norm_key, json_value_string)
}
/// 2026-09-26: Emit the argument fragments of the open call that are newly
/// complete in `self.buffer[..limit]`, advancing `current_tc_emitted`
/// past them. Every caller skips it when `buffer_args` is set.
///
/// - XML (`<parameter=K>V</parameter>`): each complete parameter becomes a
/// coerced `"key":value` fragment with a leading `{` or `,`. On
/// `final_close`, missing required string parameters are added as `""`
/// and the closing `}` is emitted.
/// - Gemma-4 (`call:NAME{`): the body up to the first `}`, converted by
/// `gemma4_to_json`; `final_close` adds the closing `}`.
/// - JSON (`"arguments": {...}`): the model's bytes, forwarded without
/// coercion, up to the object's balanced end.
pub(super) fn stream_ready_fragments(
&mut self,
limit: usize,
final_close: bool,
) -> Vec<DetectorOutput> {
let mut outputs = Vec::new();
let idx = self.call_counter as usize;
let scan = &self.buffer[..limit.min(self.buffer.len())];
if scan.contains("<parameter=") {
loop {
let from = self.current_tc_emitted;
let Some(rel_open) = self.buffer[from..limit].find("<parameter=") else {
break;
};
let open_at = from + rel_open;
let key_region = open_at + "<parameter=".len();
let Some(rel_gt) = self.buffer[key_region..limit].find('>') else {
break;
};
let gt_at = key_region + rel_gt;
let value_region = gt_at + 1;
// 2026-09-26: A close missing its `>` right before the next
// opener (`</parameter<parameter=KEY>`) also ends the value;
// scanning resumes at that `<parameter=`.
let exact = self.buffer[value_region..limit].find("</parameter>");
let garbled = self.buffer[value_region..limit].find("</parameter<parameter=");
let (rel_close, advance) = match (exact, garbled) {
(Some(e), Some(g)) if g < e => (g, "</parameter".len()),
(Some(e), _) => (e, "</parameter>".len()),
(None, Some(g)) => (g, "</parameter".len()),
(None, None) => break,
};
let close_at = value_region + rel_close;
// 2026-09-26: Key and value are trimmed, as in
// `parse_qwen3_coder_call`.
let key = self.buffer[key_region..gt_at].trim().to_string();
let raw_value = self.buffer[value_region..close_at].trim();
let (norm_key, json_value_string) = self.coerce_kv(&key, raw_value);
let prefix = if !self.args_open {
self.args_open = true;
"{"
} else {
","
};
let quoted_key =
serde_json::to_string(&norm_key).unwrap_or_else(|_| "\"\"".to_string());
let fragment = format!("{prefix}{quoted_key}:{json_value_string}");
outputs.push(DetectorOutput::ToolCallArgsFragment { fragment, idx });
self.incremental_emitted = true;
self.emitted_keys.push(norm_key);
self.current_tc_emitted = close_at + advance;
}
if final_close {
// 2026-09-26: Required parameters the model never wrote are
// added as `""` when their schema type is `string` or absent,
// as `backfill_required_params` does (`validation/backfill.rs`).
if let Some(name) = self.current_tc_name.clone()
&& let Some(tool_def) = self.tools.iter().find(|t| t.function.name == name)
&& let Some(params) = tool_def.function.parameters.as_ref()
{
let properties = params.get("properties").and_then(|p| p.as_object());
let required: Vec<String> = params
.get("required")
.and_then(|r| r.as_array())
.map(|a| {
a.iter()
.filter_map(|v| v.as_str().map(String::from))
.collect()
})
.unwrap_or_default();
for req in &required {
if self.emitted_keys.iter().any(|k| k == req) {
continue;
}
let is_string = properties
.and_then(|p| p.get(req))
.and_then(|v| v.get("type"))
.and_then(|t| t.as_str())
.is_none_or(|t| t == "string");
if !is_string {
continue;
}
let prefix = if !self.args_open {
self.args_open = true;
"{"
} else {
","
};
let quoted_key =
serde_json::to_string(req).unwrap_or_else(|_| "\"\"".to_string());
outputs.push(DetectorOutput::ToolCallArgsFragment {
fragment: format!("{prefix}{quoted_key}:\"\""),
idx,
});
self.incremental_emitted = true;
self.emitted_keys.push(req.clone());
}
}
let closing = if !self.args_open {
self.args_open = true;
"{}".to_string()
} else {
"}".to_string()
};
outputs.push(DetectorOutput::ToolCallArgsFragment {
fragment: closing,
idx,
});
self.incremental_emitted = true;
}
} else if scan.contains("call:") {
let args_start = super::streaming::find_args_start(&self.buffer);
if args_start >= limit {
return outputs;
}
let body = &self.buffer[args_start..limit];
let settled = if let Some(e) = body.find('}') {
e
} else {
let mut s = body.len();
while s > 0 && !body.is_char_boundary(s) {
s -= 1;
}
s
};
let accumulated_raw = &body[..settled];
let converted_json = gemma4_to_json(&format!("gemma4{{{}}}", accumulated_raw));
if converted_json.len() > 2 {
let json_args_body = &converted_json[1..converted_json.len() - 1];
let already = self.current_tc_emitted;
if json_args_body.len() > already {
let new_frag = &json_args_body[already..];
let prefix = if !self.args_open {
self.args_open = true;
"{"
} else {
""
};
outputs.push(DetectorOutput::ToolCallArgsFragment {
fragment: format!("{}{}", prefix, new_frag),
idx,
});
self.current_tc_emitted = json_args_body.len();
self.incremental_emitted = true;
}
}
if final_close {
let closing = if !self.args_open {
self.args_open = true;
"{}".to_string()
} else {
"}".to_string()
};
outputs.push(DetectorOutput::ToolCallArgsFragment {
fragment: closing,
idx,
});
self.incremental_emitted = true;
}
} else if scan.contains("\"arguments\"") {
let args_start = super::streaming::find_args_start(&self.buffer);
if args_start >= limit {
return outputs;
}
// 2026-09-26: Start at the object's `{`: `find_balanced_json_end`
// needs a leading `{`, so whitespace after the colon is skipped.
let mut args_start = args_start;
while args_start < limit && self.buffer.as_bytes()[args_start].is_ascii_whitespace() {
args_start += 1;
}
let body = &self.buffer[args_start..limit];
let settled = if let Some(e) = find_balanced_json_end(body) {
e
} else {
// 2026-09-26: No balanced close yet: stream up to a char
// boundary.
let mut s = body.len();
while s > 0 && !body.is_char_boundary(s) {
s -= 1;
}
s
};
let already = self.current_tc_emitted.min(settled);
let new = &body[already..settled];
if !new.is_empty() {
outputs.push(DetectorOutput::ToolCallArgsFragment {
fragment: new.to_string(),
idx,
});
self.current_tc_emitted = settled;
self.incremental_emitted = true;
}
}
outputs
}
}
impl StreamingToolDetector {
/// 2026-09-26: Handle a bare `<function…>` block (no `<tool_call>`
/// wrapper). While the block is open, its header and each completed
/// parameter stream as for a `<tool_call>` block.
///
/// Returns `true` when the caller's scan loop should `continue` (a
/// complete block was consumed), `false` when it should `break` and wait
/// for more tokens.
pub(super) fn process_bare_function(&mut self, outputs: &mut Vec<DetectorOutput>) -> bool {
let Some(func_pos) = self.buffer.find("<function") else {
return false;
};
if func_pos > 0 {
let before = self.buffer[..func_pos].to_string();
self.buffer = self.buffer[func_pos..].to_string();
outputs.push(DetectorOutput::Content(before));
}
if let Some(end) = bare_function_end(&self.buffer) {
// 2026-09-26: A call whose fragments already streamed (below) is
// closed as the `<tool_call>` arm closes one: remaining fragments
// and `ToolCallEnd`. A whole `ToolCall` here would deliver it
// twice, so the two branches must stay exclusive.
if !self.buffer_args && self.incremental_emitted {
let idx = self.call_counter as usize;
let frags = self.stream_ready_fragments(end, true);
outputs.extend(frags);
outputs.push(DetectorOutput::ToolCallEnd { idx });
self.call_counter += 1;
self.emitted_tool_calls = true;
self.buffer = self.buffer[end..].to_string();
self.reset_call_state();
return true;
}
let block = self.buffer[..end].to_string();
self.buffer = self.buffer[end..].to_string();
let (_, calls) = parse_bare_function_calls(&block);
for tc in calls {
let idx = self.call_counter as usize;
self.call_counter += 1;
self.emitted_tool_calls = true;
outputs.push(DetectorOutput::ToolCall(tc, idx));
}
self.reset_call_state();
return true;
}
// 2026-09-26: Block not closed yet: emit the header once the name is
// known, then any newly completed parameters. `stream_ready_fragments`
// looks only for `<parameter=`, so the `<function=NAME>` still in the
// buffer is skipped.
if self.current_tc_name.is_none()
&& let Some(name) = extract_streaming_name(&self.buffer)
{
let id = next_tool_call_id();
let idx = self.call_counter as usize;
outputs.push(DetectorOutput::ToolCallStart {
id: id.clone(),
name: name.clone(),
idx,
});
self.current_tc_name = Some(name);
self.current_tc_id = Some(id);
}
if !self.buffer_args && self.current_tc_name.is_some() {
let frags = self.stream_ready_fragments(self.buffer.len(), false);
outputs.extend(frags);
}
false
}
}