"""Human Voice Rewrite Demo backend (PRD v1.1). Serves the static demo page and domain endpoints that run the real OpenRouter pipeline. Run via ./local_start.sh. """ from __future__ import annotations from pathlib import Path from typing import Any, Callable from fastapi import FastAPI, HTTPException from fastapi.responses import FileResponse from evidence import sanitize_diagnosis from llm import LLMError, LlmClient from prompts import ( build_analyze_prompt, build_diagnose_prompt, build_recheck_prompt, build_reference_prompt, build_scaffold_prompt, normalize_diagnose_payload, ) from schemas import ( AnalyzeRequest, AnalyzeResponse, DiagnoseRequest, DiagnoseResponse, GlobalChecks, RecheckRequest, RecheckResponse, ReferenceRequest, ReferenceResponse, RevisionTarget, ScaffoldRequest, ScaffoldResponse, ) app = FastAPI(title="Human Voice Rewrite Demo", version="1.1.0") client: LlmClient | None = None HERE = Path(__file__).resolve().parent def get_client() -> LlmClient: global client if client is None: client = LlmClient() return client def run_json(phase: str, system: str, user: str, check: Callable[[dict[str, Any]], str | None] | None = None) -> dict: try: return get_client().complete_json(system, user, validate=check) except LLMError as exc: raise HTTPException(status_code=502, detail=f"{phase}失败：{exc}") from exc def _count_check(expected: int, key: str) -> Callable[[dict[str, Any]], str | None]: """返回语义校验器：LLM 输出里按段组织的数组条目数必须与输入段数一致。 不一致时返回一行中文说明（触发 complete_json 重试一次；两次都失败才变 502 单行错误）——真因：真实 LLM 偶发返回合法 JSON 但段落条目不全， 此前无数量校验被静默接受，AI 初审出现"4 段标题只显示 1 段"（用户实测）。""" def check(data: dict[str, Any]) -> str | None: got = len(data.get(key) or []) if got != expected: return f"结果段落数与输入不一致（输入 {expected} 段，返回 {got} 段）" return None return check def _friendly_validation(exc: Exception) -> str: """把 pydantic ValidationError 压缩成一行用户可读摘要（PRD §11 失败兜底： 返回用户可读错误，不把完整校验堆栈甩给页面）。""" errs = getattr(exc, "errors", lambda: [])() if not errs: return f"结果格式不符合预期：{exc}" parts = [] for e in errs[:2]: loc = " → ".join(str(x) for x in e.get("loc", [])) parts.append(f"{loc}：{e.get('msg', '')}" if loc else e.get("msg", "")) more = f"（共 {len(errs)} 处）" if len(errs) > 2 else "" return "结果格式不符合预期：" + "；".join(parts) + more @app.get("/api/health") def health() -> dict: return {"status": "ok"} @app.post("/api/analyze", response_model=AnalyzeResponse) def analyze(req: AnalyzeRequest) -> AnalyzeResponse: if not any(p.strip() for p in req.paragraphs): raise HTTPException(status_code=422, detail="文本为空，无法开始分析") system, user = build_analyze_prompt(req.prompt, req.word_limit, req.paragraphs, req.constraints) data = run_json("分析", system, user, check=_count_check(len(req.paragraphs), "paragraphs")) try: return AnalyzeResponse.model_validate(data) except Exception as exc: # pydantic ValidationError etc. raise HTTPException(status_code=502, detail=f"分析{_friendly_validation(exc)}") from exc @app.post("/api/diagnose", response_model=DiagnoseResponse) def diagnose(req: DiagnoseRequest) -> DiagnoseResponse: system, user = build_diagnose_prompt( req.prompt, req.word_limit, req.paragraphs, req.confirmed_anchors, req.global_constraints, req.paragraph_constraints, req.initial_analysis, ) data = run_json("诊断", system, user, check=_count_check(len(req.paragraphs), "paragraph_briefs")) data = normalize_diagnose_payload(data) try: resp = DiagnoseResponse.model_validate(data) except Exception as exc: raise HTTPException(status_code=502, detail=f"诊断{_friendly_validation(exc)}") from exc return sanitize_diagnosis(resp, req.paragraphs) @app.post("/api/recheck", response_model=RecheckResponse) def recheck(req: RecheckRequest) -> RecheckResponse: if len(req.original_paragraphs) != len(req.rewrite_paragraphs): raise HTTPException(status_code=422, detail="原文段数与改写段数不一致") if any(not p.strip() for p in req.rewrite_paragraphs): raise HTTPException(status_code=422, detail="存在空段：全部段落完成改写后才能提交复检") system, user = build_recheck_prompt(req) data = run_json("复检", system, user) if isinstance(data.get("status"), str): data["status"] = "pass" if data["status"] == "pass" else "revision_required" if not data.get("checked_rewrite_version"): data["checked_rewrite_version"] = req.rewrite_version or "" try: resp = RecheckResponse.model_validate(data) except Exception as exc: raise HTTPException(status_code=502, detail=f"复检{_friendly_validation(exc)}") from exc if resp.status == "revision_required" and not resp.revision_targets: resp = RecheckResponse( status="revision_required", checked_rewrite_version=resp.checked_rewrite_version or req.rewrite_version, global_checks=resp.global_checks or GlobalChecks(), revision_targets=[ RevisionTarget( paragraph_id="p1", blocking_issue="模型判定需要返工但未指明段落", single_revision_goal="重读当前段改写并修正最明显的问题", ) ], ) return resp @app.post("/api/scaffold", response_model=ScaffoldResponse) def scaffold(req: ScaffoldRequest) -> ScaffoldResponse: system, user = build_scaffold_prompt( req.paragraph_id, req.original_text, req.semantic_anchor, req.rewrite_goal, req.global_constraints, req.paragraph_constraints, ) data = run_json("写作起点", system, user) try: resp = ScaffoldResponse.model_validate(data) except Exception as exc: raise HTTPException(status_code=502, detail=f"写作起点{_friendly_validation(exc)}") from exc resp.paragraph_id = resp.paragraph_id or req.paragraph_id return resp @app.post("/api/reference", response_model=ReferenceResponse) def reference(req: ReferenceRequest) -> ReferenceResponse: goal = req.rewrite_goal or req.primary_goal system, user = build_reference_prompt( req.paragraph_id, req.original_text, req.semantic_anchor, goal, req.global_constraints, req.paragraph_constraints, ) data = run_json("参考片段", system, user) try: resp = ReferenceResponse.model_validate(data) except Exception as exc: raise HTTPException(status_code=502, detail=f"参考片段{_friendly_validation(exc)}") from exc snippet = resp.reference_snippet or resp.starter resp.paragraph_id = resp.paragraph_id or req.paragraph_id resp.starter = snippet resp.reference_snippet = snippet return resp @app.get("/") def index() -> FileResponse: return FileResponse(HERE / "index.html", media_type="text/html")