#!/usr/bin/env python3
"""Manual SSE parser (no SDK): accumulates text, tool input JSON and thinking; handles ping/error/unknown events.

STATUS: LIVE_VERIFIED 2026-09-18 (stdlib urllib via scripts/live.py). Run: .venv/bin/python examples/anthropic/streaming/manual_sse_parser.py
"""
import json
import sys
from pathlib import Path

sys.path.insert(0, str(Path(__file__).resolve().parents[3]))
from scripts.live import anthropic_request  # noqa: E402


def parse_sse(lines):
    """Yield (event_name, data_dict). SSE frames are separated by blank lines; we only use event:/data: fields."""
    name, data = None, []
    for line in lines:
        if line == "":
            if data:
                yield name, json.loads("\n".join(data))
            name, data = None, []
        elif line.startswith("event:"):
            name = line[6:].strip()
        elif line.startswith("data:"):
            data.append(line[5:].strip())
    if data:
        yield name, json.loads("\n".join(data))


body = {"model": "claude-haiku-4-5-20251001", "max_tokens": 64, "stream": True,
        "tools": [{"name": "get_weather", "description": "Weather for a city", "input_schema": {"type": "object", "properties": {"city": {"type": "string"}}, "required": ["city"]}}],
        "tool_choice": {"type": "tool", "name": "get_weather"}, "messages": [{"role": "user", "content": "Weather in Paris?"}]}
status, lines, headers = anthropic_request("POST", "/v1/messages", body, stream=True, est_cost_usd=0.0009, note="example manual_sse_parser.py")
assert status == 200, status
blocks: dict[int, dict] = {}
message, order = {}, []
for name, data in parse_sse(lines):
    order.append(name)
    t = data.get("type")
    if t == "message_start":
        message = data["message"]
    elif t == "content_block_start":
        b = dict(data["content_block"]); b["_json"] = ""; blocks[data["index"]] = b
    elif t == "content_block_delta":
        d, b = data["delta"], blocks[data["index"]]
        if d["type"] == "text_delta": b["text"] += d["text"]
        elif d["type"] == "input_json_delta": b["_json"] += d["partial_json"]
        elif d["type"] == "thinking_delta": b["thinking"] += d["thinking"]
        elif d["type"] == "signature_delta": b["signature"] = d["signature"]
        elif d["type"] == "citations_delta": b.setdefault("citations", []).append(d["citation"])
    elif t == "content_block_stop":
        b = blocks[data["index"]]
        if b["type"] in ("tool_use", "server_tool_use"):
            b["input"] = json.loads(b.pop("_json") or "{}")   # guard the parse when using eager_input_streaming
        else:
            b.pop("_json", None)
    elif t == "message_delta":
        message.update({k: v for k, v in data["delta"].items()}); message["usage"].update(data["usage"])  # usage is cumulative
    elif t == "ping":
        pass
    elif t == "error":
        raise RuntimeError(data["error"])        # e.g. overloaded_error mid-stream
    elif t == "message_stop":
        break
    else:
        pass                                      # unknown event types must be ignored (versioning policy)
message["content"] = [blocks[i] for i in sorted(blocks)]
print("order :", " ".join(order))
print("stop  :", message["stop_reason"], "| usage:", message["usage"])
print("blocks:", json.dumps(message["content"])[:200])