ID-list request & JSON parsing

.gitignore

@@ -1 +1,2 @@
 /target
+testdata.json

Cargo.toml

@@ -8,3 +8,6 @@ edition = "2021"
 [dependencies]
 clap = "3.1.18"
 regex = "1.5.6"
+reqwest = { version = "0.11", features = ["json"] }
+tokio = { version = "1.18.2", features = ["full"] }
+serde_json = "1.0"

src/main.rs

@@ -1,21 +1,25 @@
 use clap::{Arg, ArgGroup, Command};
 use regex::Regex;
+use serde_json::Value;
 use std::{path::PathBuf, process::exit};
 
+// General error type to make error handling easier
+type Result<T> = std::result::Result<T, Box<dyn std::error::Error>>;
+
 #[derive(Debug, PartialEq, Eq)]
 enum Mode {
     Thread,
     Board,
 }
 
-fn parse_cli_args() -> (PathBuf, String, Mode) {
-    let matches = Command::new("My Super Program")
-        .version("1.0")
-        .author("Kevin K. <kbknapp@gmail.com>")
-        .about("Does awesome things")
+fn parse_cli_args() -> Result<(PathBuf, String, Mode)> {
+    let matches = Command::new("WGDL-imagescraper written in Rust")
+        .version("0.1.0")
+        .author("Arttu Einistö <einisto@proton.me>")
+        .about("Scrapes images efficiently from 4chan.org")
         .arg(
-            Arg::new("path")
-                .short('p')
+            Arg::new("output")
+                .short('o')
                 .long("path")
                 .value_name("PATH")
                 .help("Set an output directory")
@@ -46,11 +50,10 @@ fn parse_cli_args() -> (PathBuf, String, Mode) {
         .get_matches();
 
     let re = Regex::new(
-        r"(http|https)://boards.(4chan|4channel).org/[a-zA-Z]{1,4}/(catalog|thread/\d+)",
-    )
-    .unwrap();
+        r"^((http|https)://)?boards.(4chan|4channel).org/[a-zA-Z]{1,4}/(catalog|thread/\d+)$",
+    )?;
 
-    let path = PathBuf::from(matches.value_of("path").unwrap());
+    let path = PathBuf::from(matches.value_of("output").unwrap());
     let target_match = matches.value_of("target").unwrap();
     let target = match re.is_match(target_match) {
         true => target_match,
@@ -64,15 +67,67 @@ fn parse_cli_args() -> (PathBuf, String, Mode) {
         false => Mode::Board,
     };
 
-    (path, String::from(target), mode)
+    Ok((path, String::from(target), mode))
 }
 
-fn main() {
-    // TODO: add var for default output path (similar to wgdl.py)
-    let (path, target, mode) = parse_cli_args();
+fn create_thread_url(target: String) -> String {
+    let url_vec: Vec<&str> = target.split("/").collect();
+    let thread_id = url_vec.get(url_vec.len() - 1).unwrap();
+    let board = url_vec.get(url_vec.len() - 3).unwrap();
+
+    format!("https://a.4cdn.org/{}/thread/{}.json", board, thread_id)
+}
+
+fn create_board_url(target: String) -> String {
+    let url_vec: Vec<&str> = target.split("/").collect();
+    let board = url_vec.get(url_vec.len()).unwrap();
+
+    format!("https://a.4cdn.org/{}/catalog.json", board)
+}
+
+async fn get_imagelist(json_url: &str) -> Result<Vec<(String, String)>> {
+    let req_body = reqwest::get(json_url).await?.text().await?;
+    let json_data: Value = serde_json::from_str(req_body.as_str())?;
+
+    let mut thread_img_data: Vec<(String, String)> = Vec::new();
+    for post in json_data["posts"].as_array().unwrap() {
+        if post["tim"].is_i64() {
+            thread_img_data.push((
+                post["tim"].to_string(),
+                post["ext"].as_str().unwrap().to_string(),
+            ));
+        } else {
+            continue;
+        }
+    }
+
+    Ok(thread_img_data)
+}
+
+#[tokio::main]
+async fn main() -> Result<()> {
+    // TODO: add possible config-file for default output path (similar to wgdl.py)
+    let (path, target, mode) = parse_cli_args()?;
 
     println!(
-        "CONFIG:\n\tPATH: {:?}\n\tTARGET: {}\n\tMODE: {:?}",
+        "\nCONFIG:\n\tPATH: {:?}\n\tTARGET: {}\n\tMODE: {:?}\n",
         path, target, mode
     );
+
+    match mode {
+        Mode::Thread => {
+            let json_url = create_thread_url(target);
+            let id_list = get_imagelist(&json_url.as_str()).await?;
+            println!("{:#?}", id_list);
+            // 3.) download img based on json
+        }
+        Mode::Board => {
+            let json_url = create_board_url(target);
+            let id_list = get_imagelist(&json_url.as_str()).await?;
+            println!("{:#?}", id_list);
+            // 3.) download img based on json
+        }
+    };
+
+    Ok(())
 }