use super::super::domain::{
	CreatePaymentCommand, PaymentEntity, PaymentRepository, PaymentService, SERVICE_FEE,
};
use crate::sessions::domain::SessionRepository;
use async_trait::async_trait;
use chrono::{Duration, Utc};
use imphnen_entities::seaorm::auth::mentors::Entity as MentorsEntity;
use imphnen_entities::seaorm::auth::users::Entity as UsersEntity;
use imphnen_utils::AppError;
use sea_orm::prelude::*;
use std::sync::Arc;
use uuid::Uuid;

pub struct PaymentServiceImpl {
	payment_repo: Arc<dyn PaymentRepository>,
	session_repo: Arc<dyn SessionRepository>,
	db: Arc<DatabaseConnection>,
}

impl PaymentServiceImpl {
	pub fn new(
		payment_repo: Arc<dyn PaymentRepository>,
		session_repo: Arc<dyn SessionRepository>,
		db: Arc<DatabaseConnection>,
	) -> Self {
		Self {
			payment_repo,
			session_repo,
			db,
		}
	}
}

fn generate_external_ref(method: &str, session_id: Uuid) -> String {
	match method {
		"va" => format!("VA-{}-{}", session_id.to_string().split('-').next().unwrap_or("X"), Utc::now().format("%Y%m%d%H%M%S")),
		"qris" => format!("QR-{}", session_id.to_string().replace('-', "").chars().take(16).collect::<String>()),
		_ => format!("MANUAL-{}", Utc::now().format("%Y%m%d%H%M%S")),
	}
}

#[async_trait]
impl PaymentService for PaymentServiceImpl {
	async fn create_payment(
		&self,
		session_id: Uuid,
		mentee_id: Uuid,
		cmd: CreatePaymentCommand,
	) -> Result<PaymentEntity, AppError> {
		// Only a valid session can be paid for.
		let session = self
			.session_repo
			.find_by_id(session_id)
			.await
			.map_err(|_| AppError::NotFoundError("Session not found".into()))?
			.ok_or_else(|| AppError::NotFoundError("Session not found".into()))?;

		// The mentee paying must be the session's mentee.
		if session.mentee_id != mentee_id {
			return Err(AppError::ForbiddenError(
				"You can only pay for your own sessions".into(),
			));
		}

		// Load mentor rate from the mentors table (mentors.user_id = the session's
		// mentor user id).
		let mentor_uuid = session.mentor_id;
		let mentor = MentorsEntity::find()
			.filter(imphnen_entities::seaorm::auth::mentors::Column::UserId.eq(mentor_uuid))
			.one(self.db.as_ref())
			.await
			.map_err(|e| AppError::InternalServerError(e.to_string()))?
			.ok_or_else(|| AppError::NotFoundError("Mentor not found".into()))?;

		let rate = mentor.mentoring_rate.unwrap_or(50_000.0).round() as i64;
		let total = rate + SERVICE_FEE;
		let method = cmd.method.clone();
		let provider = "manual".to_string(); // swap to midtrans/xendit later
		let expires_at = Utc::now() + Duration::hours(24);

		let payment = PaymentEntity {
			id: Uuid::new_v4(),
			session_id,
			mentee_id,
			mentor_id: mentor_uuid,
			amount: rate,
			service_fee: SERVICE_FEE,
			total,
			method: method.clone(),
			provider,
			status: "pending".into(),
			external_ref: Some(generate_external_ref(&method, session_id)),
			expires_at,
			created_at: Utc::now(),
			paid_at: None,
		};
		self.payment_repo.create(payment).await
	}

	async fn get_payment_by_id(
		&self,
		id: Uuid,
		user_id: Uuid,
	) -> Result<PaymentEntity, AppError> {
		let payment = self.payment_repo.find_by_id(id).await?;
		if payment.mentee_id != user_id {
			return Err(AppError::ForbiddenError(
				"You can only view your own payments".into(),
			));
		}
		Ok(payment)
	}

	async fn confirm_payment(
		&self,
		id: Uuid,
		actor_id: Uuid,
	) -> Result<PaymentEntity, AppError> {
		// Admin / "Admin Pembayaran" only — check role via users table.
		let user = UsersEntity::find_by_id(actor_id)
			.one(self.db.as_ref())
			.await
			.map_err(|e| AppError::InternalServerError(e.to_string()))?
			.ok_or_else(|| AppError::NotFoundError("Actor not found".into()))?;
		let role_id = user.role_id.ok_or_else(|| {
			AppError::ForbiddenError("User has no role assigned".into())
		})?;
		let roles = imphnen_entities::seaorm::auth::roles::Entity::find_by_id(role_id)
			.one(self.db.as_ref())
			.await
			.map_err(|e| AppError::InternalServerError(e.to_string()))?
			.ok_or_else(|| AppError::ForbiddenError("Role not found".into()))?;
		if roles.name != "Admin" && roles.name != "Admin Pembayaran" {
			return Err(AppError::ForbiddenError(
				"Only payment admin can confirm payments".into(),
			));
		}

		let payment = self.payment_repo.find_by_id(id).await?;
		if payment.status != "pending" {
			return Err(AppError::ConflictError(
				"Payment is not pending".into(),
			));
		}
		self.payment_repo
			.update_status(id, "paid", Some(payment.external_ref.clone().unwrap_or_default()))
			.await
	}

	async fn get_mentee_payments(
		&self,
		mentee_id: Uuid,
	) -> Result<Vec<PaymentEntity>, AppError> {
		self.payment_repo.find_by_mentee(mentee_id).await
	}
}