use axum::{
    extract::Path,
    Json,
};
use serde::{Deserialize, Serialize};

use crate::models::{Account, TokenData, QuotaData};
use crate::modules;
use crate::error::AppError;

/// API response wrapper
#[derive(Serialize)]
pub struct ApiResponse<T> {
    pub success: bool,
    pub data: Option<T>,
    pub error: Option<String>,
}

impl<T: Serialize> ApiResponse<T> {
    pub fn success(data: T) -> Json<Self> {
        Json(Self {
            success: true,
            data: Some(data),
            error: None,
        })
    }

    pub fn error(message: String) -> Json<Self> {
        Json(Self {
            success: false,
            data: None,
            error: Some(message),
        })
    }
}

/// List all accounts
pub async fn list_accounts() -> Result<Json<ApiResponse<Vec<Account>>>, AppError> {
    let accounts = modules::list_accounts().map_err(AppError::Account)?;
    Ok(ApiResponse::success(accounts))
}

/// Add account request
#[derive(Deserialize)]
pub struct AddAccountRequest {
    pub email: String,
    pub refresh_token: String,
}

/// Add new account
pub async fn add_account(
    Json(req): Json<AddAccountRequest>,
) -> Result<Json<ApiResponse<Account>>, AppError> {
    modules::logger::log_info(&format!("Adding account: {}", req.email));

    // 1. Use refresh_token to get access_token
    let token_res = modules::oauth::refresh_access_token(&req.refresh_token)
        .await
        .map_err(AppError::OAuth)?;

    // 2. Get user info
    let user_info = modules::oauth::get_user_info(&token_res.access_token)
        .await
        .map_err(AppError::OAuth)?;

    // 3. Construct TokenData
    let token = TokenData::new(
        token_res.access_token,
        req.refresh_token,
        token_res.expires_in,
        Some(user_info.email.clone()),
        None,
        None,
    );

    // 4. Add or update account using real email
    let mut account = modules::upsert_account(
        user_info.email.clone(),
        user_info.get_display_name(),
        token,
    ).map_err(AppError::Account)?;

    modules::logger::log_info(&format!("Account added successfully: {}", account.email));

    // 5. Auto refresh quota
    let _ = internal_refresh_account_quota(&mut account).await;

    Ok(ApiResponse::success(account))
}

/// Delete account
pub async fn delete_account(
    Path(account_id): Path<String>,
) -> Result<Json<ApiResponse<()>>, AppError> {
    modules::logger::log_info(&format!("Deleting account: {}", account_id));
    modules::delete_account(&account_id).map_err(AppError::Account)?;
    modules::logger::log_info(&format!("Account deleted: {}", account_id));
    Ok(ApiResponse::success(()))
}

/// Refresh account quota
pub async fn refresh_quota(
    Path(account_id): Path<String>,
) -> Result<Json<ApiResponse<QuotaData>>, AppError> {
    modules::logger::log_info(&format!("Refreshing quota for: {}", account_id));

    let mut account = modules::load_account(&account_id).map_err(AppError::Account)?;
    let quota = modules::account::fetch_quota_with_retry(&mut account).await?;

    // Update account quota
    modules::update_account_quota(&account_id, quota.clone()).map_err(AppError::Account)?;

    Ok(ApiResponse::success(quota))
}

/// Refresh stats response
#[derive(Serialize)]
pub struct RefreshStats {
    total: usize,
    success: usize,
    failed: usize,
    details: Vec<String>,
}

/// Refresh all account quotas
pub async fn refresh_all_quotas() -> Result<Json<ApiResponse<RefreshStats>>, AppError> {
    modules::logger::log_info("Starting batch quota refresh for all accounts");
    let accounts = modules::list_accounts().map_err(AppError::Account)?;

    let mut success = 0;
    let mut failed = 0;
    let mut details = Vec::new();

    // Serial processing to ensure persistence safety
    for mut account in accounts {
        if let Some(ref q) = account.quota {
            if q.is_forbidden {
                modules::logger::log_info(&format!("Skipping {} (Forbidden)", account.email));
                continue;
            }
        }

        modules::logger::log_info(&format!("Processing {}", account.email));

        match modules::account::fetch_quota_with_retry(&mut account).await {
            Ok(quota) => {
                if let Err(e) = modules::update_account_quota(&account.id, quota) {
                    failed += 1;
                    let msg = format!("Account {}: Save quota failed - {}", account.email, e);
                    details.push(msg.clone());
                    modules::logger::log_error(&msg);
                } else {
                    success += 1;
                    modules::logger::log_info("Success");
                }
            },
            Err(e) => {
                failed += 1;
                let msg = format!("Account {}: Fetch quota failed - {}", account.email, e);
                details.push(msg.clone());
                modules::logger::log_error(&msg);
            }
        }
    }

    modules::logger::log_info(&format!("Batch refresh completed: {} success, {} failed", success, failed));
    Ok(ApiResponse::success(RefreshStats { total: success + failed, success, failed, details }))
}

/// Get current account
pub async fn get_current_account() -> Result<Json<ApiResponse<Option<Account>>>, AppError> {
    let account_id = modules::get_current_account_id().map_err(AppError::Account)?;

    if let Some(id) = account_id {
        let account = modules::load_account(&id).map_err(AppError::Account)?;
        Ok(ApiResponse::success(Some(account)))
    } else {
        Ok(ApiResponse::success(None))
    }
}

/// Set current account
pub async fn set_current_account(
    Path(account_id): Path<String>,
) -> Result<Json<ApiResponse<()>>, AppError> {
    modules::logger::log_info(&format!("Setting current account: {}", account_id));
    modules::set_current_account_id(&account_id).map_err(AppError::Account)?;
    Ok(ApiResponse::success(()))
}

/// Internal helper: auto refresh quota after adding account
async fn internal_refresh_account_quota(account: &mut Account) -> Result<QuotaData, String> {
    modules::logger::log_info(&format!("Auto refreshing quota: {}", account.email));

    match modules::account::fetch_quota_with_retry(account).await {
        Ok(quota) => {
            let _ = modules::update_account_quota(&account.id, quota.clone());
            Ok(quota)
        },
        Err(e) => {
            modules::logger::log_warn(&format!("Auto refresh quota failed ({}): {}", account.email, e));
            Err(e.to_string())
        }
    }
}