use serde::{Deserialize, Serialize};
use std::process::Command;

use arboard::Clipboard;

#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
#[serde(rename_all = "camelCase")]
pub struct FocusTarget {
    pub platform: Platform,
    pub display_server: DisplayServer,
    pub window_title: Option<String>,
    pub process_name: Option<String>,
}

#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
#[serde(rename_all = "camelCase")]
pub enum Platform {
    Windows,
    Linux,
    Unknown,
}

#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
#[serde(rename_all = "camelCase")]
pub enum DisplayServer {
    Windows,
    X11,
    Wayland,
    Unknown,
}

#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
#[serde(rename_all = "camelCase")]
pub enum InsertCapability {
    Full,
    Partial,
    Unsupported,
}

#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
#[serde(rename_all = "camelCase")]
pub enum InsertMethod {
    ClipboardPaste,
    KeyTyping,
    ManualCopy,
}

#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
#[serde(rename_all = "camelCase")]
pub struct InsertRequest {
    pub text: String,
    pub target: Option<FocusTarget>,
    pub method: InsertMethod,
}

#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
#[serde(rename_all = "camelCase")]
pub struct InsertResult {
    pub capability: InsertCapability,
    pub method_used: InsertMethod,
    pub message: String,
}

pub trait TextInjector {
    fn can_insert(&self, target: Option<&FocusTarget>) -> InsertCapability;
    fn insert_text(&self, request: InsertRequest) -> InsertResult;
}

#[derive(Debug, Default, Clone)]
pub struct FallbackInjector;

impl TextInjector for FallbackInjector {
    fn can_insert(&self, target: Option<&FocusTarget>) -> InsertCapability {
        let display_server = target
            .map(|target| target.display_server.clone())
            .unwrap_or_else(current_display_server);

        match display_server {
            DisplayServer::Windows | DisplayServer::X11 => InsertCapability::Full,
            DisplayServer::Wayland => InsertCapability::Partial,
            DisplayServer::Unknown => InsertCapability::Unsupported,
        }
    }

    fn insert_text(&self, request: InsertRequest) -> InsertResult {
        let capability = self.can_insert(request.target.as_ref());
        let clipboard_message = copy_to_clipboard(&request.text);

        let message = match (&request.method, &capability) {
            (InsertMethod::ManualCopy, _) => clipboard_message.unwrap_or_else(|error| error),
            (_, InsertCapability::Full) => match clipboard_message {
                Ok(_) => match trigger_paste() {
                    Ok(_) => "Texto copiado e Ctrl+V acionado no app em foco.".to_string(),
                    Err(error) => format!(
                        "Texto copiado. Não consegui acionar Ctrl+V automaticamente: {error}"
                    ),
                },
                Err(error) => error,
            },
            (_, InsertCapability::Partial) => match clipboard_message {
                Ok(_) => "Texto copiado. No Wayland, cole manualmente com Ctrl+V.".to_string(),
                Err(error) => error,
            },
            (_, InsertCapability::Unsupported) => match clipboard_message {
                Ok(_) => "Texto copiado. Cole manualmente no aplicativo desejado.".to_string(),
                Err(error) => error,
            },
        };

        InsertResult {
            capability,
            method_used: request.method,
            message,
        }
    }
}

fn current_display_server() -> DisplayServer {
    #[cfg(target_os = "windows")]
    {
        DisplayServer::Windows
    }

    #[cfg(target_os = "linux")]
    {
        let session_type = std::env::var("XDG_SESSION_TYPE")
            .unwrap_or_default()
            .to_lowercase();
        if session_type == "wayland" || std::env::var_os("WAYLAND_DISPLAY").is_some() {
            DisplayServer::Wayland
        } else if session_type == "x11" || std::env::var_os("DISPLAY").is_some() {
            DisplayServer::X11
        } else {
            DisplayServer::Unknown
        }
    }

    #[cfg(not(any(target_os = "windows", target_os = "linux")))]
    {
        DisplayServer::Unknown
    }
}

fn copy_to_clipboard(text: &str) -> Result<String, String> {
    let mut clipboard = Clipboard::new().map_err(|error| format!("Falha ao acessar clipboard: {error}"))?;
    clipboard
        .set_text(text.to_string())
        .map_err(|error| format!("Falha ao copiar texto: {error}"))?;
    Ok("Texto copiado para o clipboard.".to_string())
}

fn trigger_paste() -> Result<(), String> {
    #[cfg(target_os = "windows")]
    {
        let status = Command::new("powershell")
            .args([
                "-NoProfile",
                "-Command",
                "Add-Type -AssemblyName System.Windows.Forms; [System.Windows.Forms.SendKeys]::SendWait('^v')",
            ])
            .status()
            .map_err(|error| error.to_string())?;
        return status
            .success()
            .then_some(())
            .ok_or_else(|| format!("powershell retornou {status}"));
    }

    #[cfg(target_os = "linux")]
    {
        let status = Command::new("xdotool")
            .args(["key", "--clearmodifiers", "ctrl+v"])
            .status()
            .map_err(|error| error.to_string())?;
        return status
            .success()
            .then_some(())
            .ok_or_else(|| format!("xdotool retornou {status}"));
    }

    #[allow(unreachable_code)]
    Err("paste automático não suportado neste sistema".to_string())
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn wayland_reports_partial_insert_capability() {
        let injector = FallbackInjector;
        let target = FocusTarget {
            platform: Platform::Linux,
            display_server: DisplayServer::Wayland,
            window_title: Some("Editor".to_string()),
            process_name: Some("app".to_string()),
        };

        assert_eq!(
            injector.can_insert(Some(&target)),
            InsertCapability::Partial
        );
    }
}