use crate::actions::transmission::{TransmissionAction, TransmissionConfig};
use crate::db::Database;
use crate::magnet::{extract_magnet_links, Magnet};
use chrono::{DateTime, Utc};
use clap::Parser;
use clap_verbosity_flag::{InfoLevel, Verbosity};
use color_eyre::eyre::{eyre, Result, WrapErr};
use directories::ProjectDirs;
use figment::providers::Env;
use figment::{
    providers::{Format, Toml},
    Figment,
};
use figment_file_provider_adapter::FileAdapter;
use log::{debug, info, warn};
use multimap::MultiMap;
use reddit_client::RedditClient;
use regex::Regex;
use serde::{Deserialize, Serialize};
use std::collections::{HashMap, HashSet};
use std::fs::create_dir_all;
use std::path::{Path, PathBuf};

mod actions;
mod db;
mod magnet;
mod models;
mod reddit_client;
mod schema;

#[derive(Debug, Serialize, Deserialize)]
struct SourceConfig {
    username: String,
    title_filter: Option<String>,
}

#[derive(Debug, Serialize, Deserialize)]
struct Config {
    #[serde(default)]
    transmission: Option<TransmissionConfig>,

    #[serde(default)]
    sources: HashMap<String, SourceConfig>,
}

#[derive(Debug)]
struct PostInfo {
    title: String,
    submitter: String,
    magnet_links: Vec<Magnet>,
    subreddit: String,
    timestamp: DateTime<Utc>,
}

#[derive(Parser, Debug)]
#[command(author, version, about = "Display recent posts from a Reddit user")]
struct Args {
    /// Path to the configuration file
    #[arg(short, long)]
    config: Option<String>,

    /// Path to the database file
    #[arg(short, long)]
    db: Option<String>,

    #[command(flatten)]
    verbose: Verbosity<InfoLevel>,
}

/// Filters posts based on a title filter pattern
fn filter_posts(title: &str, title_filter: Option<Regex>) -> bool {
    match title_filter {
        Some(pattern) => pattern.is_match(title),
        None => true,
    }
}

/// Prints the posts with their magnet links
fn print_posts(posts: &[PostInfo], username: &str, title_filter: Option<Regex>) -> usize {
    println!("Magnet links from u/{}:", username);
    if let Some(pattern) = title_filter {
        println!("Filtering titles by pattern: {}", pattern);
    }
    println!("----------------------------");

    let mut post_count = 0;

    for post in posts {
        // Only display posts with magnet links
        if !post.magnet_links.is_empty() {
            post_count += 1;

            println!(
                "{}. [r/{}] {} (Posted: {})",
                post_count,
                post.subreddit,
                post.title,
                post.timestamp.format("%Y-%m-%d %H:%M:%S")
            );

            for (i, link) in post.magnet_links.iter().enumerate() {
                println!("   Link {}: {}", i + 1, link);
            }
            println!();
        }
    }

    if post_count == 0 {
        println!("No posts with magnet links found.");
    }

    post_count
}

#[tokio::main]
async fn main() -> Result<()> {
    color_eyre::install()?;

    let args = Args::parse();

    pretty_env_logger::formatted_timed_builder()
        .filter_level(args.verbose.log_level_filter())
        .init();

    // Initialize database
    let db_path = match args.db {
        Some(path) => PathBuf::from(path),
        None => ProjectDirs::from("fr", "enoent", "reddit-magnet")
            .map(|p| p.data_dir().join("reddit-magnet.db"))
            .ok_or_else(|| eyre!("Could not determine data directory"))?,
    };

    // Create parent directory if it doesn't exist
    if let Some(parent) = db_path.parent() {
        create_dir_all(parent)
            .wrap_err_with(|| format!("Failed to create directory: {:?}", parent))?;
    }

    let mut db = Database::new(&db_path)
        .wrap_err_with(|| format!("Failed to initialize database at {:?}", db_path))?;

    let mut conf_extractor = Figment::new();
    let config_file_path: Option<PathBuf> = match args.config {
        Some(path) => Some(Path::new(&path).to_path_buf()),
        None => ProjectDirs::from("fr", "enoent", "reddit-magnet")
            .map(|p| p.config_dir().join("config.toml")),
    };
    match config_file_path {
        Some(path) => {
            if path.exists() {
                debug!("Reading configuration from {:?}", path);
                conf_extractor = conf_extractor.merge(FileAdapter::wrap(Toml::file_exact(path)));
            } else {
                debug!("Configuration file doesn't exist at {:?}", path);
            }
        }
        None => {
            debug!("No configuration file specified, using default configuration");
        }
    }

    let conf: Config = conf_extractor
        .merge(FileAdapter::wrap(Env::prefixed("REDDIT_MAGNET_")))
        .extract()
        .wrap_err_with(|| "Invalid configuration or insufficient command line arguments")?;

    if conf.sources.is_empty() {
        return Err(eyre!("No sources found in configuration. Please add at least one source to your configuration file.").into());
    }

    let mut unique_usernames = HashSet::new();
    for (_, source_config) in &conf.sources {
        unique_usernames.insert(source_config.username.clone());
    }

    let reddit_client = RedditClient::new();
    let mut user_posts = MultiMap::new();
    for username in unique_usernames {
        let submissions = reddit_client.fetch_user_submissions(&username).await?;
        user_posts.insert_many(username, submissions);
    }

    // Process sources and store magnet links
    for (source_name, source_config) in conf.sources {
        println!("\nProcessing source [{}]", source_name);

        let username = source_config.username.clone();
        let title_filter = match source_config.title_filter {
            Some(filter) => Some(
                Regex::new(filter.as_str())
                    .context(format!("Invalid regex pattern: {}", filter))?,
            ),
            None => None,
        };

        if let Some(submissions) = user_posts.get_vec(&username) {
            let mut filtered_posts = Vec::new();

            for post in submissions
                .iter()
                .filter(|s| filter_posts(&*s.title, title_filter.clone()))
            {
                let title = &post.title;
                let body = &post.body;
                let subreddit = &post.subreddit;

                let magnet_links = extract_magnet_links(body);
                if !magnet_links.is_empty() {
                    let post_info = PostInfo {
                        title: title.to_string(),
                        submitter: username.clone(),
                        subreddit: subreddit.to_string(),
                        magnet_links,
                        timestamp: post.created,
                    };

                    // Store the post info in the database
                    if let Err(e) = db.store_magnets(&post_info) {
                        warn!("Failed to store post info in database: {}", e);
                    }

                    filtered_posts.push(post_info);
                }
            }

            print_posts(&filtered_posts, &username, title_filter);
        }
    }

    // Process magnet links with Transmission if enabled
    if let Some(transmission_config) = conf.transmission {
        if transmission_config.enable {
            info!("Processing magnet links with Transmission");
            match TransmissionAction::new(&transmission_config, db).await {
                Ok(mut transmission_action) => {
                    match transmission_action.process_unprocessed_magnets().await {
                        Ok(count) => {
                            info!(
                                "Successfully processed {} magnet links with Transmission",
                                count
                            );
                        }
                        Err(e) => {
                            warn!("Failed to process magnet links with Transmission: {}", e);
                        }
                    }
                }
                Err(e) => {
                    warn!("Failed to initialize Transmission action: {}", e);
                }
            }
        } else {
            debug!("Transmission action is disabled");
        }
    } else {
        debug!("No Transmission configuration found");
    }

    Ok(())
}