Documentation
#![allow(dead_code)]

use anyhow::{Context, Result};
use std::fs;
use std::path::PathBuf;
use std::process::Command;

pub const TEST_CARGO_TOML: &str = r#"
[package]
name = "gull_test_crate"
version = "0.1.0"
authors = ["Some Dude <dude@bro.io>"]
edition = "2018"

[dependencies]

[lib]
name = "test"
path = "lib.rs"

[workspace]
"#;

// Test utility/Abstraction over a temporary directory containing a test project.
// Given a name of the project it will create an empty directory under. (deleting anything that
// is in its place from potential previous runs)
//      /absolute/path/to/gull/gull/tmp
//
// And provide an API for creating/modifying files under this project directory.
#[derive(Debug)]
pub struct Project {
    root_dir: PathBuf,
}

impl Project {
    pub fn new(name: &str) -> Result<Self> {
        let gull_root_dir = PathBuf::from(
            std::env::var("CARGO_MANIFEST_DIR").expect("Can't get project root directory"),
        );

        let mut root_dir = gull_root_dir;
        root_dir.push("tmp");
        root_dir.push(name);
        // Make sure there's no ghost files in the tmp dir from previous runs
        fs::remove_dir_all(&root_dir).ok();

        Ok(Self { root_dir })
    }

    // Write provided content to a file under the given path.
    //  write_file("Cargo.toml", "[package]")?;
    //
    // Will write a file under `absolute/path/to/gull/gull/tmp/test_project_name/Cargo.toml`
    pub fn write_file(&self, path: &str, content: &str) -> Result<()> {
        fs::create_dir_all(&self.root_dir).context("can't create project root dir")?;
        let mut absolute_path = self.root_dir.clone();
        absolute_path.push(path);
        fs::write(&absolute_path, content)
            .with_context(|| format!("failed to write file `{}`", absolute_path.display()))?;
        Ok(())
    }

    // Write a deafult template for Cargo.toml file that should work for an average
    // empty rust projcet
    pub fn write_default_cargo_toml(&self) -> Result<()> {
        self.write_file("Cargo.toml", TEST_CARGO_TOML)?;
        Ok(())
    }

    pub fn run(&self, command: &str) -> Result<CommandOutput> {
        let mut split = command.split_whitespace();
        let command = split.next().context("command is empty")?;

        let mut cmd = Command::new(command);
        cmd.current_dir(&self.root_dir);

        for arg in split {
            cmd.arg(arg);
        }

        let output = cmd
            .output()
            .with_context(|| format!("Failed to get command's output. Command: `{}`", command))?;

        let stdout = String::from_utf8(output.stdout)?;
        let stderr = String::from_utf8(output.stderr)?;
        Ok(CommandOutput {
            command: command.to_string(),
            stdout,
            stderr,
            exit_code: output.status.code(),
            success: output.status.success(),
        })
    }

    // Given a path relative to this project's root, return an absolute path
    pub fn absolute_path(&self, path: &str) -> Result<String> {
        let mut absolute_path = self.root_dir.clone();
        absolute_path.push(path);
        Ok(absolute_path.display().to_string())
    }
}

pub struct CommandOutput {
    pub command: String,
    pub stdout: String,
    pub stderr: String,
    pub exit_code: Option<i32>,
    pub success: bool,
}

impl CommandOutput {
    pub fn assert_success(&self) -> Result<()> {
        if !self.success {
            anyhow::bail!(format!(
                "
            Expected command `{}` to exit successfully, but it didn't.

            EXIT_CODE: {:?}

            STDOUT: 
            VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV



            {}



            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

            STDERR:
            VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV
            


            {}



            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
            ",
                self.command, self.exit_code, self.stdout, self.stderr
            ))
        }
        Ok(())
    }
}