// rocie - An enterprise grocery management system
//
// Copyright (C) 2025 Benedikt Peetz <benedikt.peetz@b-peetz.de>
// Copyright (C) 2026 Benedikt Peetz <benedikt.peetz@b-peetz.de>
// SPDX-License-Identifier: GPL-3.0-or-later
//
// This file is part of Rocie.
//
// You should have received a copy of the License along with this program.
// If not, see <https://www.gnu.org/licenses/gpl-3.0.txt>.

use std::{
    env,
    ffi::OsStr,
    fmt::Write,
    fs,
    io::{self, BufRead, BufReader},
    mem,
    path::{Path, PathBuf},
    process::{self, Stdio},
};

use rocie_client::{
    apis::{api_set_no_auth_user_api::provision, configuration::Configuration},
    models::{ProvisionInfo, UserStub},
};

use crate::{
    _testenv::{Paths, log::request},
    testenv::TestEnv,
};

macro_rules! function_name {
    () => {{
        fn f() {}
        fn type_name_of<T>(_: T) -> &'static str {
            std::any::type_name::<T>()
        }
        let name = type_name_of(f);
        name.strip_suffix("::{{closure}}::f").unwrap()
    }};
}
pub(crate) use function_name;

fn target_dir() -> PathBuf {
    // Tests exe is in target/debug/deps, the *rocie-server* exe is in target/debug
    env::current_exe()
        .expect("./target/debug/deps/rocie-server-*")
        .parent()
        .expect("./target/debug/deps")
        .parent()
        .expect("./target/debug")
        .parent()
        .expect("./target")
        .to_path_buf()
}

fn test_dir(name: &'static str) -> PathBuf {
    target_dir().join("tests").join(name)
}

fn prepare_files_and_dirs(test_dir: &Path) -> io::Result<Paths> {
    fs::create_dir_all(test_dir)?;

    let db_path = test_dir.join("database.sqlite");

    {
        // Remove all files, so that the test run stays pure
        for entry in fs::read_dir(test_dir).unwrap() {
            let entry = entry.unwrap();
            let entry_ft = entry.file_type().unwrap();

            if entry_ft.is_dir() {
                fs::remove_dir_all(entry.path())?;
            } else if entry_ft.is_file() {
                fs::remove_file(entry.path())?;
            } else {
                panic!("Unknown file: {} ({entry_ft:#?})", entry.path().display());
            }
        }
    }

    Ok(Paths {
        db: db_path,
        test_dir: test_dir.to_owned(),
    })
}

fn find_server_exe() -> PathBuf {
    let target = target_dir();

    let prefixed_target = target.join(env!("TARGET"));

    let target = if prefixed_target.join("debug").exists() {
        prefixed_target.join("debug")
    } else if prefixed_target.join("release").exists() {
        prefixed_target.join("release")
    } else if target.join("debug").exists() {
        target.join("debug")
    } else if target.join("release").exists() {
        target.join("release")
    } else {
        panic!("Failed to find directory for rocie-server binary.");
    };

    let exe_name = if cfg!(windows) {
        "rocie-server.exe"
    } else {
        "rocie-server"
    };

    let final_path = target.join(exe_name);
    println!(
        "TESTENV: Assuming `rocie-server` binary is at: `{}`",
        final_path.display()
    );

    final_path
}

fn rocie_base_path(port: &str) -> String {
    format!("http://127.0.0.1:{port}")
}

fn rocie_server_args(paths: &Paths) -> [&OsStr; 4] {
    [
        OsStr::new("serve"),
        OsStr::new("--db-path"),
        paths.db.as_os_str(),
        OsStr::new("--print-port"),
    ]
}

impl TestEnv {
    pub(crate) async fn new(name: &'static str) -> TestEnv {
        let env = Self::new_no_login(name);

        request!(
            env,
            provision(ProvisionInfo {
                user: UserStub {
                    description: Some("Test user, used during test runs".to_string()),
                    name: "rocie".to_string(),
                    password: "server".to_string()
                },
                // Don't use any default units.
                // Otherwise we would need to update the tests every time we add new ones.
                use_defaults: false,
            })
        );

        env
    }

    pub(crate) fn new_no_login(name: &'static str) -> TestEnv {
        let test_dir = test_dir(name);

        let paths = prepare_files_and_dirs(&test_dir)
            .inspect_err(|err| panic!("Error during test dir preparation: {err}"))
            .unwrap();

        let (server_process, port) = {
            let server_exe = find_server_exe();
            let mut cmd = process::Command::new(&server_exe);

            cmd.current_dir(&paths.test_dir);

            cmd.stdout(Stdio::piped());
            cmd.stderr(Stdio::piped());

            cmd.args(rocie_server_args(&paths));

            let mut child = cmd.spawn().expect("server spawn");

            let port: u16 = {
                let mut stdout = BufReader::new(child.stdout.as_mut().expect("Was captured"));

                let mut port = String::new();
                assert_ne!(
                    stdout.read_line(&mut port).expect("Works"),
                    0,
                    "We should have been able to read the one line, the server printed"
                );

                port.trim_end()
                    .parse()
                    .expect("The server should reply with a u16 port number")
            };

            (child, port)
        };

        let config = {
            let mut inner = Configuration::new();
            inner.base_path = rocie_base_path(port.to_string().as_str());
            inner.user_agent = Some(String::from("Rocie test driver"));
            inner
        };

        let me = TestEnv {
            name,
            test_dir,
            paths,
            server_process: Some(server_process),
            config,
            port: port.to_string(),
        };

        me.log(format!("Starting test `{name}` on port `{port}`"));

        me
    }
}

impl Drop for TestEnv {
    fn drop(&mut self) {
        /// Format an error message for when the server did not exit successfully.
        fn format_exit(args: &[&OsStr], output: &process::Output) -> String {
            let mut base = String::new();

            {
                let args = args
                    .iter()
                    .map(|s| s.to_str().unwrap())
                    .collect::<Vec<_>>()
                    .join(" ");

                if output.status.success() {
                    writeln!(base, "`rocie-server {args}` did exit successfully.")
                        .expect("In-memory");
                } else {
                    writeln!(base, "`rocie-server {args}` did not exit successfully.")
                        .expect("In-memory");
                }
            }

            let stdout = String::from_utf8_lossy(&output.stdout);
            let stderr = String::from_utf8_lossy(&output.stderr);

            if !stdout.is_empty() {
                writeln!(base, "Stdout:\n---\n{stdout}\n---").expect("In-memory");
            }
            if !stderr.is_empty() {
                writeln!(base, "Stderr:\n---\n{stderr}\n---").expect("In-memory");
            }

            base
        }

        {
            // Stop the server process via SIGTERM.
            let mut kill = process::Command::new("kill")
                .args([
                    "-s",
                    "TERM",
                    &self.server_process.as_ref().unwrap().id().to_string(),
                ])
                .spawn()
                .unwrap();

            eprintln!("Killing the server process");

            kill.wait().unwrap();
        }

        let output = mem::take(&mut self.server_process)
            .expect("Is some at this point")
            .wait_with_output()
            .expect("server exit output");

        eprintln!(
            "{}",
            format_exit(rocie_server_args(&self.paths).as_slice(), &output)
        );
    }
}