use codespan_reporting::files::SimpleFiles;
use codespan_reporting::term;
use codespan_reporting::term::termcolor::{ColorChoice, StandardStream};
use deimos::ast::build::build_ast;
use deimos::name_analysis::analyze_names;
use deimos::name_analysis::symbol_table::SymbolTable;
use deimos::parser::{DeimosParser, Rule};
use deimos::std_core::add_std_core_symbols;
use pest::Parser;
use std::path::PathBuf;

pub fn name_analysis(paths: &Vec<PathBuf>) -> Result<(), Box<dyn std::error::Error>> {
    let mut compilation_units = vec![];
    let mut files: SimpleFiles<String, String> = SimpleFiles::new();

    for path in paths {
        let src = std::fs::read_to_string(path).unwrap();
        let parse_result = DeimosParser::parse(Rule::CompilationUnit, &src);
        let file_id = files.add(path.display().to_string(), src.clone()); // I don't love this clone

        match parse_result {
            Ok(mut pairs) => {
                let compilation_unit = build_ast(file_id, &mut pairs);
                compilation_units.push(compilation_unit);
                Ok::<(), Box<dyn std::error::Error>>(())
            }
            Err(e) => Err(e.into()),
        }?;
    }

    let mut symbol_table = SymbolTable::new();
    add_std_core_symbols(&mut symbol_table).expect("Failed to add std::core symbols.");

    let diagnostics = analyze_names(&compilation_units, &files, &mut symbol_table);
    if diagnostics.is_empty() {
        println!("Name analysis complete.");
        println!("{}", symbol_table);
    } else {
        let writer = StandardStream::stderr(ColorChoice::Always);
        let config = term::Config::default();
        for diagnostic in diagnostics {
            term::emit(&mut writer.lock(), &config, &files, &diagnostic)?;
        }
    }

    Ok(())
}