use crate::app::tab::Tab;
use crate::app::TextEditor;
use std::fs;
use std::path::PathBuf;

pub(crate) fn new_file(app: &mut TextEditor) {
    app.add_new_tab();
}

fn is_text_file(path: &PathBuf) -> bool {
    if let Some(extension) = path.extension().and_then(|s| s.to_str()) {
        matches!(
            extension.to_lowercase().as_str(),
            "txt"
                | "md"
                | "markdown"
                | "rs"
                | "py"
                | "js"
                | "ts"
                | "tsx"
                | "jsx"
                | "c"
                | "cpp"
                | "cc"
                | "cxx"
                | "h"
                | "hpp"
                | "java"
                | "go"
                | "php"
                | "rb"
                | "cs"
                | "swift"
                | "kt"
                | "scala"
                | "sh"
                | "bash"
                | "zsh"
                | "fish"
                | "html"
                | "htm"
                | "xml"
                | "css"
                | "scss"
                | "sass"
                | "json"
                | "yaml"
                | "yml"
                | "toml"
                | "sql"
                | "lua"
                | "vim"
                | "dockerfile"
                | "makefile"
                | "gitignore"
                | "conf"
                | "cfg"
                | "ini"
                | "log"
                | "csv"
                | "tsv"
        )
    } else {
        // Files without extensions might be text files, but let's be conservative
        // and only include them if they're small and readable
        if let Ok(metadata) = fs::metadata(path) {
            metadata.len() < 1024 * 1024 // Only consider files smaller than 1MB
        } else {
            false
        }
    }
}

pub(crate) fn open_files_from_directory(
    app: &mut TextEditor,
    dir_path: PathBuf,
) -> Result<usize, String> {
    if !dir_path.is_dir() {
        return Err(format!("{} is not a directory", dir_path.display()));
    }

    let entries = fs::read_dir(&dir_path)
        .map_err(|e| format!("Failed to read directory {}: {}", dir_path.display(), e))?;

    let mut opened_count = 0;
    let mut text_files: Vec<PathBuf> = Vec::new();

    // Collect all text files in the directory
    for entry in entries {
        let entry = entry.map_err(|e| format!("Failed to read directory entry: {}", e))?;
        let path = entry.path();

        if path.is_file() && is_text_file(&path) {
            text_files.push(path);
        }
    }

    // Sort files by name for consistent ordering
    text_files.sort();

    // Open each text file
    for file_path in text_files {
        match open_file_from_path(app, file_path.clone()) {
            Ok(()) => opened_count += 1,
            Err(e) => eprintln!("Warning: {}", e),
        }
    }

    if opened_count == 0 {
        Err(format!(
            "No text files found in directory {}",
            dir_path.display()
        ))
    } else {
        Ok(opened_count)
    }
}

pub(crate) fn open_file(app: &mut TextEditor) {
    if let Some(path) = rfd::FileDialog::new()
        .add_filter("Text files", &["*"])
        .pick_file()
    {
        match fs::read_to_string(&path) {
            Ok(content) => {
                let should_replace_current_tab = if let Some(active_tab) = app.get_active_tab() {
                    active_tab.file_path.is_none()
                        && active_tab.content.is_empty()
                        && !active_tab.is_modified
                } else {
                    false
                };

                if should_replace_current_tab {
                    if let Some(active_tab) = app.get_active_tab_mut() {
                        let title = path
                            .file_name()
                            .and_then(|n| n.to_str())
                            .unwrap_or("Untitled");
                        active_tab.content = content;
                        active_tab.file_path = Some(path.to_path_buf());
                        active_tab.title = title.to_string();
                        active_tab.mark_as_saved();
                    }
                    app.text_needs_processing = true;
                } else {
                    let new_tab = Tab::new_with_file(content, path);
                    app.tabs.push(new_tab);
                    app.active_tab_index = app.tabs.len() - 1;
                    app.text_needs_processing = true;
                }
                if app.show_find && !app.find_query.is_empty() {
                    app.update_find_matches();
                }

                if let Err(e) = app.save_state_cache() {
                    eprintln!("Failed to save state cache: {e}");
                }
            }
            Err(err) => {
                eprintln!("Failed to open file: {err}");
            }
        }
    }
}

pub(crate) fn open_file_from_path(app: &mut TextEditor, path: PathBuf) -> Result<(), String> {
    match fs::read_to_string(&path) {
        Ok(content) => {
            let should_replace_current_tab = if let Some(active_tab) = app.get_active_tab() {
                active_tab.file_path.is_none()
                    && active_tab.content.is_empty()
                    && !active_tab.is_modified
            } else {
                false
            };

            if should_replace_current_tab {
                if let Some(active_tab) = app.get_active_tab_mut() {
                    let title = path
                        .file_name()
                        .and_then(|n| n.to_str())
                        .unwrap_or("Untitled");
                    active_tab.content = content;
                    active_tab.file_path = Some(path.to_path_buf());
                    active_tab.title = title.to_string();
                    active_tab.mark_as_saved();
                }
                app.text_needs_processing = true;
            } else {
                let new_tab = Tab::new_with_file(content, path);
                app.tabs.push(new_tab);
                app.active_tab_index = app.tabs.len() - 1;
                app.text_needs_processing = true;
            }

            if app.show_find && !app.find_query.is_empty() {
                app.update_find_matches();
            }

            if let Err(e) = app.save_state_cache() {
                eprintln!("Failed to save state cache: {e}");
            }

            Ok(())
        }
        Err(err) => Err(format!("Failed to open file {}: {}", path.display(), err)),
    }
}

pub(crate) fn save_file(app: &mut TextEditor) {
    if let Some(active_tab) = app.get_active_tab() {
        if let Some(path) = &active_tab.file_path {
            save_to_path(app, path.to_path_buf());
        } else {
            save_as_file(app);
        }
    }
}

pub(crate) fn save_as_file(app: &mut TextEditor) {
    if let Some(path) = rfd::FileDialog::new()
        .add_filter("Text files", &["*"])
        .save_file()
    {
        save_to_path(app, path);
    }
}

pub(crate) fn save_to_path(app: &mut TextEditor, path: PathBuf) {
    if let Some(active_tab) = app.get_active_tab_mut() {
        match fs::write(&path, &active_tab.content) {
            Ok(()) => {
                let title = path
                    .file_name()
                    .and_then(|n| n.to_str())
                    .unwrap_or("Untitled");
                active_tab.file_path = Some(path.to_path_buf());
                active_tab.title = title.to_string();
                active_tab.mark_as_saved();

                if let Err(e) = app.save_state_cache() {
                    eprintln!("Failed to save state cache: {e}");
                }
            }
            Err(err) => {
                eprintln!("Failed to save file: {err}");
            }
        }
    }
}