use crate::building::linker::{LinkError, Linker};
use crate::building::output::{compile_project, CompileError};
use crate::building::plan::{BuildPlan, BuildTarget};
use crate::common::files::FileManager;
use crate::deps::resolver::ResolvedGraph;
use prometeu_core::virtual_machine::ProgramImage;
use std::collections::HashMap;

#[derive(Debug)]
pub enum BuildError {
    Compile(CompileError),
    Link(LinkError),
}

#[derive(Debug, Clone)]
pub struct BuildResult {
    pub image: ProgramImage,
    pub file_manager: FileManager,
    pub symbols: Vec<crate::common::symbols::ProjectSymbols>,
}

impl std::fmt::Display for BuildError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            BuildError::Compile(e) => write!(f, "Compile error: {}", e),
            BuildError::Link(e) => write!(f, "Link error: {}", e),
        }
    }
}

impl std::error::Error for BuildError {}

impl From<CompileError> for BuildError {
    fn from(e: CompileError) -> Self {
        BuildError::Compile(e)
    }
}

impl From<LinkError> for BuildError {
    fn from(e: LinkError) -> Self {
        BuildError::Link(e)
    }
}

pub fn build_from_graph(graph: &ResolvedGraph, target: BuildTarget) -> Result<BuildResult, BuildError> {
    let plan = BuildPlan::from_graph(graph, target);
    let mut compiled_modules = HashMap::new();
    let mut modules_in_order = Vec::new();
    let mut file_manager = FileManager::new();

    for step in &plan.steps {
        let compiled = compile_project(step.clone(), &compiled_modules, &mut file_manager)?;
        compiled_modules.insert(step.project_id.clone(), compiled.clone());
        modules_in_order.push(compiled);
    }

    let program_image = Linker::link(modules_in_order.clone(), plan.steps.clone())?;

    let mut all_project_symbols = Vec::new();
    for (i, module) in modules_in_order.into_iter().enumerate() {
        all_project_symbols.push(crate::common::symbols::ProjectSymbols {
            project: module.project_id.name.clone(),
            project_dir: plan.steps[i].project_dir.to_string_lossy().to_string(),
            symbols: module.symbols,
        });
    }

    Ok(BuildResult {
        image: program_image,
        file_manager,
        symbols: all_project_symbols,
    })
}