use std::path::PathBuf;
use anyhow::{Result, anyhow};
use chrono::NaiveDate;
use regex::Regex;
use video_processing::{
    VideoProcessingConfig, VideoConverter as SharedVideoConverter, NfoGenerator, FileProcessor
};

pub struct VideoConverter {
    output_path: PathBuf,
    config: VideoProcessingConfig,
    video_converter: SharedVideoConverter,
    nfo_generator: NfoGenerator,
}

impl VideoConverter {
    pub fn new(output_path: PathBuf) -> Self {
        let config = VideoProcessingConfig::from_env();
        let video_converter = SharedVideoConverter::new(config.clone());
        let nfo_generator = NfoGenerator::new(config.clone());
        
        VideoConverter {
            output_path,
            config,
            video_converter,
            nfo_generator,
        }
    }

    // Note: File stability checking is now handled by the caller using the shared crate

    pub async fn extract_date_from_filename(&self, filename: &str) -> Result<NaiveDate> {
        // Example filename: "Sermon Title - Speaker (December 4th 2024).mp4"
        if let Some(date_part) = filename.split('(').nth(1).and_then(|part| part.split(')').next()) {
            let re = Regex::new(r"(?i)(January|February|March|April|May|June|July|August|September|October|November|December)\s+(\d+)(?:st|nd|rd|th)?\s+(\d{4})")?;
            
            if let Some(caps) = re.captures(date_part) {
                let month = caps.get(1).unwrap().as_str();
                let day = caps.get(2).unwrap().as_str();
                let year = caps.get(3).unwrap().as_str();
                
                let date_str = format!("{} {} {}", day, month, year);
                let date = NaiveDate::parse_from_str(&date_str, "%d %B %Y")?;
                Ok(date)
            } else {
                Err(anyhow!("Could not extract date from filename part within parentheses"))
            }
        } else {
            Err(anyhow!("No date found in parentheses in filename"))
        }
    }

    pub async fn extract_title_and_speaker(&self, filename: &str) -> Result<(String, String)> {
        // Example: "God's People in the Time of the End - Pastor Joseph Piresson (December 28th 2024).mp4"
        if let Some(main_part) = filename.split('(').next() {
            if let Some((title, speaker)) = main_part.split_once('-') {
                return Ok((
                    title.trim().to_string(),
                    speaker.trim().to_string()
                ));
            }
        }
        Err(anyhow!("Could not extract title and speaker from filename"))
    }


    pub async fn process_file(&self, path: PathBuf) -> Result<()> {
        // Early checks
        if path.to_string_lossy().contains(".syncthing.") {
            return Err(anyhow!("Skipping Syncthing temporary file"));
        }

        if path.extension().and_then(|ext| ext.to_str()) != Some("mp4") {
            return Err(anyhow!("Ignoring non-MP4 file"));
        }

        if !path.exists() {
            return Err(anyhow!("File no longer exists: {}", path.display()));
        }

        // Note: File stability is now handled by the caller

        println!("Processing sermon: {}", path.display());
        
        // Get the filename
        let filename = path.file_name()
            .ok_or_else(|| anyhow!("Invalid filename"))?
            .to_str()
            .ok_or_else(|| anyhow!("Invalid UTF-8 in filename"))?;

        // Extract date, title, and speaker from filename
        let date = self.extract_date_from_filename(filename).await?;
        let (title, speaker) = self.extract_title_and_speaker(filename).await?;
        
        // Create date-based directory structure
        let year_dir = self.output_path.join(date.format("%Y").to_string());
        let month_dir = year_dir.join(format!("{}-{}", 
            date.format("%m"),    // numeric month (12)
            date.format("%B")     // full month name (December)
        ));
        
        // Create directories if they don't exist
        tokio::fs::create_dir_all(&month_dir).await?;

        // Keep original filename but ensure .mp4 extension
        let output_file = month_dir.join(filename);
        
        println!("Converting to AV1 and saving to: {}", output_file.display());

        // Convert video using shared crate
        self.video_converter.convert_video(&path, &output_file).await?;

        // Create NFO file using shared crate
        let full_title = format!("{} - {}", title, speaker);
        self.nfo_generator.create_nfo_file(&output_file, &full_title, &date, None).await?;

        println!("Successfully converted {} to AV1 and created NFO", path.display());

        // Handle original file based on configuration
        if !self.config.preserve_original_files {
            println!("Deleting original file: {}", path.display());
            tokio::fs::remove_file(path).await?;
        } else {
            println!("Preserving original file: {}", path.display());
        }

        Ok(())
    }
}

#[async_trait::async_trait]
impl FileProcessor for VideoConverter {
    async fn process_file(&self, path: PathBuf) -> Result<()> {
        self.process_file(path).await
    }

    async fn should_skip_existing_file(&self, _path: &PathBuf) -> bool {
        // For sermons, we don't have a simple duplicate check like livestreams
        // Let the process_file method handle duplicate detection
        false
    }
}