use std::fmt::Display;
use std::path::Path;
use std::process::exit;

use log::{debug, error, info, trace};
use reqwest::blocking::get;

use manifest::build::Build;
use pkgfile::PKGFile;

use crate::package::identifier::{PackageIdentifier, PackageLocator};
use crate::types::fetch::TryFetch;

pub mod identifier;
pub mod installer;
pub mod queue;

#[derive(Eq, PartialEq)]
pub struct Package {
    pub identifier: PackageIdentifier,
    pub pkgfile: PKGFile,
    is_installed: bool,
    is_indexed: bool,
}

impl Package {
    /// Create a new package from a package identifier and a package file.
    pub fn new(identifier: PackageIdentifier, pkgfile: PKGFile) -> Package {
        Package {
            identifier,
            pkgfile,
            is_installed: false,
            is_indexed: false,
        }
    }

    /// Get the package manifest.
    pub fn manifest(&self) -> manifest::Manifest {
        manifest::Manifest::try_from(self.pkgfile.manifest.clone()).unwrap()
    }

    /// Get package dependencies
    pub fn dependencies(&self) -> Vec<Package> {
        let mut dependencies = vec![];
        for dependency in self.manifest().dependencies {
            let pkglocate = if let Ok(pl) = PackageLocator::try_from(dependency.clone()) {
                trace!("parsed pl successfully...");
                pl
            } else {
                error!("Could not parse package locator: {:?} in dependencies.", &dependency);
                exit(1);
            };
            let pkg = match Package::try_fetch(PackageIdentifier::PackageLocator(pkglocate)) {
                Ok(p) => p,
                Err(e) => {
                    error!("Could not fetch dependency: {}", e);
                    exit(1);
                }
            };
            dependencies.push(pkg);
        }
        dependencies
    }

    pub fn build_dependencies(&self) -> Vec<Package> {
        let mut dependencies = vec![];
        for dependency in self
            .manifest()
            .build
            .unwrap_or(Build::default())
            .dependencies {
            let pkglocate = if let Ok(pl) = PackageLocator::try_from(dependency.clone()) {
                trace!("parsed pl successfully...");
                pl
            } else {
                error!("Could not parse package locator: {:?} in dependencies.", &dependency);
                exit(1);
            };
            let pkg = match Package::try_fetch(PackageIdentifier::PackageLocator(pkglocate)) {
                Ok(p) => p,
                Err(e) => {
                    error!("Could not fetch dependency: {}", e);
                    exit(1);
                }
            };
            dependencies.push(pkg);
        }
        dependencies
    }

    /// Install the package.
    pub fn install(&mut self, build: bool) -> Result<(), installer::errors::InstallError> {
        let manifest = self.manifest();
        let mut installer = installer::PackageInstaller::new(
            manifest.clone(),
            self.pkgfile.clone(),
            if build {
                info!("building package: {}...", if self.manifest().package.name.is_empty() {
                    self.identifier.to_string()
                } else {
                    self.manifest().package.name
                });
                installer::InstallType::Build
            } else {
                info!("using binary install for package: {}...", if self.manifest().package.name.is_empty() {
                    self.identifier.to_string()
                } else {
                    self.manifest().package.name
                });
                installer::InstallType::Bin
            },
        );
        match installer.install() {
            Ok(_) => {
                self.is_installed = true;
                Ok(())
            }
            Err(e) => Err(e),
        }
    }

    /// Check if the package is installed.
    pub fn is_installed(&self) -> bool {
        self.is_installed
    }

    /// Check if the package is indexed.
    pub fn is_indexed(&self) -> bool {
        self.is_indexed
    }

    /// Remove the package from the system.
    pub fn remove(&mut self) -> Result<(), ()> {
        unimplemented!();
    }
}

#[derive(Debug)]
pub enum FetchError {
    HTTPError(reqwest::Error),
    IOError(std::io::Error),
    ParseError,
}

impl Display for FetchError {
    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
        match self {
            FetchError::HTTPError(e) => write!(f, "HTTP Error: {}", e),
            FetchError::IOError(e) => write!(f, "IO Error: {}", e),
            FetchError::ParseError => write!(f, "Parse Error"),
        }
    }
}

impl TryFetch<PackageIdentifier> for Package {
    type Error = FetchError;

    /// Fetch a package from a package identifier.
    fn try_fetch(query: PackageIdentifier) -> Result<Package, Self::Error> {
        trace!("Fetching: {query:#?}");
        let pkgfile = match &query {
            PackageIdentifier::Path(s) => match PKGFile::try_from(Path::new(&s)) {
                Ok(p) => Ok(p),
                Err(e) => Err(FetchError::ParseError)
            },
            PackageIdentifier::URI(s) => {
                let mut bytes = Vec::new();
                debug!("sending GET request...");
                match get::<String>(s.into()) {
                    Ok(response) => {
                        debug!("Got response!");
                        if let Ok(b) = response.bytes() {
                            bytes.extend(b);
                        }
                    }
                    Err(e) => return Err(FetchError::HTTPError(e)),
                };
                // parse bytes as PKGFile
                match PKGFile::try_from(bytes) {
                    Ok(pkgfile) => Ok(pkgfile),
                    Err(_e) => Err(FetchError::ParseError),
                }
            }
            PackageIdentifier::PackageLocator(l) => unimplemented!()
        };

        pkgfile
            .map(|p| Package::new(query, p))
    }
}