use codespan_reporting::diagnostic::Label;
use codespan_reporting::files::SimpleFiles;
use codespan_reporting::term;
use codespan_reporting::term::termcolor::{ColorChoice, StandardStream};
use dm_std_lib::add_all_std_core;
use dmc_lib::constants_table::ConstantsTable;
use dmc_lib::diagnostic::Diagnostic;
use dmc_lib::intrinsics::{insert_intrinsic_symbols, insert_intrinsic_types};
use dmc_lib::offset_counter::OffsetCounter;
use dmc_lib::parser::get_compilation_unit;
use dmc_lib::symbol_table::SymbolTable;
use dmc_lib::types_table::TypesTable;
use dvm_lib::vm::constant::{Constant, StringConstant};
use dvm_lib::vm::function::Function;
use dvm_lib::vm::{DvmContext, call};
use std::path::PathBuf;
use std::rc::Rc;

pub fn compile_and_run_script(
    script: &PathBuf,
    show_ir: bool,
    show_asm: bool,
    register_count: usize,
) {
    let input = std::fs::read_to_string(script).unwrap();

    let mut files: SimpleFiles<&str, &str> = SimpleFiles::new();
    let script_file_id = files.add(script.to_str().unwrap(), &input);

    match run(&input, show_ir, show_asm, register_count) {
        Ok(_) => {}
        Err(diagnostics) => {
            check_and_report_diagnostics(&files, script_file_id, &diagnostics);
        }
    }
}

fn run(
    input: &str,
    show_ir: bool,
    show_asm: bool,
    register_count: usize,
) -> Result<(), Vec<Diagnostic>> {
    let mut compilation_unit = get_compilation_unit(&input, None)?;

    let mut symbol_table = SymbolTable::new();
    symbol_table.push_module_scope("global scope");
    insert_intrinsic_symbols(&mut symbol_table);
    let mut types_table = TypesTable::new();
    insert_intrinsic_types(&symbol_table, &mut types_table);

    compilation_unit.init_scopes(&mut symbol_table);
    compilation_unit.gather_symbols_into(&mut symbol_table)?;
    compilation_unit.check_names(&mut symbol_table)?;
    compilation_unit.gather_types_into(&symbol_table, &mut types_table)?;
    compilation_unit.type_check(&symbol_table, &mut types_table)?;

    let (ir_classes, mut ir_functions) = compilation_unit.to_ir(&symbol_table, &types_table);

    if show_ir {
        for ir_function in &ir_functions {
            println!("{}", ir_function);
        }
    }

    let mut functions: Vec<Function> = vec![];
    let mut constants_table = ConstantsTable::new();

    for ir_function in &mut ir_functions {
        let mut offset_counter = OffsetCounter::new();
        ir_function.assign_registers(register_count, &mut offset_counter);
        let function = ir_function.assemble(offset_counter.get_count(), &mut constants_table);
        functions.push(function);
    }

    let classes = ir_classes
        .iter()
        .map(|ir_class| ir_class.to_vm_class())
        .collect::<Vec<_>>();

    if show_asm {
        for function in &functions {
            println!("{}", function);
        }
    }

    let mut dvm_context = DvmContext::new();

    // add std::core fns
    add_all_std_core(&mut dvm_context);

    for function in functions {
        dvm_context
            .functions_mut()
            .insert(function.name_owned(), function);
    }

    for class in classes {
        dvm_context
            .classes_mut()
            .insert(class.fqn().into(), Rc::new(class));
    }

    for (name, content) in &constants_table.string_constants() {
        dvm_context.constants_mut().insert(
            name.clone(),
            Constant::String(StringConstant::new(name.clone(), content.clone())),
        );
    }

    let result = call(&dvm_context, "main", &vec![], register_count);

    if let Some(value) = result {
        println!("{}", value);
    }

    Ok(())
}

fn check_and_report_diagnostics(
    files: &SimpleFiles<&str, &str>,
    script_file_id: usize,
    diagnostics: &[Diagnostic],
) {
    if !diagnostics.is_empty() {
        report_and_exit(diagnostics, script_file_id, files);
    }
}

fn report_and_exit(
    diagnostics: &[Diagnostic],
    script_file_id: usize,
    files: &SimpleFiles<&str, &str>,
) -> ! {
    let writer = StandardStream::stderr(ColorChoice::Always);
    let config = term::Config::default();
    for diagnostic in diagnostics {
        let mut primary_label =
            Label::primary(script_file_id, diagnostic.start()..diagnostic.end());
        if let Some(primary_label_message) = diagnostic.primary_label_message() {
            primary_label = primary_label.with_message(primary_label_message);
        }

        let secondary_labels: Vec<Label<usize>> = diagnostic
            .secondary_labels()
            .iter()
            .map(|secondary_label| {
                let mut label = Label::secondary(
                    script_file_id,
                    secondary_label.start()..secondary_label.end(),
                );
                if let Some(message) = secondary_label.message() {
                    label = label.with_message(message);
                }
                label
            })
            .collect();

        let mut csr_diagnostic = codespan_reporting::diagnostic::Diagnostic::error()
            .with_message(diagnostic.message())
            .with_label(primary_label)
            .with_labels(secondary_labels);

        if let Some(error_code) = diagnostic.error_code() {
            csr_diagnostic = csr_diagnostic.with_code(format!("E{:04}", error_code));
        }

        if let Some((reporter_file, reporter_line)) = diagnostic.reporter() {
            csr_diagnostic = csr_diagnostic.with_note(format!(
                "Reported by (Rust) source: {}, line {}",
                reporter_file, reporter_line
            ));
        }

        term::emit_to_write_style(&mut writer.lock(), &config, files, &csr_diagnostic).unwrap();
    }
    if diagnostics.len() == 1 {
        eprintln!("There was 1 diagnostic. See above for more information.");
    } else {
        eprintln!(
            "There were {} diagnostics. See above for more information.",
            diagnostics.len()
        );
    }
    std::process::exit(1);
}