use std::iter::zip;
use anyhow::{Result, bail};
use serde::{Deserialize, Serialize};
use serde_json::Value as JsonValue;
#[derive(Debug, Deserialize)]
pub struct CsvWrapper {
pub items: serde_json::Value,
}
impl Serialize for CsvWrapper {
fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
where
S: serde::Serializer,
{
self.items.serialize(serializer)
}
}
pub fn load_csv(csv_bytes: &[u8]) -> Result<CsvWrapper> {
let mut reader = csv::Reader::from_reader(csv_bytes);
let header: Vec<String> = match reader.headers() {
Ok(headers) => headers.iter().map(|s| s.to_string()).collect(),
Err(e) => return Result::Err(e.into()),
};
let mut items = Vec::new();
for record_result in reader.records() {
let mut record_map = serde_json::Map::new();
for (key, value) in zip(header.clone(), &record_result?) {
record_map.insert(key, parse_value(value.trim()));
}
items.push(serde_json::Value::Object(record_map));
}
Ok(CsvWrapper {
items: serde_json::Value::Array(items),
})
}
fn parse_value(s: &str) -> JsonValue {
if s.is_empty() {
return JsonValue::Null;
}
if let Ok(b) = s.parse::<bool>() {
return JsonValue::Bool(b);
}
if let Ok(i) = s.parse::<i64>() {
return JsonValue::Number(i.into());
}
if let Ok(f) = s.parse::<f64>()
&& f.is_finite()
{
return JsonValue::Number(serde_json::Number::from_f64(f).unwrap());
}
JsonValue::String(s.to_string())
}
pub fn json_to_csv(json: &[u8]) -> Result<Vec<u8>> {
let json: JsonValue = serde_json::from_slice(json)?;
if let JsonValue::Array(values) = json {
let mut buffer = String::new();
let mut dump_header: bool = true;
for item in values {
if let JsonValue::Object(items) = item {
let keys: Vec<String> = items.keys().cloned().collect();
if dump_header {
dump_header = false;
let mut first = true;
for key in keys.clone() {
if first {
first = false;
} else {
buffer.push(',');
}
buffer.push_str(&key.to_string());
}
buffer.push('\n');
}
let mut first = true;
for key in keys {
if let Some(value) = items.get(&key) {
if first {
first = false;
} else {
buffer.push(',');
}
buffer.push_str(&value.to_string());
} else {
bail!("Missing value for key: in {key:?}")
}
}
} else {
bail!("Invalid json format for csv convertation: {item:?}")
}
buffer.push('\n');
}
Ok(buffer.into_bytes())
} else {
bail!("Invalid json format for csv convertation. Expected root Array of items.")
}
}