use crate::cli;
use crate::manifest;
use std::path::Path;
use thiserror::Error as TeError;

// region: Error Handling

/// Error occurs in this module.
#[derive(Debug, TeError)]
pub enum Error {
    /// Error when parsing Manifest TOML file.
    #[error("{0}")]
    ParseManifest(#[from] manifest::ParseManifestError),
    /// Error when parsing Manifest into Schema.
    #[error("{0}")]
    ParseSchema(#[from] manifest::ParseSchemaError),
    /// Error when parsing Schema into Program.
    #[error("{0}")]
    ParseProgram(#[from] wfassoc::highlevel::ParseProgramError),
    /// Error when operating Program.
    #[error("{0}")]
    Program(#[from] wfassoc::highlevel::ProgramError),
}

/// Result type used in this module.
type Result<T> = std::result::Result<T, Error>;

// endregion

// region: Utilities Functions

fn stringified_exts_to_indices(program: &wfassoc::Program, exts: Vec<String>) -> Result<Vec<usize>> {
    todo!()
}

// endregion

// region: Respective Runners

fn run_register(mut program: wfassoc::Program, scope: wfassoc::Scope) -> Result<()> {
    Ok(program.register(scope)?)
}

fn run_unregister(mut program: wfassoc::Program, scope: wfassoc::Scope) -> Result<()> {
    Ok(program.unregister(scope)?)
}

fn run_status(program: wfassoc::Program, view: wfassoc::View) -> Result<()> {
    if program.is_registered(view)? {
        println!("Application is installed.");
    } else {
        println!("Application is not installed.");
    }
    
    Ok(())
}

fn run_ext_link(program: wfassoc::Program, scope: wfassoc::Scope, exts: Vec<String>) -> Result<()> {
    let exts = stringified_exts_to_indices(&program, exts)?;
    todo!()
}

fn run_ext_unlink(
    program: wfassoc::Program,
    scope: wfassoc::Scope,
    exts: Vec<String>,
) -> Result<()> {
    let exts = stringified_exts_to_indices(&program, exts)?;
    todo!()
}

fn run_ext_list(
    program: wfassoc::Program,
    view: wfassoc::View,
    style: cli::ExtListStyle,
) -> Result<()> {
    todo!()
}

// endregion

pub fn run(c: cli::Cli) -> Result<()> {
    // Read manifest file first
    let mf = manifest::Manifest::from_file(Path::new(&c.manifest_file))?;
    println!("{:?}", mf);
    // Parse it into schema
    let schema = mf.into_schema()?;
    // Parse it into program
    let program = schema.into_program()?;

    match c.command {
        cli::CliCommands::Register { target } => run_register(program, target.into()),
        cli::CliCommands::Unregister { target } => run_unregister(program, target.into()),
        cli::CliCommands::Status { target } => run_status(program, target.into()),
        cli::CliCommands::Ext { command } => match command {
            cli::CliExtCommands::Link { target, exts } => {
                run_ext_link(program, target.into(), exts)
            }
            cli::CliExtCommands::Unlink { target, exts } => {
                run_ext_unlink(program, target.into(), exts)
            }
            cli::CliExtCommands::List { target, style } => {
                run_ext_list(program, target.into(), style)
            }
        },
    }
}