use std::{collections::HashSet, io::Write, path::Path};

use crate::{
    logger::Logger,
    normalizer::{NormalizeError, NormalizedPath, Normalizer},
    renderer::Renderer,
    util::path_display::display_path,
};

use super::MarkdownGenerator;

pub(super) struct MarkdownGeneration<'a, W: Write> {
    logger: Logger,
    normalizer: Normalizer,
    paths: &'a [&'a Path],
    project_title: String,
    renderer: Renderer<W>,
    seen_paths: HashSet<NormalizedPath>,
}

impl<'a, W: Write> MarkdownGeneration<'a, W> {
    pub fn new(generator: MarkdownGenerator<'a>, output: W) -> Result<Self, NormalizeError> {
        let renderer =
            Renderer::new(output, generator.render_options).with_logger(generator.logger);
        Ok(Self {
            logger: generator.logger,
            normalizer: Normalizer::new(generator.root, generator.origin_base)?,
            paths: generator.paths,
            project_title: generator.get_or_derive_project_title().to_string(),
            renderer,
            seen_paths: HashSet::new(),
        })
    }

    pub fn run(mut self) -> Result<(), Box<dyn std::error::Error>> {
        self.renderer.render_header(&self.project_title)?;
        for path in self.paths {
            self.render_path(path)?;
        }
        Ok(())
    }

    fn render_path(&mut self, path: &Path) -> Result<(), Box<dyn std::error::Error>> {
        let normalized_path = self.normalizer.normalize(path)?;
        if self.seen_paths.insert(normalized_path.clone()) {
            self.renderer.render_path(&normalized_path)?;
        } else {
            self.logger.warn(format!(
                "skipping duplicate file: {}",
                display_path(&normalized_path.root_relative)
            ));
        }
        Ok(())
    }
}