#![allow(dead_code)]

use semver::VersionReq;

use crate::errors::JsonError;
use url::Url;
use serde::Deserialize;
use std::{
    collections::HashMap,
    path::{
        PathBuf,
        Path
    },
    fs
};
use mlua::prelude::{
    LuaResult,
    LuaError
};


#[derive(Deserialize, Debug)]
pub struct Manifest {
    #[serde(skip, default = "default_url")]
    pub url: Url,
    pub plugins: Vec<Plugin>,
    pub repos: Option<Vec<String>>
}

#[derive(Deserialize, Debug)]
pub struct PluginReference {
    pub optional: Option<bool>,
    pub version: Option<VersionReq>
}

#[derive(Deserialize, Debug)]
struct File {
    pub url: Url,
    pub checksum: String,
    pub arch: String,
    pub path: PathBuf
}

#[derive(Deserialize, Debug)]
pub struct Plugin {
    pub name: String,
    pub description: String,
    pub version: VersionReq,
    pub mod_version: Option<String>,
    pub provides: Option<Vec<String>>,
    pub dependencies: Option<HashMap<String, PluginReference>>,
    pub conflicts: Option<HashMap<String, PluginReference>>,
    pub path: Option<PathBuf>,
    pub remote: Option<String>,
    pub url: Option<Url>,
    pub checksum: Option<String>,
}

fn default_url() -> Url {
    Url::parse("https://example.com").unwrap()
}

impl Manifest {
    pub fn parse<P>(path: P, url: Url) -> LuaResult<Manifest>
    where
        P: AsRef<Path>
    {
        let data = fs::read(path)?;

        let mut manifest: Manifest = serde_json::from_slice(data.as_slice()).map_err(JsonError)?;

        (&mut manifest).url = url;

        // Make sure that a plugin doesn't contain both 'url'/'checksum' and 'remote'
        for p in manifest.plugins.iter() {
            if p.url.is_some() && p.checksum.is_none() {
                return Err(LuaError::external(format!("Could not parse manifest from {}!\nField 'url' depends on field 'checksum'", manifest.url)));
            } else if p.url.is_none() && p.checksum.is_some() {
                return Err(LuaError::external(format!("Could not parse manifest from {}!\nField 'checksum' depends on field 'url'", manifest.url)));
            };
        
            if p.remote.is_some() && p.url.is_some() {
                return Err(LuaError::external(format!("Could not parse manifest from {}!\nConflicting fields 'remote' and 'url'", manifest.url)));
            }
        }

        Ok(manifest)
    }
}