feat: works

__crypto/simple_contract/src/credit.rs

@@ -1,7 +1,7 @@
 use std::{collections::HashMap, fs, fs::File};
-use rust_util::{SimpleError, XResult, simple_error};
+use rust_util::{XResult, information, simple_error};
 use serde::{Serialize, Deserialize};
-use crate::{tx::Transaction};
+use crate::tx::Transaction;
 
 #[derive(Debug, Serialize, Deserialize)]
 pub struct CreditContract {
@@ -18,9 +18,10 @@ impl CreditContract {
             name: name.into(),
             credit_limit,
             issue_amount: 0,
-            admin: tx.sender.clone().unwrap(),
+            admin: tx.sender.clone(),
             credit: HashMap::new(),
         };
+        save_credit_contract(&c, false)?;
         Ok(c)
     }
 
@@ -29,23 +30,29 @@ impl CreditContract {
     }
 
     pub fn issue(&mut self, tx: &Transaction, receiver: &str, credit: u32) -> XResult<()> {
-        if &self.admin != tx.sender.as_ref().ok_or_else(|| SimpleError::new("Sender is not provided".into()))? {
+        if &self.admin != &tx.sender {
             return simple_error!("Current user is not admin, {} vs {:?}", self.admin, tx.sender);
         }
+        if credit == 0 {
+            return simple_error!("Cannot issue 0 credit!");
+        }
         if self.issue_amount + credit > self.credit_limit {
-            return simple_error!("Issue too much credit, current: {}, issue: {}, limit: {}", self.issue_amount, credit, self.credit_limit);
+            return simple_error!("Issue too much credit, current: {}, issue: {}, limit: {}, left: {}", self.issue_amount, credit, self.credit_limit, self.credit_limit - self.issue_amount);
         }
         match self.credit.get_mut(receiver) {
             None => { self.credit.insert(receiver.to_owned(), credit); },
             Some(cr) => *cr += credit,
         }
         self.issue_amount += credit;
-        save_credit_contract(self)?;
+        save_credit_contract(self, true)?;
         Ok(())
     }
 
     pub fn transfer(&mut self, tx: &Transaction, receiver: &str, credit: u32) -> XResult<()> {
-        match self.credit.get_mut(tx.sender.as_ref().ok_or_else(|| SimpleError::new("Sender is not provided".into()))?) {
+        if credit == 0 {
+            return simple_error!("Cannot transfer 0 credit!");
+        }
+        match self.credit.get_mut(&tx.sender) {
             None => return simple_error!("Have not enough credit: {:?}", tx.sender),
             Some(cr) => {
                 if *cr >= credit {
@@ -59,7 +66,7 @@ impl CreditContract {
                 }
             },
         }
-        save_credit_contract(self)?;
+        save_credit_contract(self, true)?;
         Ok(())
     }
 
@@ -80,11 +87,14 @@ fn load_credit_contract(name: &str) -> XResult<CreditContract> {
     serde_json::from_str(&json).map_err(|e| e.into())
 }
 
-fn save_credit_contract(c: &CreditContract) -> XResult<()> {
+fn save_credit_contract(c: &CreditContract, overwrite: bool) -> XResult<()> {
     let name = &c.name;
-    if let Ok(_) = File::open(name) {
-        return simple_error!("File exists: {}", name);
+    if !overwrite {
+        if let Ok(_) = File::open(name) {
+            return simple_error!("File exists: {}", name);
+        }
     }
+    information!("Write file: {}", name);
     fs::write(name, serde_json::to_string(c)?.as_bytes())?;
     Ok(())
 }