// src/api/papers.rs
use axum::{
    extract::{Query, State},
    http::StatusCode,
    Json,
};
use serde::{Deserialize, Serialize};
use sqlx::Row;
use std::sync::Arc;
use tokio::fs;
use tracing::{error, info, warn};

use super::error::{ApiResult, AppError};
use super::helpers::{
    check_paper_paths_in_db, convert_ads_doc_to_standard, get_paper_from_db, parse_paper_row,
    save_paper_to_db, SQLITE_PARAM_LIMIT,
};
use super::{AppState, StandardPaper};

// 检索请求参数
#[derive(Debug, Deserialize)]
pub struct SearchParams {
    pub q: String,
    pub source: Option<String>, // "all" | "ads" | "arxiv"
    pub rows: Option<i32>,
    pub start: Option<i32>,   // 分页起始偏移量
    pub sort: Option<String>, // 排序字段
}

// ── GET /api/search ──
// 统一检索接口，合并去重 ADS 和 arXiv 数据
pub async fn search_papers(
    State(state): State<Arc<AppState>>,
    Query(params): Query<SearchParams>,
) -> ApiResult<Json<Vec<StandardPaper>>> {
    let source = params.source.unwrap_or_else(|| "all".to_string());
    let rows = params.rows.unwrap_or(10);
    let start = params.start.unwrap_or(0);
    let sort = params.sort.as_deref().unwrap_or("relevance");

    let results =
        crate::services::search::search_papers(&state, &params.q, &source, start, rows, sort)
            .await
            .map_err(|e| AppError::internal(e.to_string()))?;

    Ok(Json(results))
}

// ── POST /api/download ──
#[derive(Deserialize)]
pub struct DownloadRequest {
    pub bibcode: String,
    pub force: Option<bool>, // 强制重新下载，即使已存在本地文件
}

// 一键双格式并行下载文献 (PDF + HTML)，支持 force=true 强制重新下载
pub async fn download_paper(
    State(state): State<Arc<AppState>>,
    Json(req): Json<DownloadRequest>,
) -> ApiResult<Json<StandardPaper>> {
    let force = req.force.unwrap_or(false);
    info!(
        "接收到文献下载指令，标识符: {}, 强制重下: {}",
        req.bibcode, force
    );

    let paper = state
        .downloader
        .download_paper_service(&state.db, &state.config.library_dir, &req.bibcode, force)
        .await
        .map_err(|e| AppError::internal(e.to_string()))?;

    Ok(Json(paper))
}

// ── POST /api/parse ──
#[derive(Deserialize)]
pub struct ParseRequest {
    pub bibcode: String,
    pub force: Option<bool>,
}

#[derive(Serialize)]
pub struct ParseResponse {
    pub markdown: String,
}

// 将 HTML / PDF 转换为标准英文 Markdown 文本（HTML 优先，PDF 调用 MinerU 远程 API 且上传七牛云）
pub async fn parse_paper(
    State(state): State<Arc<AppState>>,
    Json(req): Json<ParseRequest>,
) -> ApiResult<Json<ParseResponse>> {
    info!(
        "接收到文献结构化解析指令: {} (强制重新解析: {:?})",
        req.bibcode, req.force
    );

    let force = req.force.unwrap_or(false);
    let markdown = crate::services::parser::parse_paper_service(
        &state.db,
        &state.config.library_dir,
        &state.qiniu,
        &state.config,
        &req.bibcode,
        force,
    )
    .await
    .map_err(|e| {
        // 根据错误信息推断合适的错误类型（保留原有状态码语义）
        let msg = e.to_string();
        if msg.contains("未注册")
            || msg.contains("未找到")
            || msg.contains("丢失")
            || msg.contains("未在数据库中注册")
        {
            AppError::not_found(msg)
        } else if msg.contains("请先下载") {
            AppError::bad_request(msg)
        } else {
            AppError::internal(msg)
        }
    })?;

    Ok(Json(ParseResponse { markdown }))
}

// ── POST /api/translate ──
#[derive(Deserialize)]
pub struct TranslateRequest {
    pub bibcode: String,
    pub force: Option<bool>,
}

#[derive(Serialize)]
pub struct TranslateResponse {
    pub translation: String,
}

// 文献中英双栏对比翻译接口（包含词表注入与本地物理缓存）
pub async fn translate_paper(
    State(state): State<Arc<AppState>>,
    Json(req): Json<TranslateRequest>,
) -> ApiResult<Json<TranslateResponse>> {
    let force = req.force.unwrap_or(false);
    info!(
        "接收到对比翻译请求: 文献={}, 强制重译={}",
        req.bibcode, force
    );

    let (_, _, md_opt, tr_opt) =
        check_paper_paths_in_db(&state.db, &state.config.library_dir, &req.bibcode)
            .await
            .map_err(|e| AppError::not_found(format!("查询文献路径失败: {}", e)))?
            .ok_or_else(|| AppError::not_found("该文献未注册在数据库中"))?;

    // 若本地已存在翻译物理文件且未指明强制重译，直读本地缓存返回
    if !force {
        if let Some(tr_rel) = tr_opt {
            let tr_abs = state.config.library_dir.join(&tr_rel);
            if tr_abs.exists() {
                if let Ok(content) = fs::read_to_string(&tr_abs).await {
                    return Ok(Json(TranslateResponse {
                        translation: content,
                    }));
                }
            }
        }
    }

    // 检查英文解析文件是否存在
    let md_rel = match md_opt {
        Some(rel) => rel,
        None => {
            error!(
                "文献 {} 翻译失败：文献未完成解析，缺少英文 Markdown 路径",
                req.bibcode
            );
            return Err(AppError::bad_request("文献必须先完成解析方可翻译"));
        }
    };
    let md_abs = state.config.library_dir.join(&md_rel);
    if !md_abs.exists() {
        error!(
            "文献 {} 翻译失败：解析的英文 Markdown 文件 {:?} 不存在",
            req.bibcode, md_abs
        );
        return Err(AppError::bad_request("解析 Markdown 文件丢失"));
    }

    let english_markdown = fs::read_to_string(&md_abs).await.map_err(|e| {
        error!("文献 {} 翻译失败：读取解析内容失败: {}", req.bibcode, e);
        AppError::internal(format!("读取解析内容失败: {}", e))
    })?;

    // 调用 LLM 翻译服务并注入对照词表
    let translated_markdown = crate::services::translation::translate_markdown(
        &english_markdown,
        &state.dict,
        &state.medium_llm,
    )
    .await
    .map_err(|e| {
        error!(
            "文献 {} 翻译失败：调用 LLM 翻译发生错误: {}",
            req.bibcode, e
        );
        AppError::internal(format!("调用 LLM 翻译失败: {}", e))
    })?;

    // 翻译结果持久化（C2：抽取为共享函数，与批量任务复用）
    crate::services::translation::persist_translation(
        &state.db,
        &state.config.library_dir,
        &req.bibcode,
        &translated_markdown,
    )
    .await
    .map_err(|e| AppError::internal(format!("翻译结果持久化失败: {}", e)))?;

    Ok(Json(TranslateResponse {
        translation: translated_markdown,
    }))
}

#[derive(Debug, Serialize)]
pub struct CitationsResponse {
    pub bibcode: String,
    pub title: String,
    pub citation_count: i32,
    pub reference_count: i32,
    pub references: Vec<String>, // 该文献参考文献 bibcode 数组
    pub citations: Vec<String>,  // 引用该文献的 bibcode 数组
    pub citation_counts: std::collections::HashMap<String, i32>, // 相关文献与被引数映射
}

// 从 SQLite 查询引用关联，生成引用星系关系树
pub async fn get_citation_network(
    State(state): State<Arc<AppState>>,
    Query(params): Query<DownloadRequest>,
) -> ApiResult<Json<CitationsResponse>> {
    let paper = match get_paper_from_db(&state.db, &state.config.library_dir, &params.bibcode).await
    {
        Ok(p) => p,
        Err(_) => {
            // 如果本地数据库查不到，尝试从 ADS 在线 API 动态获取
            if !state.config.ads_api_key.is_empty() {
                match state
                    .ads
                    .search(&format!("bibcode:{}", params.bibcode), 0, 1, "relevance")
                    .await
                {
                    Ok(docs) => {
                        if let Some(doc) = docs.first() {
                            let standard_paper = convert_ads_doc_to_standard(doc);
                            // 保存至数据库缓存，并保存引用关联
                            if let Err(e) = save_paper_to_db(&state.db, &standard_paper).await {
                                warn!("保存引用文献至数据库失败: {}", e);
                            }
                            if let Some(refs) = &doc.reference {
                                for ref_bib in refs {
                                    if let Err(e) = sqlx::query("INSERT OR IGNORE INTO citations_references (source_bibcode, target_bibcode) VALUES (?, ?)")
                                        .bind(&standard_paper.bibcode)
                                        .bind(ref_bib)
                                        .execute(&state.db)
                                        .await
                                    {
                                        warn!("保存引用关系失败 ({} -> {}): {}", standard_paper.bibcode, ref_bib, e);
                                    }
                                }
                            }
                            if let Some(cits) = &doc.citation {
                                for cit_bib in cits {
                                    if let Err(e) = sqlx::query("INSERT OR IGNORE INTO citations_references (source_bibcode, target_bibcode) VALUES (?, ?)")
                                        .bind(cit_bib)
                                        .bind(&standard_paper.bibcode)
                                        .execute(&state.db)
                                        .await
                                    {
                                        warn!("保存被引关系失败 ({} -> {}): {}", cit_bib, standard_paper.bibcode, e);
                                    }
                                }
                            }
                            standard_paper
                        } else {
                            return Err(AppError::not_found(format!(
                                "在本地库及 ADS 中均未找到该文献: {}",
                                params.bibcode
                            )));
                        }
                    }
                    Err(e) => {
                        return Err(AppError::internal(format!("在线检索文献元数据失败: {}", e)));
                    }
                }
            } else {
                return Err(AppError::not_found(format!(
                    "本地数据库未收录该文献，且未配置 ADS_API_KEY，无法在线加载: {}",
                    params.bibcode
                )));
            }
        }
    };

    // 加载引用的文献
    let refs_rows =
        sqlx::query("SELECT target_bibcode FROM citations_references WHERE source_bibcode = ?")
            .bind(&params.bibcode)
            .fetch_all(&state.db)
            .await
            .unwrap_or_else(|e| {
                warn!("查询引用关系失败: {}", e);
                Vec::new()
            });
    let references: Vec<String> = refs_rows.iter().map(|row| row.get(0)).collect();

    // 加载被引用的文献
    let cits_rows =
        sqlx::query("SELECT source_bibcode FROM citations_references WHERE target_bibcode = ?")
            .bind(&params.bibcode)
            .fetch_all(&state.db)
            .await
            .unwrap_or_else(|e| {
                warn!("查询被引关系失败: {}", e);
                Vec::new()
            });
    let citations: Vec<String> = cits_rows.iter().map(|row| row.get(0)).collect();

    // 加载关联文献的被引数量 (从 SQLite papers 表获取)
    // 优化：用 WHERE IN 批量查询替代逐条 query_scalar，避免 N+1。
    let mut citation_counts = std::collections::HashMap::new();
    let mut all_related = references.clone();
    all_related.extend(citations.clone());

    // 去重，避免重复绑定与查询
    let mut unique_bibs: Vec<String> = all_related.clone();
    unique_bibs.sort();
    unique_bibs.dedup();

    // SQLite 单条 SQL 参数上限 999，分批查询
    for chunk in unique_bibs.chunks(SQLITE_PARAM_LIMIT) {
        if chunk.is_empty() {
            continue;
        }
        let placeholders = vec!["?"; chunk.len()].join(", ");
        let sql = format!(
            "SELECT bibcode, citation_count FROM papers WHERE bibcode IN ({})",
            placeholders
        );
        let mut query = sqlx::query(&sql);
        for b in chunk {
            query = query.bind(b);
        }
        let rows = query.fetch_all(&state.db).await.unwrap_or_else(|e| {
            warn!("批量查询文献引用数失败: {}", e);
            Vec::new()
        });
        for row in rows {
            let bib: String = row.get(0);
            let count: i32 = row.get(1);
            citation_counts.insert(bib, count);
        }
    }

    Ok(Json(CitationsResponse {
        bibcode: paper.bibcode,
        title: paper.title,
        citation_count: paper.citation_count,
        reference_count: paper.reference_count,
        references,
        citations,
        citation_counts,
    }))
}

// ── GET /api/paper ──
#[derive(Serialize)]
pub struct PaperDetailResponse {
    pub paper: StandardPaper,
    pub english_content: Option<String>,
    pub translation_content: Option<String>,
}

// 获取文献标准详情和中英双语内容文件数据
pub async fn get_paper_detail(
    State(state): State<Arc<AppState>>,
    Query(params): Query<DownloadRequest>,
) -> ApiResult<Json<PaperDetailResponse>> {
    let paper = get_paper_from_db(&state.db, &state.config.library_dir, &params.bibcode)
        .await
        .map_err(|e| AppError::not_found(format!("未找到该文献数据: {}", e)))?;

    let (_, _, md_opt, tr_opt) =
        check_paper_paths_in_db(&state.db, &state.config.library_dir, &params.bibcode)
            .await
            .map_err(|e| AppError::internal(e.to_string()))?
            .unwrap_or_default();

    let english_content = match md_opt {
        Some(rel) => fs::read_to_string(state.config.library_dir.join(rel))
            .await
            .ok(),
        None => None,
    };
    let translation_content = match tr_opt {
        Some(rel) => fs::read_to_string(state.config.library_dir.join(rel))
            .await
            .ok(),
        None => None,
    };

    Ok(Json(PaperDetailResponse {
        paper,
        english_content,
        translation_content,
    }))
}

// ── GET /api/library ──
// 获取本地图书馆文献列表
pub async fn get_library(
    State(state): State<Arc<AppState>>,
) -> ApiResult<Json<Vec<StandardPaper>>> {
    let rows = sqlx::query("SELECT bibcode, title, authors, year, pub, keywords, abstract, doi, arxiv_id, citation_count, reference_count, pdf_path, html_path, markdown_path, translation_path, doctype, EXISTS(SELECT 1 FROM paper_chunks_content WHERE bibcode = papers.bibcode) FROM papers ORDER BY created_at DESC")
        .fetch_all(&state.db)
        .await
        .map_err(|e| AppError::internal(format!("访问本地数据库失败: {}", e)))?;

    let mut list = Vec::new();
    for r in rows {
        list.push(parse_paper_row(&r, &state.config.library_dir));
    }

    Ok(Json(list))
}

// ── POST /api/export ──
#[derive(Deserialize)]
pub struct ExportRequest {
    pub bibcodes: Vec<String>,
}

#[derive(Serialize)]
pub struct ExportResponse {
    pub bibtex: String,
}

// 批量请求 ADS 接口，获取选中 Bibcode 的标准 BibTeX 引文段落
pub async fn export_citations(
    State(state): State<Arc<AppState>>,
    Json(req): Json<ExportRequest>,
) -> ApiResult<Json<ExportResponse>> {
    if state.config.ads_api_key.is_empty() {
        return Err(AppError::bad_request(
            "ADS API key 未在 .env 中配置，无法使用该接口",
        ));
    }

    let bibtex = state
        .ads
        .export_bibtex(req.bibcodes)
        .await
        .map_err(|e| AppError::internal(format!("批量引文导出失败: {}", e)))?;

    Ok(Json(ExportResponse { bibtex }))
}

// ── POST /api/upload ──
// 允许手动上传/推入本地 PDF 或 HTML 文献文件
pub async fn upload_paper_file(
    State(state): State<Arc<AppState>>,
    mut multipart: axum::extract::Multipart,
) -> ApiResult<Json<StandardPaper>> {
    let mut bibcode = String::new();
    let mut file_type = String::new(); // "pdf" 或 "html"
    let mut file_bytes = Vec::new();
    let mut file_name = String::new();

    while let Some(field) = multipart
        .next_field()
        .await
        .map_err(|e| AppError::bad_request(format!("解析文件分块失败: {}", e)))?
    {
        let name = field.name().unwrap_or("").to_string();
        if name == "bibcode" {
            bibcode = field.text().await.unwrap_or_default();
        } else if name == "type" {
            file_type = field.text().await.unwrap_or_default();
        } else if name == "file" {
            file_name = field.file_name().unwrap_or("").to_string();
            file_bytes = field
                .bytes()
                .await
                .map_err(|e| AppError::internal(format!("读取文件字节流失败: {}", e)))?
                .to_vec();
        }
    }

    if bibcode.is_empty() {
        return Err(AppError::bad_request("缺少 bibcode 参数"));
    }

    // 校验 bibcode 字符安全：仅允许字母、数字、点号、冒号、连接符、斜杠
    // 防止路径遍历攻击（如 "../../etc/passwd"）
    if !bibcode
        .chars()
        .all(|c| c.is_ascii_alphanumeric() || ".:/-_".contains(c))
    {
        return Err(AppError::bad_request("bibcode 包含非法字符"));
    }

    if file_bytes.is_empty() {
        return Err(AppError::bad_request("上传文件为空或读取失败"));
    }

    // 尝试将可能的 DOI 或 arXiv ID 解析为真实的 bibcode
    let mut resolved_bibcode = bibcode.clone();
    let exists_as_bibcode = sqlx::query("SELECT bibcode FROM papers WHERE bibcode = ?")
        .bind(&resolved_bibcode)
        .fetch_optional(&state.db)
        .await
        .unwrap_or(None)
        .is_some();

    if !exists_as_bibcode {
        // 尝试匹配 DOI
        let clean_doi = resolved_bibcode
            .trim_start_matches("doi:")
            .trim_start_matches("DOI:")
            .trim_start_matches("https://doi.org/")
            .trim_start_matches("http://doi.org/")
            .trim();

        if let Some(row) = sqlx::query(
            "SELECT bibcode FROM papers WHERE doi = ? OR doi = ? OR LOWER(doi) = LOWER(?)",
        )
        .bind(clean_doi)
        .bind(&resolved_bibcode)
        .bind(clean_doi)
        .fetch_optional(&state.db)
        .await
        .unwrap_or(None)
        {
            let found: String = row.get(0);
            info!(
                "上传接口：通过 DOI 匹配成功，将 '{}' 解析为 bibcode '{}'",
                bibcode, found
            );
            resolved_bibcode = found;
        } else {
            // 尝试匹配 arXiv ID
            let clean_arxiv = resolved_bibcode
                .trim_start_matches("arxiv:")
                .trim_start_matches("arXiv:")
                .trim_start_matches("ARXIV:")
                .trim();
            // 移除可能存在的版本号后缀（如 2303.12345v1 -> 2303.12345）
            let clean_arxiv_no_version = if let Some(pos) = clean_arxiv.find('v') {
                if clean_arxiv[pos + 1..].chars().all(|c| c.is_ascii_digit()) {
                    &clean_arxiv[..pos]
                } else {
                    clean_arxiv
                }
            } else {
                clean_arxiv
            };

            if let Some(row) = sqlx::query(
                "SELECT bibcode FROM papers WHERE arxiv_id = ? OR arxiv_id = ? OR arxiv_id LIKE ? OR arxiv_id LIKE ?"
            )
            .bind(clean_arxiv)
            .bind(clean_arxiv_no_version)
            .bind(format!("{}%", clean_arxiv_no_version))
            .bind(format!("arXiv:{}%", clean_arxiv_no_version))
            .fetch_optional(&state.db)
            .await
            .unwrap_or(None) {
                let found: String = row.get(0);
                info!("上传接口：通过 arXiv ID 匹配成功，将 '{}' 解析为 bibcode '{}'", bibcode, found);
                resolved_bibcode = found;
            }
        }
    }
    let bibcode = resolved_bibcode;

    // 从数据库读取该文献元数据
    let _paper = get_paper_from_db(&state.db, &state.config.library_dir, &bibcode)
        .await
        .map_err(|e| AppError::not_found(format!("未找到该文献记录: {}", e)))?;

    // 校验并保存文件
    let is_pdf = file_type == "pdf" || file_name.to_lowercase().ends_with(".pdf");

    let relative_path = if is_pdf {
        crate::services::download::validate_pdf_content(&file_bytes)
            .map_err(|e| AppError::bad_request(format!("PDF 文件内容校验失败: {}", e)))?;
        let pdf_filename = format!("{}.pdf", bibcode);
        let pdf_dest = state.config.library_dir.join("PDF").join(&pdf_filename);
        if let Some(parent) = pdf_dest.parent() {
            std::fs::create_dir_all(parent).unwrap_or_default();
        }
        std::fs::write(&pdf_dest, &file_bytes)
            .map_err(|e| AppError::internal(format!("无法写入 PDF 文件: {}", e)))?;
        format!("PDF/{}", pdf_filename)
    } else {
        let text_content = String::from_utf8(file_bytes)
            .map_err(|_| AppError::bad_request("上传的 HTML 文件不是有效的 UTF-8 文本"))?;
        crate::services::download::validate_html_content_lenient(&text_content)
            .map_err(|e| AppError::bad_request(format!("HTML 文件内容校验失败: {}", e)))?;
        let html_filename = format!("{}.html", bibcode);
        let html_dest = state.config.library_dir.join("HTML").join(&html_filename);
        if let Some(parent) = html_dest.parent() {
            std::fs::create_dir_all(parent).unwrap_or_default();
        }
        std::fs::write(&html_dest, &text_content)
            .map_err(|e| AppError::internal(format!("无法写入 HTML 文件: {}", e)))?;
        format!("HTML/{}", html_filename)
    };

    // 更新数据库路径状态
    let path_field = if is_pdf { "pdf_path" } else { "html_path" };
    let sql = format!("UPDATE papers SET {} = ? WHERE bibcode = ?", path_field);
    sqlx::query(&sql)
        .bind(&relative_path)
        .bind(&bibcode)
        .execute(&state.db)
        .await
        .map_err(|e| AppError::internal(format!("更新数据库状态失败: {}", e)))?;

    // 重新获取最新的文献信息以更新前端界面
    let updated_paper = get_paper_from_db(&state.db, &state.config.library_dir, &bibcode)
        .await
        .map_err(|e| AppError::internal(format!("重读文献数据失败: {}", e)))?;

    Ok(Json(updated_paper))
}

// ── POST /api/no_resource ──
#[derive(Debug, Deserialize)]
pub struct MarkNoResourceRequest {
    pub bibcode: String,
    pub clear: Option<bool>,
}

pub async fn mark_no_resource(
    State(state): State<Arc<AppState>>,
    Json(req): Json<MarkNoResourceRequest>,
) -> ApiResult<Json<StandardPaper>> {
    let clear_flag = req.clear.unwrap_or(false);

    if clear_flag {
        info!("接收到清除文献无资源标记指令，标识符: {}", req.bibcode);
        sqlx::query("UPDATE papers SET pdf_path = NULL, html_path = NULL WHERE bibcode = ?")
            .bind(&req.bibcode)
            .execute(&state.db)
            .await
            .map_err(|e| AppError::internal(format!("清除无资源标记失败: {}", e)))?;
    } else {
        info!("接收到文献无资源标记指令，标识符: {}", req.bibcode);
        sqlx::query("UPDATE papers SET pdf_path = 'error:no_resource', html_path = 'error:no_resource' WHERE bibcode = ?")
            .bind(&req.bibcode)
            .execute(&state.db)
            .await
            .map_err(|e| AppError::internal(format!("更新数据库无资源标记失败: {}", e)))?;
    }

    // 重新获取最新的文献信息以更新前端界面
    let updated_paper = get_paper_from_db(&state.db, &state.config.library_dir, &req.bibcode)
        .await
        .map_err(|e| AppError::internal(format!("重读文献数据失败: {}", e)))?;

    Ok(Json(updated_paper))
}

// ── GET /api/active_bibcode ──
#[derive(Debug, Serialize)]
pub struct ActiveBibcodeResponse {
    pub bibcode: Option<String>,
}

pub async fn get_active_bibcode(State(state): State<Arc<AppState>>) -> Json<ActiveBibcodeResponse> {
    let active = state.active_bibcode.lock().await;
    Json(ActiveBibcodeResponse {
        bibcode: active.clone(),
    })
}

// ── POST /api/active_bibcode ──
#[derive(Debug, Deserialize)]
pub struct SetActiveBibcodeRequest {
    pub bibcode: Option<String>,
}

pub async fn set_active_bibcode(
    State(state): State<Arc<AppState>>,
    Json(req): Json<SetActiveBibcodeRequest>,
) -> StatusCode {
    let mut active = state.active_bibcode.lock().await;
    *active = req.bibcode;
    tracing::debug!("已更新当前活跃文献 Bibcode 标记为: {:?}", *active);
    StatusCode::OK
}

// ── POST /api/embed ──
#[derive(Debug, Deserialize)]
pub struct EmbedRequest {
    pub bibcode: String,
}

#[derive(Debug, Serialize)]
pub struct EmbedResponse {
    pub chunk_count: usize,
}

pub async fn embed_paper(
    State(state): State<Arc<AppState>>,
    Json(req): Json<EmbedRequest>,
) -> ApiResult<Json<EmbedResponse>> {
    info!("接收到文献向量化分块入库指令: {}", req.bibcode);

    let (_, _, md_opt, _) =
        check_paper_paths_in_db(&state.db, &state.config.library_dir, &req.bibcode)
            .await
            .map_err(|e| AppError::not_found(format!("获取文献路径失败: {}", e)))?
            .ok_or_else(|| AppError::not_found("该文献未注册在数据库中"))?;

    let md_rel =
        md_opt.ok_or_else(|| AppError::bad_request("文献尚未解析为 Markdown，请先执行解析"))?;
    let md_abs = state.config.library_dir.join(&md_rel);
    if !md_abs.exists() {
        return Err(AppError::not_found("文献 Markdown 文件未找到，请重新解析"));
    }

    let markdown_content = fs::read_to_string(&md_abs)
        .await
        .map_err(|e| AppError::internal(format!("读取 Markdown 文件失败: {}", e)))?;

    let chunk_count = crate::services::rag::ingest_paper(
        &state.db,
        &state.embedding,
        &req.bibcode,
        &markdown_content,
        None,
    )
    .await
    .map_err(|e| AppError::internal(format!("文献向量化失败: {}", e)))?;

    Ok(Json(EmbedResponse { chunk_count }))
}