use std::collections::HashMap;
use std::error::Error;
use std::str::FromStr;

use actix_web::{HttpRequest, HttpResponse, web};
use actix_web::http::{HeaderName, HeaderValue};
use bytes::Bytes;
use exif::In;
use image::{GenericImageView, ImageFormat};
use serde::Serialize;

use crate::api_data::http_error::HttpError;
use crate::controllers::routes::RequestResult;
use crate::data::api_client::APIClient;
use crate::data::config::conf;
use crate::data::error::{ExecError, ResultBoxError};
use crate::data::group::GroupAccessLevel;
use crate::data::group_id::GroupID;
use crate::data::user::UserID;
use crate::helpers::{account_helper, api_helper, conversations_helper, friends_helper, groups_helper, user_helper, virtual_directory_helper};
use crate::helpers::virtual_directory_helper::VirtualDirType;
use crate::utils::string_utils::{check_url, remove_html_nodes};
use crate::utils::user_data_utils::{generate_new_user_data_file_name, prepare_file_creation, user_data_path};
use crate::utils::virtual_directories_utils::check_virtual_directory;

/// Http request handler
///
/// @author Pierre Hubert

pub struct PostFile {
    pub name: String,
    pub buff: Bytes,
}

/// Single request body  value
pub enum RequestValue {
    String(String),
    File(PostFile),
}

#[derive(Serialize)]
struct SuccessMessage {
    success: String
}

pub struct HttpRequestHandler {
    request: web::HttpRequest,
    body: HashMap<String, RequestValue>,
    response: Option<web::HttpResponse>,
    headers: HashMap<String, String>,
    client: Option<APIClient>,
    curr_user_id: Option<UserID>,
}

impl HttpRequestHandler {
    /// Construct a new request handler
    pub fn new(req: HttpRequest, body: HashMap<String, RequestValue>) -> HttpRequestHandler {
        HttpRequestHandler {
            request: req,
            body,
            response: None,
            headers: HashMap::new(),
            client: None,
            curr_user_id: None,
        }
    }

    /// Check if a response has been set for this request
    pub fn has_response(&self) -> bool {
        self.response.is_some()
    }

    /// Get the response status code, eg. 200 or 404
    pub fn response_status_code(&self) -> u16 {
        self.response.as_ref().unwrap().status().as_u16()
    }

    /// Take the response from this struct
    pub fn response(self) -> ResultBoxError<HttpResponse> {
        let mut response = self.response.unwrap();

        // Put additional headers if required
        for (k, v) in &self.headers {
            response.headers_mut().insert(HeaderName::from_str(k)?,
                                          HeaderValue::from_str(v)?,
            );
        }

        Ok(response)
    }

    /// Set request response
    pub fn set_response<T: Serialize>(&mut self, data: T) -> RequestResult {
        self.response = Some(HttpResponse::Ok().json(data));
        Ok(())
    }

    /// Success message
    pub fn success(&mut self, message: &str) -> RequestResult {
        self.response = Some(HttpResponse::Ok().json(SuccessMessage {
            success: message.to_string()
        }));
        Ok(())
    }

    /// Internal error response (500)
    pub fn internal_error(&mut self, error: Box<dyn Error>) -> RequestResult {
        self.response = Some(HttpResponse::InternalServerError().json(
            HttpError::internal_error("Internal server error.")));
        Err(error)
    }

    /// Bad request (400)
    pub fn bad_request(&mut self, message: String) -> RequestResult {
        self.response = Some(HttpResponse::BadRequest().json(
            HttpError::bad_request(&message)));
        Err(Box::new(ExecError::new(&message)))
    }

    /// Forbidden (401)
    ///
    /// I did not the HTTP official specs when I made this choice of using Unauthorized instead
    /// of Forbidden. Today it would be really complicated to come back...
    pub fn forbidden(&mut self, message: String) -> RequestResult {
        self.response = Some(HttpResponse::Unauthorized().json(
            HttpError::forbidden(&message)));
        Err(Box::new(ExecError::new(&message)))
    }

    /// Not found (404)
    pub fn not_found(&mut self, message: String) -> RequestResult {
        self.response = Some(HttpResponse::NotFound().json(
            HttpError::not_found(&message)));
        Err(Box::new(ExecError::new(&message)))
    }

    /// If result is not OK, return a bad request
    pub fn ok_or_bad_request<E>(&mut self, res: ResultBoxError<E>, msg: &str) -> ResultBoxError<E> {
        match res {
            Ok(e) => Ok(e),
            Err(err) => {
                println!("Error leading to bad request: {}", err);
                self.bad_request(msg.to_string())?;
                unreachable!()
            }
        }
    }

    /// If result is not OK, return a 404 not found error
    pub fn ok_or_not_found<E>(&mut self, res: ResultBoxError<E>, msg: &str) -> ResultBoxError<E> {
        match res {
            Ok(e) => Ok(e),
            Err(err) => {
                println!("Error leading to 404 not found: {}", err);
                self.not_found(msg.to_string())?;
                unreachable!()
            }
        }
    }

    /// Get the path of the request
    pub fn request_path(&self) -> String {
        self.request.path().to_string()
    }

    /// Get information about the client which made the request
    pub fn api_client(&self) -> &APIClient {
        self.client.as_ref().unwrap()
    }

    /// Check if a POST parameter was present in the request or not
    pub fn has_post_parameter(&self, name: &str) -> bool {
        self.body.contains_key(name)
    }
    /// Get a post parameter
    pub fn post_parameter(&mut self, name: &str) -> ResultBoxError<&RequestValue> {
        if !self.has_post_parameter(name) {
            self.bad_request(format!("POST parameter '{}' not found in request!", name))?;
        }

        Ok(self.body.get(name).unwrap())
    }

    /// Get a post string
    pub fn post_string(&mut self, name: &str) -> ResultBoxError<String> {
        self.post_string_opt(name, 1, true)
    }

    /// Get a post string, specifying minimum length
    pub fn post_string_opt(&mut self, name: &str, min_length: usize, required: bool)
                           -> ResultBoxError<String> {
        let param = self.post_parameter(name)?;

        match (&param, required) {
            (RequestValue::String(s), _) => {
                if s.len() >= min_length {
                    Ok(s.to_string())
                } else {
                    Err(self.bad_request(format!("'{}' is too short!", name)).unwrap_err())
                }
            }

            (_, false) => Ok(String::new()),

            (_, true) =>
                Err(self.bad_request(format!("'{}' is not a string!", name)).unwrap_err()),
        }
    }

    /// Check API client tokens
    pub fn check_client_token(&mut self) -> RequestResult {
        let api_name = self.post_string("serviceName")?;
        let api_token = self.post_string("serviceToken")?;

        let client = self.ok_or_bad_request(
            api_helper::get_client(&api_name, &api_token),
            "Client not recognized!",
        )?;


        if let Some(domain) = &client.domain {
            let allowed_origin = match conf().force_https {
                true => format!("https://{}", domain),
                false => format!("http://{}", domain)
            };

            match self.request.headers().get("Referer") {
                None => self.bad_request("Unknown origin!".to_string())?,
                Some(s) => {
                    if !s.to_str()?.starts_with(&allowed_origin) {
                        self.bad_request("Use of this client is prohibited from this domain!".to_string())?;
                    }
                }
            }

            self.headers.insert("Access-Control-Allow-Origin".to_string(), allowed_origin);
        }

        self.client = Some(client);

        Ok(())
    }

    /// Check login token
    pub fn check_user_token(&mut self) -> RequestResult {
        let token = self.post_string("userToken1")?;

        // Find user
        match account_helper::get_user_by_login_token(&token, self.api_client()) {
            Ok(id) => {
                self.curr_user_id = Some(id);

                Ok(())
            }
            Err(e) => {
                println!("Error marking login tokens as invalid: {}", e);
                self.response = Some(
                    actix_web::HttpResponse::
                    build(actix_web::http::StatusCode::from_u16(412)?)
                        .json(HttpError::new(412, "Please check your login tokens!")));
                Err(e)
            }
        }
    }

    /// Check out whether a file was included in the request or not
    pub fn has_file(&self, name: &str) -> bool {
        if let Some(RequestValue::File(_)) = self.body.get(name) { true } else { false }
    }

    /// Get a file included in the request
    pub fn post_file(&mut self, name: &str) -> ResultBoxError<&PostFile> {
        if self.has_file(name) {
            if let RequestValue::File(f) = self.post_parameter(name)? {
                return Ok(f);
            }
        } else {
            self.bad_request(format!("File {} not included in request!", name))?;
        }

        unreachable!();
    }

    /// Save an image in user data directory
    pub fn save_post_image(&mut self, name: &str, folder: &str, max_w: u32, max_h: u32) -> ResultBoxError<String> {

        // Load image
        let file = self.post_file(name)?;
        let mut image = image::load_from_memory(file.buff.as_ref())?;

        if image.width() > max_w || image.height() > max_h {
            image = image.resize(max_w, max_h, image::imageops::FilterType::Nearest);
        }

        // Read EXIF information in case of JPEG image, if possible
        if let Ok(ImageFormat::Jpeg) = image::guess_format(file.buff.as_ref()) {
            let mut reader = std::io::BufReader::new(file.buff.as_ref());

            if let Ok(exif_attr) = exif::get_exif_attr_from_jpeg(&mut reader) {
                let exif_reader = exif::Reader::new();
                let exif = exif_reader.read_raw(exif_attr)?;

                if let Some(v) = exif.get_field(exif::Tag::Orientation, In::PRIMARY) {
                    match v.value.get_uint(0) {
                        Some(1) => { /* row 0 is top and column 0 is left */ }
                        //Some(2) => println!("row 0 at top and column 0 at right"),
                        Some(3) => {
                            /* row 0 at bottom and column 0 at right */
                            image = image.rotate180()
                        }
                        //Some(4) => println!("row 0 at bottom and column 0 at left"),
                        //Some(5) => println!("row 0 at left and column 0 at top"),
                        Some(6) => {
                            /* row 0 is right and column 0 is top */
                            image = image.rotate90();
                        }
                        //Some(7) => println!("row 0 at right and column 0 at bottom"),
                        Some(8) => {
                            /* row 0 is left and column 0 is bottom */
                            image = image.rotate270();
                        }
                        v => println!("Unhandled EXIF Orientation: {:?}", v),
                    };
                }
            }
        }


        // Determine image destination
        let target_user_data_folder = prepare_file_creation(&self.user_id()?, folder)?;
        let target_file_path = generate_new_user_data_file_name(target_user_data_folder.as_path(), "png")?;
        let target_sys_path = user_data_path(target_file_path.as_path());


        // Save image
        image.save_with_format(target_sys_path, ImageFormat::Png)?;

        Ok(target_file_path.to_string_lossy().to_string())
    }

    /// Get an integer included in the POST request
    pub fn post_i64(&mut self, name: &str) -> ResultBoxError<i64> {
        Ok(self.post_string(name)?.parse::<i64>()?)
    }

    /// Get an optional number in the request. If none found, return a default value
    pub fn post_u64_opt(&mut self, name: &str, default: u64) -> ResultBoxError<u64> {
        if self.has_post_parameter(name) {
            Ok(self.post_string(name)?.parse::<u64>()?)
        } else {
            Ok(default)
        }
    }

    pub fn post_u64(&mut self, name: &str) -> ResultBoxError<u64> {
        Ok(self.post_string(name)?.parse::<u64>()?)
    }

    /// Get a boolean included in a POST request
    pub fn post_bool(&mut self, name: &str) -> ResultBoxError<bool> {
        Ok(self.post_string(name)?.eq("true"))
    }

    /// Get an optional boolean included in post request
    pub fn post_bool_opt(&mut self, name: &str, default: bool) -> bool {
        self.post_bool(name).unwrap_or(default)
    }

    /// Get user ID. This function assess that a user ID is available to continue
    pub fn user_id(&self) -> ResultBoxError<UserID> {
        match self.curr_user_id.clone() {
            Some(s) => Ok(s),
            None => Err(ExecError::boxed_new("Could not get required user ID!"))
        }
    }

    /// Get a user ID, if available
    pub fn user_id_opt(&self) -> Option<UserID> {
        self.curr_user_id.clone()
    }

    /// Get current user ID, return invalid user id value if there is none
    pub fn user_id_or_invalid(&self) -> UserID {
        self.user_id_opt().unwrap_or(UserID::invalid())
    }

    /// Get user ID as a reference
    pub fn user_id_ref(&self) -> ResultBoxError<&UserID> {
        match self.curr_user_id.as_ref() {
            Some(s) => Ok(s),
            None => Err(ExecError::boxed_new("Could not get required user ID!"))
        }
    }

    /// Get an email included in the request
    pub fn post_email(&mut self, name: &str) -> ResultBoxError<String> {
        let mail = self.post_string(name)?;

        if !mailchecker::is_valid(&mail) {
            self.bad_request("Invalid email address!".to_string())?;
        }

        Ok(mail)
    }

    /// Get a list of integers included in the request
    pub fn post_numbers_list(&mut self, name: &str, min_len: usize) -> ResultBoxError<Vec<u64>> {
        let param = self.post_string_opt(name, min_len, min_len != 0)?;
        let mut list = vec![];

        for split in param.split::<&str>(",") {
            if split.is_empty() {
                continue;
            }

            list.push(split.parse::<u64>()?);
        }

        if list.len() < min_len {
            self.bad_request(format!("Not enough entries in '{}'!", name))?;
        }

        Ok(list)
    }

    /// Get the ID of a user included in a POST request
    pub fn post_user_id(&mut self, name: &str) -> ResultBoxError<UserID> {
        let user_id = UserID::new(self.post_u64(name)?);

        if user_id.id() < 1 {
            self.bad_request(format!("Invalid user specified in '{}'!", name))?;
        }

        if !user_helper::exists(&user_id)? {
            self.not_found(format!("User with ID {} not found!", user_id.id()))?;
        }

        Ok(user_id)
    }

    /// Get the ID of a friend included in a POST request
    ///
    /// *Note :* This function does not check whether the user exists or not before checking if the
    /// two users are friend because as it is not possible to be friend with a non existent person
    /// A single check is enough
    pub fn post_friend_id(&mut self, name: &str) -> ResultBoxError<UserID> {
        let friend_id = UserID::new(self.post_u64(name)?);

        if !friends_helper::are_friend(&friend_id, self.user_id_ref()?)? {
            self.forbidden("You are not friend with this person!".to_string())?;
        }

        Ok(friend_id)
    }

    /// Get a virtual directory included in a POST request
    pub fn post_virtual_directory(&mut self, name: &str) -> ResultBoxError<String> {
        let dir = self.post_string(name)?;

        if !check_virtual_directory(&dir) {
            self.bad_request(format!("Invalid virtual directory specified in '{}' !", name))?;
        }

        Ok(dir)
    }

    /// Get a string included in the request, with HTML codes removed
    pub fn post_string_without_html(&mut self, name: &str, min_length: usize, required: bool) -> ResultBoxError<String> {
        Ok(remove_html_nodes(self.post_string_opt(name, min_length, required)?.as_str()))
    }

    /// Get an optionnal string included in the request, with HTML codes removed
    pub fn post_string_without_html_opt(&mut self, name: &str, min_length: usize) -> ResultBoxError<Option<String>> {
        if !self.has_post_parameter(name) {
            Ok(None)
        } else {
            Ok(Some(remove_html_nodes(self.post_string_opt(name, min_length, true)?.as_str())))
        }
    }

    /// Get & return the ID of the conversation included in the POST request
    pub fn post_conv_id(&mut self, name: &str) -> ResultBoxError<u64> {
        let conv_id = self.post_u64(name)?;

        if !conversations_helper::does_user_belongs_to(&self.user_id()?, conv_id)? {
            self.forbidden(format!("You do not belong to conversation {} !", conv_id))?;
        }

        Ok(conv_id)
    }

    /// Get the ID
    pub fn post_group_id(&mut self, name: &str) -> ResultBoxError<GroupID> {
        let group_id = GroupID::new(self.post_u64(name)?);

        if !groups_helper::exists(&group_id)? {
            self.not_found("Specified group not found!".to_string())?;
        }

        Ok(group_id)
    }

    /// Get the ID of a group included in a request with a check for access level of current user
    pub fn post_group_id_with_access(&mut self, name: &str, min_level: GroupAccessLevel) -> ResultBoxError<GroupID> {
        let group_id = self.post_group_id(name)?;
        let access_level = groups_helper::get_access_level(&group_id, self.user_id_opt())?;

        if access_level == GroupAccessLevel::NO_ACCESS {
            self.not_found("Specified group not found!".to_string())?;
        }

        if access_level < min_level {
            self.forbidden("You do not have enough rights to perform what you intend to do on this group!".to_string())?;
        }

        Ok(group_id)
    }

    /// Get an URL included in the request
    pub fn post_url_opt(&mut self, name: &str, required: bool) -> ResultBoxError<Option<String>> {
        let url = self.post_string_opt(name, 0, required)?;

        if url.is_empty() && !required {
            Ok(None)
        } else {
            if !check_url(&url) {
                self.bad_request(format!("Invalid url specified in {} !", name))?;
            }

            Ok(Some(url))
        }
    }

    /// Get an optional virtual directory included in the request
    pub fn post_checked_virtual_directory_opt(&mut self, name: &str, target_id: u64, target_type: VirtualDirType) -> ResultBoxError<Option<String>> {
        let dir = self.post_string_opt(name, 0, false)?;

        if dir.is_empty() {
            return Ok(None);
        }

        if !virtual_directory_helper::check_availability(&dir, target_id, target_type)? {
            self.forbidden("Requested virtual directory is not available!".to_string())?;
        }

        Ok(Some(dir))
    }
}