//! 处理管线 — 批量处理相册元数据
//!
//! 核心架构：脏集追踪 + 增量解析
//!
//!   Phase 0  清洗标签标点
//!   Phase A1 检测标签中的人名并直接提取到 person 字段 → 加入脏集
//!   Phase A2 清理非人物       → 加入脏集
//!   Phase A3 收集新相册/半成品 → 加入脏集
//!   Phase 1  解析脏集相册（增量解析，不扫全库）
//!   Phase 2  人物合并
//!   Phase B  后校验标签中的人名
//!
//! 脏集（DirtySet）贯穿各阶段，每个阶段发现的"需要重新解析"的相册都会加入脏集，
//! 最终只处理脏集里的相册，而非全库扫描，大幅提升效率。

use crate::db::Database;
use crate::engine::title_parser;
use crate::engine::tag_extractor;
use crate::engine::person_merger;
use std::collections::HashSet;

// ════════════════════════════════════════════════
//  脏集 — 追踪需要重新解析的相册 ID
// ════════════════════════════════════════════════

/// 脏集：记录哪些相册需要重新解析
pub struct DirtySet {
    ids: HashSet<String>,
}

impl DirtySet {
    pub fn new() -> Self { Self { ids: HashSet::new() } }
    pub fn add(&mut self, id: &str) { self.ids.insert(id.to_string()); }
    pub fn extend(&mut self, ids: impl IntoIterator<Item = String>) { self.ids.extend(ids); }
    pub fn contains(&self, id: &str) -> bool { self.ids.contains(id) }
    pub fn len(&self) -> usize { self.ids.len() }
    pub fn is_empty(&self) -> bool { self.ids.is_empty() }
    pub fn into_inner(self) -> HashSet<String> { self.ids }
}

// ════════════════════════════════════════════════
//  Phase 0：清洗已有标签中的头尾标点
// ════════════════════════════════════════════════

pub async fn phase_clean_tags(db: &Database) -> usize {
    let albums = db.get_all_albums_full().await;
    let mut cleaned_count = 0usize;
    let mut removed_tags = HashSet::new();

    for album in &albums {
        let tags_json = match album.tags.as_deref() {
            Some(t) if !t.is_empty() && t != "[]" => t,
            _ => continue,
        };
        let old_tags: Vec<String> = match serde_json::from_str(tags_json) {
            Ok(t) => t, Err(_) => continue,
        };
        if old_tags.is_empty() { continue; }

        let mut changed = false;
        let mut new_tags = Vec::new();
        for tag in old_tags {
            let cleaned = match tag_extractor::clean_tag(&tag) {
                Some(t) => t,
                None => { removed_tags.insert(tag); changed = true; continue; }
            };
            if cleaned != tag { removed_tags.insert(tag); changed = true; }
            new_tags.push(cleaned);
        }
        if !changed { continue; }
        cleaned_count += 1;

        let tags_json_new = serde_json::to_string(&new_tags).unwrap_or_else(|_| "[]".to_string());
        let all_words_json = album.all_words.as_deref().unwrap_or("[]");
        let all_words_new: Vec<[String; 2]> = serde_json::from_str::<Vec<[String; 2]>>(all_words_json)
            .unwrap_or_default()
            .into_iter()
            .filter_map(|pair| { let cleaned = tag_extractor::clean_tag(&pair[0])?; Some([cleaned, pair[1].clone()]) })
            .collect();
        let all_words_json_new = serde_json::to_string(&all_words_new).unwrap_or_else(|_| "[]".to_string());
        db.update_album_tags(&album.id, &tags_json_new, &all_words_json_new).await;
    }

    if cleaned_count > 0 {
        println!("[管线·Phase0] 标签清洗完成：清洗 {} 个相册，移除标签: {:?}",
                 cleaned_count, removed_tags.iter().collect::<Vec<_>>());
    } else {
        println!("[管线·Phase0] 标签清洗完成：无需要清洗的标签");
    }
    cleaned_count
}

// ════════════════════════════════════════════════
//  Phase A1：检测标签中的人名并直接提取到 person 字段
// ════════════════════════════════════════════════

/// Phase A1：检测标签中可能的人名并直接提取到 person_name
///
/// 核心变化：不再只标记脏集等待 Phase 1，而是直接从 tags 中提取人名写入 person 字段。
/// 因为 tags 中的人名比从 title 重解析更直接、更准确。
///
/// 两层检测 + 最终写入：
///   1. 逐个标签 — 标签是已知人物或像人名 → 收集为候选人名（中文加权）
///   2. jieba 合并（空格分隔）— 发现跨标签拆分的人名（["杨晨","晨Yome"]）
///   3. 最佳候选人名 → 写入 person_name，从标签中移除关联标签
///
/// 返回 (脏集, 从标签中移除的人名标签数)
pub async fn phase_detect_person_in_tags(db: &Database) -> (DirtySet, usize) {
    let albums = db.get_all_albums_full().await;
    let mut dirty = DirtySet::new();
    let mut person_like_removed = 0usize;

    let known_persons: HashSet<String> = db.get_all_person_names().await
        .into_iter().map(|(n, _)| n.to_lowercase()).collect();

    for album in &albums {
        let tags_json = match album.tags.as_deref() {
            Some(t) if !t.is_empty() && t != "[]" => t,
            _ => continue,
        };
        let old_tags: Vec<String> = match serde_json::from_str(tags_json) {
            Ok(t) => t, Err(_) => continue,
        };

        let has_person = album.person_name_original.as_deref()
            .map(|s| !s.is_empty()).unwrap_or(false);

        // 快速判断是否需要处理
        let has_known_tag = old_tags.iter().any(|t| known_persons.contains(&t.to_lowercase()));
        let has_like_tag = !has_person && old_tags.iter().any(|t|
            title_parser::is_likely_person_name(t) && !title_parser::is_excluded_name(t));
        if has_person && !has_known_tag && !has_like_tag { continue; }

        // ── 第一层：逐个标签收集候选人名 ──
        let mut known_person_found: Option<String> = None;
        let mut person_like_tags: Vec<String> = Vec::new();

        for tag in &old_tags {
            let tag_lower = tag.to_lowercase();
            if known_persons.contains(&tag_lower) {
                known_person_found = Some(tag.clone());
                continue;
            }
            if !has_person && title_parser::is_likely_person_name(tag) && !title_parser::is_excluded_name(tag) {
                person_like_tags.push(tag.clone());
                continue;
            }
        }

        // 从 person_like_tags 中选最优（中文加权）
        let best_layer1 = person_like_tags.into_iter().max_by_key(|t| {
            if let Some(cn) = title_parser::extract_cn(t) {
                if cn.len() >= 2 { cn.len() * 10 + t.len() } else { t.len() }
            } else { t.len() }
        });

        // ── 第二层：空格连接所有标签，用 jieba 提取人名 ──
        let combined = old_tags.join(" ");
        let (jieba_name, _) = title_parser::extract_person_and_tags(&combined);

        // ── 确定最终人名 ──
        let final_person = known_person_found.or_else(|| {
            match (&jieba_name, &best_layer1) {
                (Some(j), Some(b)) => {
                    // jieba 结果更完整 → 用 jieba
                    if j.len() > b.len() || title_parser::is_excluded_name(b) { Some(j.clone()) } else { Some(b.clone()) }
                }
                (Some(j), None) => Some(j.clone()),
                (None, Some(b)) => Some(b.clone()),
                (None, None) => None,
            }
        });

        if let Some(ref person_name) = final_person {
            // ── 从标签中移除所有人名相关标签 ──
            let mut changed = false;
            let mut clean_tags: Vec<String> = Vec::new();
            let person_lower = person_name.to_lowercase();
            let (primary_cleaned, _) = title_parser::split_person_name_with_aliases(person_name);
            let primary_lower = primary_cleaned.to_lowercase();

            for tag in &old_tags {
                let tag_lower = tag.to_lowercase();
                let should_remove =
                    tag_lower == person_lower                               // 完全匹配
                    || tag_lower == primary_lower                           // 中文核心匹配
                    || (tag.len() >= 2 && tag.chars().all(|c| c.is_ascii_alphabetic())
                        && !tag_lower.starts_with("cos")
                        && person_lower.contains(&tag_lower))              // 英文后缀
                    || (tag_lower.len() >= 2 && person_lower.contains(&tag_lower)); // 人名包含

                if should_remove {
                    person_like_removed += 1;
                    changed = true;
                    continue;
                }
                clean_tags.push(tag.clone());
            }

            if changed || !has_person {
                // ── 写入 person_name（直接提取，无需等待 Phase 1）──
                let (primary, aliases) = title_parser::split_person_name_with_aliases(person_name);
                let final_name = if primary.is_empty() { person_name.clone() } else { primary };

                // 用事务包裹所有写入，避免逐条 autocommit 导致巨慢
                let mut tx = db.pool.begin().await.expect("begin tx");
                db.update_album_person_with_tx(&mut tx, &album.id, person_name, &final_name).await;

                if !title_parser::is_excluded_name(&final_name) {
                    let pid = db.insert_person_with_tx(&mut tx, &final_name, None).await;
                    db.insert_person_album_with_tx(&mut tx, pid, &album.id).await;
                    for (at, an) in &aliases {
                        if !an.is_empty() && an != &final_name {
                            db.insert_person_alias_with_tx(&mut tx, pid, at, an).await;
                        }
                    }
                    db.update_person_counts_with_tx(&mut tx, pid).await;
                }

                // ── 写入清理后的标签 ──
                let tags_json_new = serde_json::to_string(&clean_tags).unwrap_or_else(|_| "[]".to_string());
                let all_words_json = album.all_words.as_deref().unwrap_or("[]");
                let all_words_new: Vec<[String; 2]> = serde_json::from_str::<Vec<[String; 2]>>(all_words_json)
                    .unwrap_or_default()
                    .into_iter()
                    .filter(|pair| !known_persons.contains(&pair[0].to_lowercase()))
                    .collect();
                let words_json_new = serde_json::to_string(&all_words_new).unwrap_or_else(|_| "[]".to_string());
                db.update_album_tags_with_tx(&mut tx, &album.id, &tags_json_new, &words_json_new).await;

                tx.commit().await.expect("commit tx");

                if has_person { dirty.add(&album.id); }
            }
        }
    }

    if person_like_removed > 0 {
        println!("[管线·PhaseA1] 从标签中检测并提取人名：移除 {} 个人名标签，写入 {} 个相册的 person 字段",
                 person_like_removed, dirty.len());
    } else {
        println!("[管线·PhaseA1] 检测标签中的人名：无异常");
    }
    (dirty, person_like_removed)
}

// ════════════════════════════════════════════════
//  Phase A2：清理 persons 表中的非人物
// ════════════════════════════════════════════════

pub async fn phase_clean_persons(db: &Database) -> (DirtySet, usize) {
    let persons = db.get_all_persons_with_counts().await;
    let mut dirty = DirtySet::new();
    let mut deleted = 0usize;

    for (pid, name, _albums, _images) in &persons {
        if title_parser::is_excluded_name(name) || !title_parser::is_likely_person_name(name) {
            let album_list = db.get_person_albums(*pid).await;
            let album_ids: Vec<String> = album_list.into_iter().map(|a| a.id.to_string()).collect();
            for aid in &album_ids { dirty.add(aid); }
            println!("[管线·PhaseA2] 删除非人物：{} (id={})，释放 {} 个相册", name, pid, album_ids.len());
            db.update_album_person_by_person_id(*pid).await;
            db.delete_person_completely(*pid).await;
            deleted += 1;
        }
    }

    if deleted > 0 {
        println!("[管线·PhaseA2] 清理完成：删除 {} 个非人物，标记 {} 个脏相册", deleted, dirty.len());
    } else {
        println!("[管线·PhaseA2] 清理完成：无非人物需要删除");
    }
    (dirty, deleted)
}

// ════════════════════════════════════════════════
//  Phase A3：收集新相册 + 半成品
// ════════════════════════════════════════════════

pub async fn phase_collect_new_albums(db: &Database) -> DirtySet {
    let albums = db.get_all_albums_full().await;
    let mut dirty = DirtySet::new();
    let mut new_count = 0usize;
    let mut partial_count = 0usize;

    for album in &albums {
        let tags_empty = album.tags.as_deref()
            .map(|t| t.is_empty() || t == "[]" || t == "null").unwrap_or(true);
        if tags_empty { dirty.add(&album.id); new_count += 1; continue; }

        let has_person = album.person_name_original.as_deref()
            .map(|s| !s.is_empty()).unwrap_or(false);
        if !has_person { dirty.add(&album.id); partial_count += 1; }
    }

    println!("[管线·PhaseA3] 收集相册：{} 个全新，{} 个半成品，脏集合计 {} 个", new_count, partial_count, dirty.len());
    dirty
}

// ════════════════════════════════════════════════
//  Phase 1：增量解析 — 只处理脏集中的相册
// ════════════════════════════════════════════════

pub async fn phase_parse_dirty(db: &Database, dirty_set: &DirtySet) -> (usize, usize) {
    if dirty_set.is_empty() {
        println!("[管线·Phase1] 增量解析跳过：脏集为空");
        return (0, 0);
    }

    let albums = db.get_all_albums_full().await;
    let patterns = person_merger::collect_person_patterns(db).await;
    let use_patterns = !patterns.is_empty();
    let mut person_updated = 0usize;
    let mut tag_updated = 0usize;
    let mut skipped = 0usize;

    for album in &albums {
        if !dirty_set.contains(&album.id) { continue; }
        let title = album.title.as_deref().unwrap_or("");
        if title.is_empty() { skipped += 1; continue; }

        let (jieba_person, jieba_tags) = title_parser::extract_person_and_tags(title);

        let best_person = if use_patterns {
            person_merger::match_title(title, &patterns)
                .map(|(_, name, _)| name).or(jieba_person)
        } else {
            jieba_person
        };

        // 用事务包裹所有写入，避免逐条 autocommit 导致巨慢
        let mut pending_tx: Option<sqlx::Transaction<'_, sqlx::Sqlite>> = None;

        if let Some(name) = &best_person {
            let (primary, aliases) = title_parser::split_person_name_with_aliases(name);
            let final_name = if primary.is_empty() { name.clone() } else { primary };
            let mut tx = db.pool.begin().await.expect("begin tx");
            db.update_album_person_with_tx(&mut tx, &album.id, name, &final_name).await;
            let pid = db.insert_person_with_tx(&mut tx, &final_name, None).await;
            db.insert_person_album_with_tx(&mut tx, pid, &album.id).await;
            for (at, an) in &aliases {
                if !an.is_empty() && an != &final_name {
                    db.insert_person_alias_with_tx(&mut tx, pid, at, an).await;
                }
            }
            db.update_person_counts_with_tx(&mut tx, pid).await;
            pending_tx = Some(tx);
            person_updated += 1;
        }

        // 确定标签排除用的人名 — 用最完整的名字
        // 优先级：person_name_original(完整含英文后缀) > best_person > person_name_cleaned(仅中文)
        let exclude_person = album.person_name_original.as_deref()
            .filter(|s| !s.is_empty())
            .or_else(|| best_person.as_deref())
            .or_else(|| album.person_name_cleaned.as_deref().filter(|s| !s.is_empty()));

        let mut raw_tags = tag_extractor::extract_tags_from_title(title, exclude_person);
        raw_tags.extend(jieba_tags);
        let unique = tag_extractor::unique_tags(raw_tags);
        let tag_names: Vec<String> = unique.iter().map(|(t, _)| t.clone()).collect();

        if !tag_names.is_empty() {
            let tags_json = serde_json::to_string(&tag_names).unwrap_or_else(|_| "[]".to_string());
            let all_words: Vec<[String; 2]> = unique.iter().map(|(t, tp)| [t.clone(), tp.clone()]).collect();
            let words_json = serde_json::to_string(&all_words).unwrap_or_else(|_| "[]".to_string());
            let mut tx = match pending_tx.take() {
                Some(t) => t,
                None => db.pool.begin().await.expect("begin tx"),
            };
            db.update_album_tags_with_tx(&mut tx, &album.id, &tags_json, &words_json).await;
            tx.commit().await.expect("commit tx");
            tag_updated += 1;
        } else if let Some(tx) = pending_tx.take() {
            // 只有 person 写入，没有标签写入
            tx.commit().await.expect("commit tx");
        }
    }

    println!("[管线·Phase1] 增量解析完成：脏集 {} 个，处理 {} 个，跳过 {} 个，更新人名 {} 个，更新标签 {} 个",
             dirty_set.len(), person_updated.max(tag_updated), skipped, person_updated, tag_updated);
    (person_updated, tag_updated)
}

// ════════════════════════════════════════════════
//  Phase 2：人物合并
// ════════════════════════════════════════════════

pub async fn phase_merge_persons(db: &Database) -> (usize, usize) {
    let result = person_merger::execute_merge(db).await;
    if result.persons_merged > 0 {
        println!("[管线·Phase2] 人物合并完成：分析 {} 组，合并 {} 人，迁移 {} 个别名",
                 result.groups_analyzed, result.persons_merged, result.aliases_moved);
    } else {
        println!("[管线·Phase2] 人物合并完成：无需要合并的人物");
    }
    (result.persons_merged, result.aliases_moved)
}

// ════════════════════════════════════════════════
//  Phase B：后校验标签 — 用合并后的人名检查
// ════════════════════════════════════════════════

pub async fn phase_clean_tags_after_parse(db: &Database) -> usize {
    let albums = db.get_all_albums_full().await;
    let all_person_names: HashSet<String> = db.get_all_person_names().await
        .into_iter().map(|(n, _)| n.to_lowercase()).collect();
    let all_aliases: HashSet<String> = db.get_all_aliases().await
        .into_iter().map(|(a, _)| a.to_lowercase()).collect();
    let person_or_alias: HashSet<String> = all_person_names.into_iter().chain(all_aliases).collect();

    if person_or_alias.is_empty() {
        println!("[管线·PhaseB] 后校验标签完成：无人物数据，跳过");
        return 0;
    }

    let mut tag_removed = 0usize;
    for album in &albums {
        let tags_json = match album.tags.as_deref() {
            Some(t) if !t.is_empty() && t != "[]" => t, _ => continue,
        };
        let old_tags: Vec<String> = match serde_json::from_str(tags_json) { Ok(t) => t, Err(_) => continue, };

        let mut album_removed = 0usize;
        let good_tags: Vec<String> = old_tags.into_iter().filter(|t| {
            if person_or_alias.contains(&t.to_lowercase()) { album_removed += 1; false } else { true }
        }).collect();

        if album_removed == 0 { continue; }
        tag_removed += album_removed;

        let all_words_json = album.all_words.as_deref().unwrap_or("[]");
        let all_words_new: Vec<[String; 2]> = serde_json::from_str::<Vec<[String; 2]>>(all_words_json)
            .unwrap_or_default().into_iter().filter(|pair| !person_or_alias.contains(&pair[0].to_lowercase())).collect();

        let tags_json_new = serde_json::to_string(&good_tags).unwrap_or_else(|_| "[]".to_string());
        let words_json_new = serde_json::to_string(&all_words_new).unwrap_or_else(|_| "[]".to_string());
        db.update_album_tags(&album.id, &tags_json_new, &words_json_new).await;
    }

    if tag_removed > 0 {
        println!("[管线·PhaseB] 后校验标签完成：移除 {} 个人名/别名", tag_removed);
    } else {
        println!("[管线·PhaseB] 后校验标签完成：无需要修复的标签");
    }
    tag_removed
}

// ════════════════════════════════════════════════
//  Pipeline 一键执行（7 阶段）
// ════════════════════════════════════════════════

#[derive(Debug, Clone, Default)]
pub struct PipelineResult {
    pub tags_cleaned: usize,              // Phase 0
    pub person_like_tags_removed: usize,  // Phase A1
    pub dirty_albums_detected: usize,     // A1+A2+A3
    pub non_persons_deleted: usize,       // Phase A2
    pub new_albums_found: usize,          // Phase A3
    pub persons_updated: usize,           // Phase 1
    pub tags_updated: usize,              // Phase 1
    pub persons_merged: usize,            // Phase 2
    pub aliases_moved: usize,             // Phase 2
    pub tags_removed_person: usize,       // Phase B
}

/// 一键执行完整管线（7 阶段顺序串行）
pub async fn run_pipeline(db: &Database) -> PipelineResult {
    let tags_cleaned = phase_clean_tags(db).await;
    let (dirty_a1, person_like_tags_removed) = phase_detect_person_in_tags(db).await;
    let (dirty_a2, non_persons_deleted) = phase_clean_persons(db).await;
    let dirty_a3 = phase_collect_new_albums(db).await;
    let new_albums_found = dirty_a3.len();

    let mut master_dirty = DirtySet::new();
    master_dirty.extend(dirty_a1.into_inner());
    master_dirty.extend(dirty_a2.into_inner());
    master_dirty.extend(dirty_a3.into_inner());
    let dirty_albums_detected = master_dirty.len();

    let (persons_updated, tags_updated) = phase_parse_dirty(db, &master_dirty).await;
    let (persons_merged, aliases_moved) = phase_merge_persons(db).await;
    let tags_removed_person = phase_clean_tags_after_parse(db).await;

    PipelineResult {
        tags_cleaned, person_like_tags_removed, dirty_albums_detected,
        non_persons_deleted, new_albums_found,
        persons_updated, tags_updated, persons_merged,
        aliases_moved, tags_removed_person,
    }
}