// Copyright 2019 Glenn Mohre.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
use crate::{error::Error, package::Package};
use std::{fs::File, io::Read, path::Path};
use toml;

// Parsed Cargo.lock file containing dependencies
#[derive(Clone, Debug, Deserialize, Eq, PartialEq)]
pub struct Lockfile {
    // Dependencies enumerated in the lockfile
    #[serde(rename = "package")]
    pub packages: Vec<Package>,
}

impl Lockfile {
    // Load lock data from a `Cargo.lock` file
    pub fn load<P: AsRef<Path>>(path: P) -> Result<Self, Error> {
        let mut file = File::open(path.as_ref())?;
        let mut toml = String::new();
        file.read_to_string(&mut toml)?;
        Self::from_toml(&toml)
    }

    // Parse the TOML data from the `Cargo.lock` file
    pub fn from_toml(toml_string: &str) -> Result<Self, Error> {
        Ok(toml::from_str(toml_string)?)
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn load_cargo_lockfile() {
        let lockfile = Lockfile::load("Cargo.lock").unwrap();
        assert!(lockfile.packages.len() > 0);
    }

    #[test]
    #[should_panic(expected = "No such file or directory (os error 2)")]
    fn load_cargo_lockfile_nonexistant() {
        Lockfile::load("nosuchfile.notexist").unwrap();
    }

    #[test]
    #[should_panic(expected = "unexpected character found: `<` at line 1")]
    fn load_cargo_lockfile_invalid() {
        Lockfile::load("README.md").unwrap();
    }
}