//! 项目相关命令

use std::path::Path;

use serde::{Deserialize, Serialize};
use tauri::State;

use df_ai::provider::{ChatMessage, CompletionRequest};
use df_core::types::new_id;
use df_project::scan::{collect_sample, detect_stack, extract_description, normalize_path};
use df_storage::models::ProjectRecord;

use crate::state::AppState;

use super::now_millis;

/// 创建项目入参
#[derive(Debug, Deserialize)]
pub struct CreateProjectInput {
    pub name: String,
    #[serde(default)]
    pub description: String,
    pub idea_id: Option<String>,
    /// 绑定的本地代码目录(可选,空=不绑定)
    #[serde(default)]
    pub path: Option<String>,
    /// 技术栈 JSON 数组字符串(可选,空则自动探测)
    #[serde(default)]
    pub stack: Option<String>,
}

/// 列出未删除项目(过滤回收站)
#[tauri::command]
pub async fn list_projects(state: State<'_, AppState>) -> Result<Vec<ProjectRecord>, String> {
    state.projects.list_active().await.map_err(|e| e.to_string())
}

/// 创建项目，返回完整记录
///
/// 绑定目录时(path 非空):校验目录存在 + 防重复绑定 + 自动探测技术栈(stack 为空时)。
#[tauri::command]
pub async fn create_project(
    state: State<'_, AppState>,
    input: CreateProjectInput,
) -> Result<ProjectRecord, String> {
    // 绑定目录:校验存在 + 防重复 + 自动探测技术栈
    let (path, stack) = match input.path.as_deref().map(str::trim).filter(|p| !p.is_empty()) {
        Some(p) => {
            if !Path::new(p).is_dir() {
                return Err(format!("目录不存在: {p}"));
            }
            if let Some(conflict) = find_binding_conflict(&state, p, None).await? {
                return Err(format!("目录已被项目「{}」绑定", conflict.name));
            }
            // stack 优先用入参,否则自动探测(spawn_blocking 防 IO 阻塞 tokio runtime)
            let stack_json = match input.stack.as_deref().map(str::trim).filter(|s| !s.is_empty()) {
                Some(s) => s.to_string(),
                None => {
                    let root = std::path::PathBuf::from(p);
                    let detected = tokio::task::spawn_blocking(move || detect_stack(&root))
                        .await
                        .map_err(|e| e.to_string())?
                        .map_err(|e| e.to_string())?;
                    serde_json::to_string(&detected).map_err(|e| e.to_string())?
                }
            };
            (Some(p.to_string()), Some(stack_json))
        }
        None => (None, None),
    };

    let now = now_millis();
    let record = ProjectRecord {
        id: new_id(),
        name: input.name,
        description: input.description,
        status: "planning".to_string(),
        idea_id: input.idea_id,
        path,
        stack,
        created_at: now.clone(),
        updated_at: now,
    };
    state
        .projects
        .insert(record.clone())
        .await
        .map_err(|e| e.to_string())?;
    Ok(record)
}

/// 导入历史项目入参
#[derive(Debug, Deserialize)]
pub struct ImportProjectInput {
    /// 待导入的本地目录绝对路径(已存在)
    pub path: String,
    /// 项目名(可选,空=用目录名)
    #[serde(default)]
    pub name: Option<String>,
    /// 描述(可选,空=自动读 README 首段)
    #[serde(default)]
    pub description: Option<String>,
    /// 技术栈 JSON 数组字符串(可选,空=自动探测)
    #[serde(default)]
    pub stack: Option<String>,
}

/// 导入历史项目 — 用户选已存在的本地目录,复用 scan 探测 + 绑定一步创建项目记录。
///
/// 与 `create_project` 的区别:import 直接给 path,创建实体 + 绑定目录 + 探测栈 +
/// (可选)读 README 首段填 description 一次性完成,无需先建空项目再绑定。
///
/// 流程:校验目录存在 → normalize_path 防重复绑定 → detect_stack + extract_description
/// (spawn_blocking 防 IO 阻塞 tokio runtime)→ 拼记录 insert → 返回。
#[tauri::command]
pub async fn import_project(
    state: State<'_, AppState>,
    input: ImportProjectInput,
) -> Result<ProjectRecord, String> {
    let path = input.path.trim().to_string();
    if path.is_empty() {
        return Err("导入路径不能为空".to_string());
    }
    if !Path::new(&path).is_dir() {
        return Err(format!("目录不存在: {path}"));
    }
    // 防重复绑定(normalize_path 规范化比较,防正反斜杠/末尾斜杠绕过)
    if let Some(conflict) = find_binding_conflict(&state, &path, None).await? {
        return Err(format!("目录已被项目「{}」绑定", conflict.name));
    }

    // 探测栈 + 读 description(spawn_blocking 防 IO 阻塞 tokio runtime)
    let root = std::path::PathBuf::from(&path);
    let want_name = input.name.clone();
    let want_desc = input.description.clone();
    let want_stack = input.stack.clone();
    let (name, description, stack_json) = tokio::task::spawn_blocking(move || -> Result<_, String> {
        // name: 入参优先,否则取目录名
        let name = match want_name.as_deref().map(str::trim).filter(|s| !s.is_empty()) {
            Some(n) => n.to_string(),
            None => root
                .file_name()
                .and_then(|n| n.to_str())
                .map(|s| s.to_string())
                .ok_or_else(|| "无法从路径解析项目名".to_string())?,
        };
        // description: 入参优先,否则读 README 首段
        let description = match want_desc.as_deref().map(str::trim).filter(|s| !s.is_empty()) {
            Some(d) => d.to_string(),
            None => extract_description(&root).unwrap_or_default(),
        };
        // stack: 入参优先,否则自动探测
        let stack_json = match want_stack.as_deref().map(str::trim).filter(|s| !s.is_empty()) {
            Some(s) => s.to_string(),
            None => {
                let detected = detect_stack(&root).map_err(|e| e.to_string())?;
                serde_json::to_string(&detected).map_err(|e| e.to_string())?
            }
        };
        Ok((name, description, stack_json))
    })
    .await
    .map_err(|e| e.to_string())??;

    let now = now_millis();
    let record = ProjectRecord {
        id: new_id(),
        name,
        description,
        status: "planning".to_string(),
        idea_id: None,
        path: Some(path),
        stack: Some(stack_json),
        created_at: now.clone(),
        updated_at: now,
    };
    state
        .projects
        .insert(record.clone())
        .await
        .map_err(|e| e.to_string())?;
    Ok(record)
}

/// 按 ID 查询项目
#[tauri::command]
pub async fn get_project(
    state: State<'_, AppState>,
    id: String,
) -> Result<Option<ProjectRecord>, String> {
    state
        .projects
        .get_by_id(&id)
        .await
        .map_err(|e| e.to_string())
}

/// 更新项目单个字段（字段名走 df-storage 白名单校验）
#[tauri::command]
pub async fn update_project(
    state: State<'_, AppState>,
    id: String,
    field: String,
    value: String,
) -> Result<bool, String> {
    state
        .projects
        .update_field(&id, &field, &value)
        .await
        .map_err(|e| e.to_string())
}

/// 删除项目(软删 → 回收站,可恢复)
#[tauri::command]
pub async fn delete_project(state: State<'_, AppState>, id: String) -> Result<bool, String> {
    state.projects.soft_delete(&id).await.map_err(|e| e.to_string())
}

/// 列出回收站项目(deleted_at IS NOT NULL)
#[tauri::command]
pub async fn list_deleted_projects(
    state: State<'_, AppState>,
) -> Result<Vec<ProjectRecord>, String> {
    state.projects.list_deleted().await.map_err(|e| e.to_string())
}

/// 恢复项目(从回收站还原,清 deleted_at)
#[tauri::command]
pub async fn restore_project(state: State<'_, AppState>, id: String) -> Result<bool, String> {
    state.projects.restore(&id).await.map_err(|e| e.to_string())
}

/// 彻底删除项目(级联物理删 branches/releases/tasks,不可恢复)
#[tauri::command]
pub async fn purge_project(state: State<'_, AppState>, id: String) -> Result<bool, String> {
    state
        .projects
        .purge_with_descendants(&id)
        .await
        .map_err(|e| e.to_string())
}

// ============================================================
// 项目目录绑定 — 探测 / 防重复 / 重定位 / 有效性检查
// ============================================================

/// 查找已绑定该目录的项目(排除 exclude_id 自身)。无冲突返回 None。
///
/// 委托 `ProjectRepo::find_path_conflict`(DRY R-PD-11:与 tool_registry::bind_dir_to_project
/// 共用同一防重复绑定实现)。normalize_path 内含 canonicalize,防 `C:\a\b` vs `C:/a/b/` 绕过。
async fn find_binding_conflict(
    state: &AppState,
    path: &str,
    exclude_id: Option<&str>,
) -> Result<Option<ProjectRecord>, String> {
    let norm = normalize_path(path);
    state
        .projects
        .find_path_conflict(&norm, exclude_id)
        .await
        .map_err(|e| e.to_string())
}

/// 探测目录技术栈(前端选目录后实时预览)
#[tauri::command]
pub async fn scan_project_stack(path: String) -> Result<Vec<String>, String> {
    let root = std::path::PathBuf::from(&path);
    tokio::task::spawn_blocking(move || detect_stack(&root).map_err(|e| e.to_string()))
        .await
        .map_err(|e| e.to_string())?
}

/// 检查目录是否已被其他项目绑定(防重复绑定)。返回占用项目(若有)。
/// exclude_id 用于编辑/重定位时排除自身。
#[tauri::command]
pub async fn check_path_binding(
    state: State<'_, AppState>,
    path: String,
    exclude_id: Option<String>,
) -> Result<Option<ProjectRecord>, String> {
    find_binding_conflict(&state, &path, exclude_id.as_deref()).await
}

/// 重定位项目目录(目录移动后重新指向)。校验存在 + 防重复 + 重探测 stack,返回最新记录。
#[tauri::command]
pub async fn relocate_project_path(
    state: State<'_, AppState>,
    id: String,
    new_path: String,
) -> Result<ProjectRecord, String> {
    if !Path::new(&new_path).is_dir() {
        return Err(format!("目录不存在: {new_path}"));
    }
    if let Some(conflict) = find_binding_conflict(&state, &new_path, Some(&id)).await? {
        return Err(format!("目录已被项目「{}」绑定", conflict.name));
    }
    // 重探测技术栈(spawn_blocking 防 IO 阻塞 tokio runtime)
    let root = std::path::PathBuf::from(&new_path);
    let stack = tokio::task::spawn_blocking(move || detect_stack(&root))
        .await
        .map_err(|e| e.to_string())?
        .map_err(|e| e.to_string())?;
    let stack_json = serde_json::to_string(&stack).map_err(|e| e.to_string())?;
    state
        .projects
        .update_field(&id, "path", &new_path)
        .await
        .map_err(|e| e.to_string())?;
    state
        .projects
        .update_field(&id, "stack", &stack_json)
        .await
        .map_err(|e| e.to_string())?;
    state
        .projects
        .get_by_id(&id)
        .await
        .map_err(|e| e.to_string())?
        .ok_or_else(|| "项目不存在".to_string())
}

/// 检查目录是否存在(详情页「目录是否还在」用)
#[tauri::command]
pub async fn check_path_exists(path: String) -> Result<bool, String> {
    Ok(Path::new(&path).is_dir())
}

// ============================================================
// AI 扫描项目 — LLM 分析采样自动填基础信息
// ============================================================

/// AI 扫描项目结果(预览用,用户确认后填入 ProjectRecord)
#[derive(Debug, Serialize)]
pub struct AiScanResult {
    /// LLM 产出的项目摘要(空=LLM 未得出,前端提示手填)
    pub description: String,
    /// 技术栈(规则探测 ∪ LLM 推断,去重小写)
    pub stack: Vec<String>,
    /// 项目类型(web/api/cli/library/desktop/mobile/monorepo/other)
    pub project_type: Option<String>,
    /// LLM 原始返回(降级时含错误信息,前端可展示)
    pub raw: Option<String>,
}

/// AI 扫描项目目录,自动分析基础信息(description/stack/project_type)
///
/// 规则探测(detect_stack)兜底 + LLM 分析采样产出摘要。LLM 失败/解析失败降级纯规则。
/// 需已配置默认 AI provider(无则报错提示去设置)。
#[tauri::command]
pub async fn scan_project_with_ai(
    state: State<'_, AppState>,
    path: String,
) -> Result<AiScanResult, String> {
    let root = Path::new(&path);
    if !root.is_dir() {
        return Err(format!("目录不存在: {path}"));
    }

    // 1. 规则探测(兜底)+ 采样(纯 IO 轻量,spawn_blocking 防 IO 阻塞 tokio runtime)
    let scan_root = std::path::PathBuf::from(&path);
    let (rule_stack, sample) = tokio::task::spawn_blocking(move || {
        let stack = detect_stack(&scan_root)?;
        let sample = collect_sample(&scan_root)?;
        Ok::<_, anyhow::Error>((stack, sample))
    })
    .await
    .map_err(|e| e.to_string())?
    .map_err(|e| e.to_string())?;

    // 2. 取默认 provider(优先 is_default,否则首个)
    let providers = state.ai_providers.list_all().await.map_err(|e| e.to_string())?;
    let pc = providers
        .iter()
        .find(|p| p.is_default)
        .cloned()
        .or_else(|| providers.into_iter().next())
        .ok_or_else(|| "未配置 AI 提供商,请先在设置中添加".to_string())?;

    // 3. 构造 provider + LLM 调用(非流式)
    // build_provider_for 含空 key 早失败:Err → 走纯规则降级(与下方 LLM 失败降级行为一致)
    let provider = match crate::commands::ai::secret::build_provider_for(&pc) {
        Ok(p) => p,
        Err(e) => {
            return Ok(AiScanResult {
                description: String::new(),
                stack: rule_stack,
                project_type: None,
                raw: Some(format!("LLM 调用失败: provider 密钥不可用: {e}")),
            });
        }
    };
    let request = CompletionRequest {
        model: pc.default_model.clone(),
        messages: build_scan_prompt(&sample, &rule_stack),
        temperature: Some(0.2),
        max_tokens: Some(400),
        stream: false,
        tools: None,
        tool_choice: None,
    };

    // 4. 双层限流 + complete
    let _global_permit = state.llm_concurrency.acquire_global().await;
    let _per_conv_permit = state.llm_concurrency.acquire_per_conv().await;
    let llm_result = provider.complete(request).await;

    // 5. 解析 + 合并 stack(LLM 失败降级纯规则)
    match llm_result {
        Ok(resp) => {
            let raw = resp.text.clone();
            match parse_scan_result(&resp.text) {
                Some(p) => {
                    let mut stack = rule_stack;
                    for s in p.stack {
                        let s = s.trim().to_lowercase();
                        if !s.is_empty() && !stack.contains(&s) {
                            stack.push(s);
                        }
                    }
                    Ok(AiScanResult { description: p.description, stack, project_type: p.project_type, raw: Some(raw) })
                }
                None => Ok(AiScanResult { description: String::new(), stack: rule_stack, project_type: None, raw: Some(raw) }),
            }
        }
        Err(e) => Ok(AiScanResult {
            description: String::new(),
            stack: rule_stack,
            project_type: None,
            raw: Some(format!("LLM 调用失败: {e}")),
        }),
    }
}

struct ParsedScan {
    description: String,
    stack: Vec<String>,
    project_type: Option<String>,
}

/// 拼 LLM 扫描 prompt(system + 采样信息)
fn build_scan_prompt(sample: &df_project::scan::ProjectSample, rule_stack: &[String]) -> Vec<ChatMessage> {
    let system = "你是项目分析助手。根据给定的项目采样信息,分析并输出项目基础信息。\n\
严格只输出一个 JSON 对象,不要任何解释、markdown 代码块或额外文字。格式:\n\
{\"description\":\"一句话中文项目摘要,描述项目做什么,30-60字\",\"stack\":[\"技术栈标签(小写英文,如 vue/rust/go)\"],\"project_type\":\"web|api|cli|library|desktop|mobile|monorepo|other\"}\n\
规则:stack 用小写英文标签且去重;description 中文;project_type 从给定枚举选最接近的。若无足够信息,description 填空字符串。";
    let rule = if rule_stack.is_empty() { "(无)".to_string() } else { rule_stack.join(", ") };
    let tree = if sample.tree.is_empty() { "(无)".to_string() } else { sample.tree.join("\n") };
    let readme = sample.readme.clone().unwrap_or_else(|| "(无)".to_string());
    let manifests = if sample.manifests.is_empty() {
        "(无)".to_string()
    } else {
        sample.manifests.iter().map(|(n, c)| format!("### {n}\n{c}")).collect::<Vec<_>>().join("\n\n")
    };
    let user = format!(
        "## 已探测技术栈(规则)\n{rule}\n\n## 目录结构(2层)\n{tree}\n\n## README\n{readme}\n\n## 清单文件\n{manifests}"
    );
    vec![ChatMessage::system(system), ChatMessage::user(user)]
}

/// 解析 LLM 返回的 JSON(容错:直接解析失败则提取首个 {...} 再解析)
fn parse_scan_result(text: &str) -> Option<ParsedScan> {
    let extract = |v: &serde_json::Value| -> Option<ParsedScan> {
        let description = v.get("description").and_then(|x| x.as_str()).unwrap_or("").to_string();
        let stack = v
            .get("stack")
            .and_then(|x| x.as_array())
            .map(|arr| arr.iter().filter_map(|x| x.as_str().map(String::from)).collect())
            .unwrap_or_default();
        let project_type = v.get("project_type").and_then(|x| x.as_str()).map(String::from);
        Some(ParsedScan { description, stack, project_type })
    };
    if let Ok(v) = serde_json::from_str::<serde_json::Value>(text) {
        return extract(&v);
    }
    // 提取首个 {...}(LLM 可能裹 markdown 代码块或前后文字)
    let start = text.find('{')?;
    let end = text.rfind('}')?;
    if end <= start {
        return None;
    }
    let v = serde_json::from_str::<serde_json::Value>(&text[start..=end]).ok()?;
    extract(&v)
}