use crate::infrastructure::db::DbPool;
use crate::interfaces::http::api::RealtimeEvent;
use reqwest::Client;
use std::sync::Arc;
use tokio::sync::broadcast;
use tracing::{error, info, warn};
use uuid::Uuid;
use sqlx::Row;

pub struct SmsNotificationService {
    pool: DbPool,
    client: Client,
    frontend_url: String,
}

impl SmsNotificationService {
    pub fn new(pool: DbPool) -> Self {
        let frontend_url = std::env::var("FRONTEND_URL")
            .unwrap_or_else(|_| "https://rtix.app".to_string());
        Self {
            pool,
            client: Client::builder()
                .timeout(std::time::Duration::from_secs(10))
                .build()
                .unwrap(),
            frontend_url,
        }
    }

    pub async fn run(&self, mut rx: broadcast::Receiver<RealtimeEvent>) {
        info!("Sms/WhatsApp Notification Service started.");
        loop {
            match rx.recv().await {
                Ok(event) => {
                    let service = Arc::new(Self {
                        pool: self.pool.clone(),
                        client: self.client.clone(),
                        frontend_url: self.frontend_url.clone(),
                    });
                    tokio::spawn(async move {
                        if let Err(e) = service.process_event(event).await {
                            error!("Error processing notification: {:?}", e);
                        }
                    });
                }
                Err(broadcast::error::RecvError::Lagged(n)) => {
                    warn!("Notification Service lagged by {} events", n);
                }
                Err(broadcast::error::RecvError::Closed) => break,
            }
        }
    }

    async fn process_event(
        &self,
        event: RealtimeEvent,
    ) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
        match event {
            RealtimeEvent::NewOrder {
                transaction_id,
                merchant_id,
                amount,
                buyer_phone,
            } => {
                let msg = format!(
                    "Your Rtix order for ₹{:.2} has been placed. Pay or track here: {}/track/{}",
                    amount, self.frontend_url, transaction_id
                );
                self.send_sms(&buyer_phone, Some(&merchant_id), "SMS_ORDER_CREATED", &msg)
                    .await?;
            }
            RealtimeEvent::OrderStatusChanged {
                transaction_id,
                merchant_id,
                new_status,
            } => {
                // Fetch buyer phone number from the database using dynamic query
                let record = sqlx::query("SELECT buyer_phone FROM orders WHERE transaction_id = $1")
                    .bind(&transaction_id)
                    .fetch_optional(&self.pool)
                    .await?;

                if let Some(row) = record {
                    let buyer_phone: String = row.get("buyer_phone");
                    let msg = format!(
                        "Status Update: Your Rtix order {} is now {}. Track here: {}/track/{}",
                        transaction_id, new_status, self.frontend_url, transaction_id
                    );
                    self.send_sms(&buyer_phone, Some(&merchant_id), "SMS_STATUS_CHANGED", &msg)
                        .await?;
                }
            }
            RealtimeEvent::NewChatMessage {
                transaction_id,
                merchant_id,
                message,
            } => {
                // message is a JSON object matching ChatMessage struct
                let sender_type = message.get("sender_type").and_then(|v| v.as_str()).unwrap_or("");
                let content = message.get("content").and_then(|v| v.as_str()).unwrap_or("");

                if sender_type == "MERCHANT" {
                    // Notify buyer
                    let record = sqlx::query("SELECT buyer_phone FROM orders WHERE transaction_id = $1")
                        .bind(&transaction_id)
                        .fetch_optional(&self.pool)
                        .await?;

                    if let Some(row) = record {
                        let buyer_phone: String = row.get("buyer_phone");
                        let msg = format!(
                            "New message from Merchant: '{}'. Reply here: {}/track/{}",
                            content, self.frontend_url, transaction_id
                        );
                        self.send_sms(&buyer_phone, Some(&merchant_id), "SMS_CHAT_MESSAGE", &msg)
                            .await?;
                    }
                } else if sender_type == "BUYER" {
                    // Notify merchant via email/log
                    let record = sqlx::query("SELECT email FROM merchants WHERE merchant_id = $1")
                        .bind(&merchant_id)
                        .fetch_optional(&self.pool)
                        .await?;

                    if let Some(row) = record {
                        let email: String = row.get("email");
                        let msg = format!(
                            "New message from Buyer for order {}: '{}'. Reply in dashboard: {}/dashboard",
                            transaction_id, content, self.frontend_url
                        );
                        // Log this to the notifications table as an email notification
                        let log_id = Uuid::new_v4().to_string();
                        sqlx::query(
                            r#"INSERT INTO notification_log
                               (id, merchant_id, recipient_email, event_type, subject, status, provider_id)
                               VALUES ($1, $2, $3, $4, $5, $6, $7)"#,
                        )
                        .bind(&log_id)
                        .bind(&merchant_id)
                        .bind(&email)
                        .bind("EMAIL_CHAT_MESSAGE")
                        .bind(&msg)
                        .bind("SENT")
                        .bind("mock-email-provider")
                        .execute(&self.pool)
                        .await?;

                        info!(
                            recipient = %email,
                            "Email notification logged: {}", msg
                        );
                    }
                }
            }
            _ => {}
        }
        Ok(())
    }

    async fn send_sms(
        &self,
        phone_number: &str,
        merchant_id: Option<&str>,
        event_type: &str,
        message: &str,
    ) -> Result<(), sqlx::Error> {
        let mut plan = "FREE".to_string();
        if let Some(m_id) = merchant_id {
            if let Ok(Some(row)) = sqlx::query("SELECT plan FROM merchants WHERE merchant_id = $1")
                .bind(m_id)
                .fetch_optional(&self.pool)
                .await
            {
                plan = row.get("plan");
            }
        }

        if plan == "FREE" {
            let log_id = Uuid::new_v4().to_string();
            let formatted_phone = format!("sms:{}", phone_number);
            sqlx::query(
                r#"INSERT INTO notification_log
                   (id, merchant_id, recipient_email, event_type, subject, status, provider_id, error_message)
                   VALUES ($1, $2, $3, $4, $5, 'FAILED', $6, $7)"#,
            )
            .bind(&log_id)
            .bind(merchant_id)
            .bind(&formatted_phone)
            .bind(event_type)
            .bind(message)
            .bind("mock-sms-provider")
            .bind("SMS notifications are disabled on FREE plan. Upgrade to STARTER or PRO plan to enable SMS.")
            .execute(&self.pool)
            .await?;

            info!(
                recipient = phone_number,
                "SMS skipped (FREE plan): {}", message
            );
            return Ok(());
        }

        let account_sid = std::env::var("TWILIO_ACCOUNT_SID").ok();
        let auth_token = std::env::var("TWILIO_AUTH_TOKEN").ok();
        let from_number = std::env::var("TWILIO_FROM_NUMBER").ok();

        let mut provider_id = None;
        let mut status = "SENT";
        let mut error_message = None;

        if let (Some(sid), Some(token), Some(from)) = (account_sid, auth_token, from_number) {
            let url = format!(
                "https://api.twilio.com/2010-04-01/Accounts/{}/Messages.json",
                sid
            );

            let params = [
                ("To", phone_number),
                ("From", &from),
                ("Body", message),
            ];

            match self
                .client
                .post(&url)
                .basic_auth(&sid, Some(&token))
                .form(&params)
                .send()
                .await
            {
                Ok(resp) => {
                    let status_code = resp.status();
                    if status_code.is_success() {
                        #[derive(serde::Deserialize)]
                        struct TwilioResponse {
                            sid: String,
                        }
                        if let Ok(data) = resp.json::<TwilioResponse>().await {
                            provider_id = Some(data.sid);
                        } else {
                            provider_id = Some("twilio-unknown-sid".to_string());
                        }
                        info!(
                            recipient = phone_number,
                            event = event_type,
                            "SMS sent successfully via Twilio"
                        );
                    } else {
                        status = "FAILED";
                        let err_text = resp.text().await.unwrap_or_else(|_| "Unknown error".to_string());
                        error!(
                            recipient = phone_number,
                            status = %status_code,
                            "Twilio error response: {}", err_text
                        );
                        error_message = Some(err_text);
                    }
                }
                Err(e) => {
                    status = "FAILED";
                    let err_msg = e.to_string();
                    error!("HTTP request to Twilio failed: {}", err_msg);
                    error_message = Some(err_msg);
                }
            }
        } else {
            // Mock sending via external provider (Dry Run)
            info!(
                recipient = phone_number,
                event = event_type,
                "[DRY RUN] SMS notification: {}", message
            );
            provider_id = Some("mock-sms-provider".to_string());
        }

        let log_id = Uuid::new_v4().to_string();
        let formatted_phone = format!("sms:{}", phone_number);

        sqlx::query(
            r#"INSERT INTO notification_log
               (id, merchant_id, recipient_email, event_type, subject, status, provider_id, error_message)
               VALUES ($1, $2, $3, $4, $5, $6, $7, $8)"#,
        )
        .bind(&log_id)
        .bind(merchant_id)
        .bind(&formatted_phone)
        .bind(event_type)
        .bind(message)
        .bind(status)
        .bind(provider_id)
        .bind(error_message)
        .execute(&self.pool)
        .await?;

        Ok(())
    }
}