use super::*;

use std::{collections::HashMap, env, ffi::OsStr, path::Path, process::Command};

use anyhow::{anyhow, bail, Context, Result};

lazy_static::lazy_static! {
    pub static ref SHELL: Shell = detect_shell();
}

pub struct Shell {
    pub name: String,
    pub cmd: String,
    pub arg: String,
}

impl Shell {
    pub fn new(name: &str, cmd: &str, arg: &str) -> Self {
        Self {
            name: name.to_string(),
            cmd: cmd.to_string(),
            arg: arg.to_string(),
        }
    }
}

pub fn detect_shell() -> Shell {
    let os = env::consts::OS;
    if os == "windows" {
        if let Some(ret) = env::var("PSModulePath").ok().and_then(|v| {
            let v = v.to_lowercase();
            if v.split(';').count() >= 3 {
                if v.contains("powershell\\7\\") {
                    Some(Shell::new("pwsh", "pwsh.exe", "-c"))
                } else {
                    Some(Shell::new("powershell", "powershell.exe", "-Command"))
                }
            } else {
                None
            }
        }) {
            ret
        } else {
            Shell::new("cmd", "cmd.exe", "/C")
        }
    } else {
        let shell = env::var("SHELL").unwrap_or_else(|_| "/bin/sh".to_string());
        let shell = match shell.rsplit_once('/') {
            Some((_, v)) => v,
            None => &shell,
        };
        match shell {
            "bash" | "zsh" | "fish" | "pwsh" => Shell::new(shell, shell, "-c"),
            _ => Shell::new("sh", "sh", "-c"),
        }
    }
}

pub fn run_command<T: AsRef<OsStr>>(
    cmd: &str,
    args: &[T],
    envs: Option<HashMap<String, String>>,
) -> Result<i32> {
    let status = Command::new(cmd)
        .args(args.iter())
        .envs(envs.unwrap_or_default())
        .status()?;
    Ok(status.code().unwrap_or_default())
}

pub fn run_command_with_output<T: AsRef<OsStr>>(
    cmd: &str,
    args: &[T],
    envs: Option<HashMap<String, String>>,
) -> Result<(bool, String, String)> {
    let output = Command::new(cmd)
        .args(args.iter())
        .envs(envs.unwrap_or_default())
        .output()?;
    let status = output.status;
    let stdout = std::str::from_utf8(&output.stdout).context("Invalid UTF-8 in stdout")?;
    let stderr = std::str::from_utf8(&output.stderr).context("Invalid UTF-8 in stderr")?;
    Ok((status.success(), stdout.to_string(), stderr.to_string()))
}

pub fn run_loader_command(path: &str, extension: &str, loader_command: &str) -> Result<String> {
    let cmd_args = shell_words::split(loader_command).with_context(|| {
        anyhow!("Invalid rag document loader '{extension}': `{loader_command}`")
    })?;
    let mut use_stdout = true;
    let outpath = temp_file("-output-", "").display().to_string();
    let cmd_args: Vec<_> = cmd_args
        .into_iter()
        .map(|mut v| {
            if v.contains("$1") {
                v = v.replace("$1", path);
            }
            if v.contains("$2") {
                use_stdout = false;
                v = v.replace("$2", &outpath);
            }
            v
        })
        .collect();
    let cmd_eval = shell_words::join(&cmd_args);
    debug!("run `{cmd_eval}`");
    let (cmd, args) = cmd_args.split_at(1);
    let cmd = &cmd[0];
    if use_stdout {
        let (success, stdout, stderr) =
            run_command_with_output(cmd, args, None).with_context(|| {
                format!("Unable to run `{cmd_eval}`, Perhaps '{cmd}' is not installed?")
            })?;
        if !success {
            let err = if !stderr.is_empty() {
                stderr
            } else {
                format!("The command `{cmd_eval}` exited with non-zero.")
            };
            bail!("{err}")
        }
        Ok(stdout)
    } else {
        let status = run_command(cmd, args, None).with_context(|| {
            format!("Unable to run `{cmd_eval}`, Perhaps '{cmd}' is not installed?")
        })?;
        if status != 0 {
            bail!("The command `{cmd_eval}` exited with non-zero.")
        }
        let contents = std::fs::read_to_string(&outpath)
            .context("Failed to read file generated by the loader")?;
        Ok(contents)
    }
}

pub fn edit_file(editor: &str, path: &Path) -> Result<()> {
    let mut child = Command::new(editor).arg(path).spawn()?;
    child.wait()?;
    Ok(())
}