//! 项目 Profile 编排服务
//!
//! Profile 是一份按 app 的配置快照（供应商 / MCP / Skills / Prompt），
//! 应用（apply）时复用现有切换原语批量落地：
//! - 供应商：`ProviderService::switch`（内建代理接管热切换与接管下禁切官方）
//! - MCP：`McpService::toggle_app`（改标志 + 单 server 物化）
//! - Skills：`SkillService::toggle_app`（改标志 + 单 skill 物化）
//! - Prompt：`PromptService::enable_prompt`（互斥激活 + 原子写 live）
//!
//! apply 为 best-effort：单项失败收集为 warning 继续，不整体回滚。

use std::collections::HashSet;

use serde::{Deserialize, Serialize};

use crate::app_config::AppType;
use crate::database::Profile;
use crate::error::AppError;
use crate::services::{McpService, PromptService, ProviderService, SkillService};
use crate::store::AppState;

/// P1 支持的应用范围（扩展新 app 时同步扩展 PerApp 字段）
pub const PROFILE_APPS: [AppType; 2] = [AppType::Claude, AppType::Codex];

/// 按 app 分槽的载荷容器；字段名与 AppType 的 serde 小写形式一致
#[derive(Debug, Clone, Default, PartialEq, Serialize, Deserialize)]
#[serde(default)]
pub struct PerApp<T> {
    pub claude: T,
    pub codex: T,
}

impl<T> PerApp<T> {
    pub fn get(&self, app: &AppType) -> Option<&T> {
        match app {
            AppType::Claude => Some(&self.claude),
            AppType::Codex => Some(&self.codex),
            _ => None,
        }
    }

    pub fn get_mut(&mut self, app: &AppType) -> Option<&mut T> {
        match app {
            AppType::Claude => Some(&mut self.claude),
            AppType::Codex => Some(&mut self.codex),
            _ => None,
        }
    }
}

/// Profile 的 JSON 快照结构（与前端 TS 类型严格对应）
#[derive(Debug, Clone, Default, PartialEq, Serialize, Deserialize)]
#[serde(default)]
pub struct ProfilePayload {
    /// 每 app 的当前供应商 id（None = 快照时无当前供应商，应用时不动）
    pub providers: PerApp<Option<String>>,
    /// 每 app 启用的 MCP server id 集合
    pub mcp: PerApp<Vec<String>>,
    /// 每 app 启用的 Skill id 集合
    pub skills: PerApp<Vec<String>>,
    /// 每 app 激活的 prompt id（None = 快照时无激活项，应用时不动）
    pub prompts: PerApp<Option<String>>,
}

/// 计算从当前启用状态到目标集合的最小 toggle 集
///
/// 返回 (需要执行的 (id, enabled) 列表, payload 中已不存在于 DB 的悬空 id 列表)
fn plan_toggles(
    current: &[(String, bool)],
    target_ids: &[String],
) -> (Vec<(String, bool)>, Vec<String>) {
    let existing: HashSet<&str> = current.iter().map(|(id, _)| id.as_str()).collect();
    let target: HashSet<&str> = target_ids.iter().map(|s| s.as_str()).collect();

    let toggles = current
        .iter()
        .filter(|(id, enabled)| target.contains(id.as_str()) != *enabled)
        .map(|(id, enabled)| (id.clone(), !enabled))
        .collect();

    let dangling = target_ids
        .iter()
        .filter(|id| !existing.contains(id.as_str()))
        .cloned()
        .collect();

    (toggles, dangling)
}

pub struct ProfileService;

impl ProfileService {
    /// 抓取当前配置状态生成快照
    pub fn snapshot_current(state: &AppState) -> Result<ProfilePayload, AppError> {
        let mut payload = ProfilePayload::default();
        let mcp_servers = state.db.get_all_mcp_servers()?;
        let skills = state.db.get_all_installed_skills()?;

        for app in PROFILE_APPS.iter() {
            if let Some(slot) = payload.providers.get_mut(app) {
                *slot = crate::settings::get_effective_current_provider(&state.db, app)?;
            }
            if let Some(slot) = payload.mcp.get_mut(app) {
                *slot = mcp_servers
                    .values()
                    .filter(|s| s.apps.is_enabled_for(app))
                    .map(|s| s.id.clone())
                    .collect();
            }
            if let Some(slot) = payload.skills.get_mut(app) {
                *slot = skills
                    .values()
                    .filter(|s| s.apps.is_enabled_for(app))
                    .map(|s| s.id.clone())
                    .collect();
            }
            if let Some(slot) = payload.prompts.get_mut(app) {
                *slot = state
                    .db
                    .get_prompts(app.as_str())?
                    .values()
                    .find(|p| p.enabled)
                    .map(|p| p.id.clone());
            }
        }
        Ok(payload)
    }

    /// 列出所有项目及当前激活项目 id
    pub fn list(state: &AppState) -> Result<(Vec<Profile>, Option<String>), AppError> {
        let profiles = state.db.get_all_profiles()?;
        let current = state.db.get_current_profile_id()?;
        Ok((profiles, current))
    }

    /// 以当前配置状态创建新项目
    pub fn create(state: &AppState, name: &str) -> Result<Profile, AppError> {
        let name = name.trim();
        if name.is_empty() {
            return Err(AppError::InvalidInput("Profile name is empty".to_string()));
        }
        let payload = Self::snapshot_current(state)?;
        let now = chrono::Utc::now().timestamp();
        let profile = Profile {
            id: uuid::Uuid::new_v4().to_string(),
            name: name.to_string(),
            payload: serde_json::to_string(&payload)
                .map_err(|e| AppError::Config(format!("序列化 profile payload 失败: {e}")))?,
            sort_order: None,
            created_at: Some(now),
            updated_at: Some(now),
        };
        state.db.save_profile(&profile)?;
        Ok(profile)
    }

    /// 更新项目：重命名和/或以当前状态重拍快照
    pub fn update(
        state: &AppState,
        id: &str,
        name: Option<String>,
        resnapshot: bool,
    ) -> Result<Profile, AppError> {
        let mut profile = state
            .db
            .get_profile(id)?
            .ok_or_else(|| AppError::InvalidInput(format!("Profile not found: {id}")))?;

        if let Some(name) = name {
            let name = name.trim().to_string();
            if name.is_empty() {
                return Err(AppError::InvalidInput("Profile name is empty".to_string()));
            }
            profile.name = name;
        }
        if resnapshot {
            let payload = Self::snapshot_current(state)?;
            profile.payload = serde_json::to_string(&payload)
                .map_err(|e| AppError::Config(format!("序列化 profile payload 失败: {e}")))?;
        }
        profile.updated_at = Some(chrono::Utc::now().timestamp());
        state.db.save_profile(&profile)?;
        Ok(profile)
    }

    /// 删除项目；若删除的是当前激活项目，一并清除激活标记
    pub fn delete(state: &AppState, id: &str) -> Result<(), AppError> {
        state.db.delete_profile(id)?;
        if state.db.get_current_profile_id()?.as_deref() == Some(id) {
            state.db.set_current_profile_id(None)?;
        }
        Ok(())
    }

    /// 应用项目快照（best-effort，返回 warnings）
    ///
    /// 顺序不可换：供应商切换（switch_normal 内部会按 DB 当前标志跑 MCP
    /// sync_all_enabled）必须先于 MCP diff，否则 profile 的 MCP 目标态会被冲掉。
    pub fn apply(state: &AppState, profile_id: &str) -> Result<Vec<String>, AppError> {
        let profile = state
            .db
            .get_profile(profile_id)?
            .ok_or_else(|| AppError::InvalidInput(format!("Profile not found: {profile_id}")))?;
        let payload: ProfilePayload = serde_json::from_str(&profile.payload)
            .map_err(|e| AppError::Config(format!("解析 profile payload 失败: {e}")))?;

        let mut warnings = Vec::new();

        for app in PROFILE_APPS.iter() {
            let app_str = app.as_str();

            // 1. 供应商
            if let Some(Some(target_pid)) = payload.providers.get(app) {
                let providers = state.db.get_all_providers(app_str)?;
                if !providers.contains_key(target_pid) {
                    warnings.push(format!(
                        "[{app_str}] provider '{target_pid}' no longer exists, skipped"
                    ));
                } else {
                    let current = crate::settings::get_effective_current_provider(&state.db, app)?;
                    if current.as_deref() != Some(target_pid.as_str()) {
                        match ProviderService::switch(state, app.clone(), target_pid) {
                            Ok(result) => warnings.extend(result.warnings),
                            Err(e) => warnings.push(format!(
                                "[{app_str}] switch provider '{target_pid}' failed: {e}"
                            )),
                        }
                    }
                }
            }

            // 2. MCP diff（最小 toggle：仅动目标态≠当前态的条目）
            if let Some(target_ids) = payload.mcp.get(app) {
                let servers = state.db.get_all_mcp_servers()?;
                let current: Vec<(String, bool)> = servers
                    .values()
                    .map(|s| (s.id.clone(), s.apps.is_enabled_for(app)))
                    .collect();
                let (toggles, dangling) = plan_toggles(&current, target_ids);
                for id in dangling {
                    warnings.push(format!("[{app_str}] MCP '{id}' no longer exists, skipped"));
                }
                for (id, enabled) in toggles {
                    if let Err(e) = McpService::toggle_app(state, &id, app.clone(), enabled) {
                        warnings.push(format!(
                            "[{app_str}] toggle MCP '{id}' -> {enabled} failed: {e}"
                        ));
                    }
                }
            }

            // 3. Skills diff（SkillService 返回 anyhow::Result，收进 warning）
            if let Some(target_ids) = payload.skills.get(app) {
                let skills = state.db.get_all_installed_skills()?;
                let current: Vec<(String, bool)> = skills
                    .values()
                    .map(|s| (s.id.clone(), s.apps.is_enabled_for(app)))
                    .collect();
                let (toggles, dangling) = plan_toggles(&current, target_ids);
                for id in dangling {
                    warnings.push(format!(
                        "[{app_str}] skill '{id}' no longer exists, skipped"
                    ));
                }
                for (id, enabled) in toggles {
                    if let Err(e) = SkillService::toggle_app(&state.db, &id, app, enabled) {
                        warnings.push(format!(
                            "[{app_str}] toggle skill '{id}' -> {enabled} failed: {e}"
                        ));
                    }
                }
            }

            // 4. Prompt（None = 不动；已激活则幂等跳过，避免无谓的文件写与备份）
            if let Some(Some(target_prompt)) = payload.prompts.get(app) {
                let prompts = state.db.get_prompts(app_str)?;
                match prompts.get(target_prompt) {
                    None => warnings.push(format!(
                        "[{app_str}] prompt '{target_prompt}' no longer exists, skipped"
                    )),
                    Some(p) if p.enabled => {}
                    Some(_) => {
                        if let Err(e) =
                            PromptService::enable_prompt(state, app.clone(), target_prompt)
                        {
                            warnings.push(format!(
                                "[{app_str}] enable prompt '{target_prompt}' failed: {e}"
                            ));
                        }
                    }
                }
            }
        }

        state.db.set_current_profile_id(Some(profile_id))?;
        Ok(warnings)
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    fn ids(v: &[&str]) -> Vec<String> {
        v.iter().map(|s| s.to_string()).collect()
    }

    #[test]
    fn test_payload_serde_roundtrip() {
        let payload = ProfilePayload {
            providers: PerApp {
                claude: Some("p1".into()),
                codex: None,
            },
            mcp: PerApp {
                claude: ids(&["m1", "m2"]),
                codex: vec![],
            },
            skills: PerApp {
                claude: vec![],
                codex: ids(&["s1"]),
            },
            prompts: PerApp {
                claude: None,
                codex: Some("pr1".into()),
            },
        };
        let json = serde_json::to_string(&payload).unwrap();
        // per-app key 必须是 AppType serde 的小写形式
        assert!(json.contains("\"claude\""));
        assert!(json.contains("\"codex\""));
        let back: ProfilePayload = serde_json::from_str(&json).unwrap();
        assert_eq!(back, payload);
    }

    #[test]
    fn test_payload_tolerates_missing_fields() {
        // 前向兼容：旧版/部分字段缺失时应落到默认值而不是报错
        let back: ProfilePayload =
            serde_json::from_str(r#"{"providers":{"claude":"p1"}}"#).unwrap();
        assert_eq!(back.providers.claude, Some("p1".to_string()));
        assert_eq!(back.providers.codex, None);
        assert!(back.mcp.claude.is_empty());
        assert_eq!(back.prompts.codex, None);

        let empty: ProfilePayload = serde_json::from_str("{}").unwrap();
        assert_eq!(empty, ProfilePayload::default());
    }

    #[test]
    fn test_per_app_get_only_supports_profile_apps() {
        let per: PerApp<Option<String>> = PerApp::default();
        assert!(per.get(&AppType::Claude).is_some());
        assert!(per.get(&AppType::Codex).is_some());
        assert!(per.get(&AppType::Gemini).is_none());
        assert!(per.get(&AppType::ClaudeDesktop).is_none());
    }

    #[test]
    fn test_plan_toggles_minimal_diff() {
        let current = vec![
            ("a".to_string(), true),  // 目标含 a：不动
            ("b".to_string(), false), // 目标含 b：开
            ("c".to_string(), true),  // 目标不含 c：关
            ("d".to_string(), false), // 目标不含 d：不动
        ];
        let (toggles, dangling) = plan_toggles(&current, &ids(&["a", "b", "ghost"]));
        assert_eq!(
            toggles,
            vec![("b".to_string(), true), ("c".to_string(), false)]
        );
        assert_eq!(dangling, ids(&["ghost"]));
    }

    #[test]
    fn test_plan_toggles_empty_target_disables_all_enabled() {
        let current = vec![("a".to_string(), true), ("b".to_string(), false)];
        let (toggles, dangling) = plan_toggles(&current, &[]);
        assert_eq!(toggles, vec![("a".to_string(), false)]);
        assert!(dangling.is_empty());
    }
}