forc 0.13.0

use crate::cli::InitCommand;
use crate::utils::{
    defaults,
    program_type::{ProgramType, ProgramType::*},
    SWAY_GIT_TAG,
};
use anyhow::{Context, Result};
use forc_util::{println_green, validate_name};
use serde::Deserialize;
use std::fs;
use std::fs::File;
use std::io::{Read, Write};
use std::path::{Path, PathBuf};
use sway_utils::constants;
use url::Url;

#[derive(Debug)]
struct GitPathInfo {
    owner: String,
    repo_name: String,
    example_name: String,
}

#[derive(Debug, Deserialize)]
#[serde(rename_all = "lowercase")]
enum FileType {
    File,
    Dir,
}

// Dead fields required for deserialization.
#[allow(dead_code)]
#[derive(serde::Deserialize, Debug)]
struct Links {
    git: String,
    html: String,
    #[serde(rename = "self")]
    cur: String,
}

// Dead fields required for deserialization.
#[allow(dead_code)]
#[derive(serde::Deserialize, Debug)]
struct ContentResponse {
    #[serde(rename = "_links")]
    links: Links,
    download_url: Option<String>,
    git_url: String,
    html_url: String,
    name: String,
    path: String,
    sha: String,
    size: u64,
    #[serde(rename = "type")]
    file_type: FileType,
    url: String,
}

#[allow(dead_code)]
#[derive(serde::Deserialize)]
struct GithubRepoResponse {
    sha: String,
    url: String,
    // We only care about the tree here
    tree: Vec<GithubTree>,
    truncated: bool,
}

#[allow(dead_code)]
#[derive(serde::Deserialize)]
struct GithubTree {
    mode: String,
    // We only care about the "path" which are files / directory names
    path: String,
    sha: String,
    size: Option<usize>,
    #[serde(rename = "type")]
    data_type: String,
    url: String,
}

fn print_welcome_message() {
    let read_the_docs = format!(
        "Read the Docs:\n- {}\n- {}\n- {}",
        "Sway Book: https://fuellabs.github.io/sway/latest",
        "Rust SDK Book: https://fuellabs.github.io/fuels-rs/latest",
        "TypeScript SDK: https://github.com/FuelLabs/fuels-ts"
    );

    let join_the_community = format!(
        "Join the Community:\n- Follow us {}
- Ask questions in dev-chat on {}",
        "@SwayLang: https://twitter.com/SwayLang", "Discord: https://discord.com/invite/xfpK4Pe"
    );

    let report_bugs = format!(
        "Report Bugs:\n- {}",
        "Sway Issues: https://github.com/FuelLabs/sway/issues/new"
    );

    let try_forc = "To compile, use `forc build`, and to run tests use `forc test`";

    println!(
        "\n{}\n\n----\n\n{}\n\n{}\n\n{}\n\n",
        try_forc, read_the_docs, join_the_community, report_bugs
    );
}

pub fn init(command: InitCommand) -> Result<()> {
    let project_name = command.project_name;
    validate_name(&project_name, "project name")?;

    match command.template {
        Some(template) => {
            let example_url =
                format!("https://github.com/FuelLabs/sway/tree/{SWAY_GIT_TAG}/examples/{template}");

            let template_url = Url::parse(&example_url)?;

            // If the user queried an existing example then continue otherwise attempt to fetch the examples and append them
            // to the end of the error message so that the user can see the existing examples to choose from
            match init_from_git_template(project_name, &template_url) {
                Ok(()) => Ok(()),
                Err(error) => {
                    let mut error_message = format!("Failed to initialize project from a template with the given name \"{template}\": {error}.\n  Note: If you are attempting to initialize this project from a Sway example, please ensure the template name matches one of the available examples.\n");

                    let examples = match get_sway_examples() {
                        Ok(examples) => examples,
                        Err(err) => anyhow::bail!(
                            "{}\nFailed to fetch available examples: {}",
                            error_message,
                            err
                        ),
                    };

                    for example in examples {
                        error_message.push_str(format!("\t- {}\n", example).as_str());
                    }

                    anyhow::bail!("{}", error_message)
                }
            }
        }
        None => {
            let program_type = match (
                command.contract,
                command.script,
                command.predicate,
                command.library,
            ) {
                (_, false, false, false) => Contract,
                (false, true, false, false) => Script,
                (false, false, true, false) => Predicate,
                (false, false, false, true) => Library,
                _ => anyhow::bail!(
                    "Multiple types detected, please specify only one program type: \
                \n Possible Types:\n - contract\n - script\n - predicate\n - library"
                ),
            };

            init_new_project(project_name, program_type)
        }
    }
}

fn get_sway_examples() -> Result<Vec<String>> {
    // Query the main repo so that we can search for the "sha" that belongs to "examples"
    let sway_response: GithubRepoResponse = ureq::get(
        format!("https://api.github.com/repos/FuelLabs/sway/git/trees/{SWAY_GIT_TAG}").as_str(),
    )
    .call()?
    .into_json()?;

    // Filter out the URL that contains the "sha" for the next request
    let examples_url = sway_response
        .tree
        .iter()
        .filter(|tree| tree.path == "examples")
        .map(|tree| tree.url.clone())
        .collect::<String>();

    // We want to store repo names of the "examples" that we have found
    let mut examples: Vec<String> = vec![];

    if !examples_url.is_empty() {
        let examples_response: GithubRepoResponse = ureq::get(&examples_url).call()?.into_json()?;

        // Filter out the repo names under "sway/examples"
        examples = examples_response
            .tree
            .iter()
            .map(|tree| tree.path.clone())
            .collect();
    };

    Ok(examples)
}

pub(crate) fn init_new_project(project_name: String, program_type: ProgramType) -> Result<()> {
    let neat_name: String = project_name.split('/').last().unwrap().to_string();

    // Make a new directory for the project
    fs::create_dir_all(Path::new(&project_name).join("src"))?;

    // Make directory for tests
    fs::create_dir_all(Path::new(&project_name).join("tests"))?;

    // Insert default manifest file
    match program_type {
        Library => fs::write(
            Path::new(&project_name).join(constants::MANIFEST_FILE_NAME),
            defaults::default_manifest(&neat_name, constants::LIB_ENTRY),
        )?,
        _ => fs::write(
            Path::new(&project_name).join(constants::MANIFEST_FILE_NAME),
            defaults::default_manifest(&neat_name, constants::MAIN_ENTRY),
        )?,
    }

    // Insert default test manifest file
    fs::write(
        Path::new(&project_name).join(constants::TEST_MANIFEST_FILE_NAME),
        defaults::default_tests_manifest(&neat_name),
    )?;

    // Insert src based on program_type
    match program_type {
        Contract => fs::write(
            Path::new(&project_name)
                .join("src")
                .join(constants::MAIN_ENTRY),
            defaults::default_contract(),
        )?,
        Script => fs::write(
            Path::new(&project_name)
                .join("src")
                .join(constants::MAIN_ENTRY),
            defaults::default_script(),
        )?,
        Library => fs::write(
            Path::new(&project_name)
                .join("src")
                .join(constants::LIB_ENTRY),
            defaults::default_library(&project_name),
        )?,
        Predicate => fs::write(
            Path::new(&project_name)
                .join("src")
                .join(constants::MAIN_ENTRY),
            defaults::default_predicate(),
        )?,
    }

    // Insert default test function
    fs::write(
        Path::new(&project_name).join("tests").join("harness.rs"),
        defaults::default_test_program(&project_name),
    )?;

    // Ignore default `out` and `target` directories created by forc and cargo.
    fs::write(
        Path::new(&project_name).join(".gitignore"),
        defaults::default_gitignore(),
    )?;

    println_green(&format!(
        "Successfully created {program_type}: {project_name}",
    ));

    print_welcome_message();

    Ok(())
}

pub(crate) fn init_from_git_template(project_name: String, example_url: &Url) -> Result<()> {
    let git = parse_github_link(example_url)?;

    let custom_url = format!(
        "https://api.github.com/repos/{}/{}/contents/{}",
        git.owner, git.repo_name, git.example_name
    );

    // Get the path of the example we are using
    let path = std::env::current_dir()?;
    let out_dir = path.join(&project_name);
    let real_name = whoami::realname();

    let responses: Vec<ContentResponse> = ureq::get(&custom_url).call()?.into_json()?;

    // Iterate through the responses to check that the link is a valid sway project
    // by checking for a Forc.toml file. Otherwise, return an error
    let valid_sway_project = responses
        .iter()
        .any(|response| response.name == "Forc.toml");
    if !valid_sway_project {
        anyhow::bail!(
            "The provided github URL: {} does not contain a Forc.toml file at the root",
            example_url
        );
    }

    // Download the files and directories from the github example
    download_contents(&custom_url, &out_dir, &responses)
        .with_context(|| format!("couldn't download from: {}", &custom_url))?;

    // Change the project name and authors of the Forc.toml file
    edit_forc_toml(&out_dir, &project_name, &real_name)?;

    // If the example has a tests folder, edit the Cargo.toml
    // Otherwise, create a basic tests template for the project
    if out_dir.join("tests").exists() {
        // Change the project name and authors of the Cargo.toml file
        edit_cargo_toml(&out_dir, &project_name, &real_name)?;
    } else {
        // Create the tests directory, harness.rs and Cargo.toml file
        fs::create_dir_all(out_dir.join("tests"))?;

        fs::write(
            out_dir.join("tests").join("harness.rs"),
            defaults::default_test_program(&project_name),
        )?;

        fs::write(
            out_dir.join("Cargo.toml"),
            defaults::default_tests_manifest(&project_name),
        )?;
    }

    println_green(&format!("Successfully created: {}", project_name));

    print_welcome_message();

    Ok(())
}

fn parse_github_link(url: &Url) -> Result<GitPathInfo> {
    let mut path_segments = url.path_segments().context("cannot be base")?;

    let owner_name = path_segments
        .next()
        .context("Cannot parse owner name from github URL")?;

    let repo_name = path_segments
        .next()
        .context("Cannot repository name from github URL")?;

    let example_name = match path_segments
        .skip(2)
        .map(|s| s.to_string())
        .reduce(|cur: String, nxt: String| format!("{}/{}", cur, nxt))
    {
        Some(example_name) => example_name,
        None => "".to_string(),
    };
    Ok(GitPathInfo {
        owner: owner_name.to_string(),
        repo_name: repo_name.to_string(),
        example_name,
    })
}

fn edit_forc_toml(out_dir: &Path, project_name: &str, real_name: &str) -> Result<()> {
    let mut file = File::open(out_dir.join(constants::MANIFEST_FILE_NAME))?;
    let mut toml = String::new();
    file.read_to_string(&mut toml)?;
    let mut manifest_toml = toml.parse::<toml_edit::Document>()?;

    let mut authors = Vec::new();
    let forc_toml: toml::Value = toml::de::from_str(&toml)?;
    if let Some(table) = forc_toml.as_table() {
        if let Some(package) = table.get("project") {
            // If authors Vec is currently populated use that
            if let Some(toml::Value::Array(authors_vec)) = package.get("authors") {
                for author in authors_vec {
                    if let toml::value::Value::String(name) = &author {
                        authors.push(name.clone());
                    }
                }
            }
        }
    }

    // Only append the users name to the authors field if it isn't already in the list
    if authors.iter().any(|e| e != real_name) {
        authors.push(real_name.to_string());
    }

    let authors: toml_edit::Array = authors.iter().collect();
    manifest_toml["project"]["authors"] = toml_edit::value(authors);
    manifest_toml["project"]["name"] = toml_edit::value(project_name);

    // Remove explicit std entry from copied template
    if let Some(project) = manifest_toml.get_mut("dependencies") {
        let _ = project
            .as_table_mut()
            .context("Unable to get forc manifest as table")?
            .remove("std");
    }

    let mut file = File::create(out_dir.join(constants::MANIFEST_FILE_NAME))?;
    file.write_all(manifest_toml.to_string().as_bytes())?;
    Ok(())
}

fn edit_cargo_toml(out_dir: &Path, project_name: &str, real_name: &str) -> Result<()> {
    let mut file = File::open(out_dir.join(constants::TEST_MANIFEST_FILE_NAME))?;
    let mut toml = String::new();
    file.read_to_string(&mut toml)?;

    let mut updated_authors = toml_edit::Array::default();

    let cargo_toml: toml::Value = toml::de::from_str(&toml)?;
    if let Some(table) = cargo_toml.as_table() {
        if let Some(package) = table.get("package") {
            if let Some(toml::Value::Array(authors_vec)) = package.get("authors") {
                for author in authors_vec {
                    if let toml::value::Value::String(name) = &author {
                        updated_authors.push(name);
                    }
                }
            }
        }
    }
    updated_authors.push(real_name);

    let mut manifest_toml = toml.parse::<toml_edit::Document>()?;
    manifest_toml["package"]["authors"] = toml_edit::value(updated_authors);
    manifest_toml["package"]["name"] = toml_edit::value(project_name);

    let mut file = File::create(out_dir.join(constants::TEST_MANIFEST_FILE_NAME))?;
    file.write_all(manifest_toml.to_string().as_bytes())?;
    Ok(())
}

fn download_file(url: &str, file_name: &str, out_dir: &Path) -> Result<PathBuf> {
    let mut data = Vec::new();
    let resp = ureq::get(url).call()?;
    resp.into_reader().read_to_end(&mut data)?;
    let path = out_dir.canonicalize()?.join(file_name);
    let mut file = File::create(&path)?;
    file.write_all(&data[..])?;
    Ok(path)
}

fn download_contents(url: &str, out_dir: &Path, responses: &[ContentResponse]) -> Result<()> {
    if !out_dir.exists() {
        fs::create_dir(out_dir)?;
    }

    // for all file_type == "file" responses, download the file and save it to the project directory.
    // for all file_type == "dir" responses, recursively call this function.
    for response in responses {
        match &response.file_type {
            FileType::File => {
                if let Some(url) = &response.download_url {
                    download_file(url, &response.name, out_dir)?;
                }
            }
            FileType::Dir => {
                match &response.name.as_str() {
                    // Test directory no longer exists, make sure to create this from scratch!!
                    // Only download the directory and its contents if it matches src or tests
                    &constants::SRC_DIR | &constants::TEST_DIRECTORY => {
                        let dir = out_dir.join(&response.name);
                        let url = format!("{}/{}", url, response.name);
                        let responses: Vec<ContentResponse> =
                            ureq::get(&url).call()?.into_json()?;
                        download_contents(&url, &dir, &responses)?;
                    }
                    _ => (),
                }
            }
        }
    }

    Ok(())
}

#[cfg(test)]
mod tests {
    use super::parse_github_link;
    use url::Url;

    #[test]
    fn test_github_link_parsing() {
        let example_url =
            Url::parse("https://github.com/FuelLabs/sway/tree/master/examples/hello_world")
                .unwrap();
        let git = parse_github_link(&example_url).unwrap();
        assert_eq!(git.owner, "FuelLabs");
        assert_eq!(git.repo_name, "sway");
        assert_eq!(git.example_name, "examples/hello_world");

        let example_url =
            Url::parse("https://github.com/FuelLabs/swayswap-demo/tree/master/contracts").unwrap();
        let git = parse_github_link(&example_url).unwrap();
        assert_eq!(git.owner, "FuelLabs");
        assert_eq!(git.repo_name, "swayswap-demo");
        assert_eq!(git.example_name, "contracts");
    }
}