use std::{collections::HashMap, sync::Arc};

use axum::{extract::{Path, State}, Json};
use reqwest::{StatusCode};
use sea_orm::{ActiveModelTrait, ActiveValue::{NotSet, Set}, ColumnTrait, EntityTrait, JoinType, QueryFilter, QuerySelect, RelationTrait, TryIntoModel};
use serde::{Deserialize, Serialize};
use utoipa::IntoParams;

use crate::{entities::{book, book_instance, prelude::*}, routes::{auth::Claims, bal}, utils::auth::{user_is_bal_owner, user_is_book_instance_owner, user_is_owner_owner}, AppState};


#[derive(IntoParams)]
#[into_params(names("id"), parameter_in = Path)]
#[allow(dead_code)]
struct BookInstanceByIdParams(u32);

#[axum::debug_handler]
#[utoipa::path(
    get,
    path = "/book_instance/{id}",
    params(BookInstanceByIdParams),
    security(("jwt" = [])),
    responses(
        (status = OK, body = book_instance::Model, description = "Found book instance with corresponding ID in the database"),
        (status = NOT_FOUND, description = "No book instance with this id exists in the database"),
        (status = FORBIDDEN, description = "You don't own the requested book instance"),
    ),
    summary = "Get a book instance by its ID",
    description = "Get a book instance from its ID",
    tag = "book-instance-api",
)]
pub async fn get_book_instance_by_id(
    State(state): State<Arc<AppState>>,
    claims: Claims,
    Path(id): Path<u32>,
) -> (StatusCode, Json<Option<book_instance::Model>>) {
    if let Ok(Some(res)) = BookInstance::find_by_id(id).one(state.db_conn.as_ref()).await {
        if !user_is_book_instance_owner(claims.user_id, res.id, state.db_conn.as_ref()).await {
            return (StatusCode::FORBIDDEN, Json(None));
        }
        (StatusCode::OK, Json(Some(res)))
    } else {
        (StatusCode::NOT_FOUND, Json(None))
    }
}

#[derive(Deserialize, Serialize, utoipa::ToSchema)]
pub struct BookInstanceCreateParams {
    book_id: u32,
    owner_id: u32,
    bal_id: u32,
    price: f32,
}

#[axum::debug_handler]
#[utoipa::path(
    post,
    path = "/book_instance",
    request_body = BookInstanceCreateParams,
    security(("jwt" = [])),
    responses(
        (status = CREATED, body = book_instance::Model, description = "Successfully created book instance"),
        (status = FORBIDDEN, description = "You don't own the specified book instance"),
    ),
    summary = "Create a new book instance",
    description = "Create a new book instance",
    tag = "book-instance-api",
)]
pub async fn create_book_instance(
    State(state): State<Arc<AppState>>,
    claims: Claims,
    Json(instance_payload): Json<BookInstanceCreateParams>,
) -> (StatusCode, Json<Option<book_instance::Model>>) {
    if !user_is_bal_owner(claims.user_id, instance_payload.bal_id, state.db_conn.as_ref()).await {
        return (StatusCode::FORBIDDEN, Json(None));
    }

    let book_instance = book_instance::ActiveModel {
        book_id: Set(instance_payload.book_id),
        owner_id: Set(instance_payload.owner_id),
        bal_id: Set(instance_payload.bal_id),
        price: Set(instance_payload.price),
        available: Set(true),
        id: NotSet,
        sold_price: NotSet,
    };

    let b = book_instance.save(state.db_conn.as_ref()).await;
    match b {
        Err(e) => {
            log::error!(target: "api", "Error while inserting new book instance: {:#?}", e);
            (StatusCode::BAD_REQUEST, Json(None))
        },
        Ok(res) => (StatusCode::CREATED, Json(Some(res.try_into_model().expect("All fields should be set once the book instance is saved"))))
    }
}

#[derive(Deserialize, Serialize, utoipa::ToSchema)]
pub struct BookInstanceUpdateParams {
    owner_id: Option<u32>,
    price: Option<f32>,
}

#[axum::debug_handler]
#[utoipa::path(
    patch,
    path = "/book_instance/{id}",
    params(BookInstanceByIdParams),
    request_body = BookInstanceUpdateParams,
    security(("jwt" = [])),
    responses(
        (status = OK, body = book_instance::Model, description = "Successfully updated book instance"),
        (status = NOT_FOUND, description = "No book instance with specified id was found"),
        (status = FORBIDDEN, description = "You don't own the specified book instance"),
    ),
    summary = "Update a book instance",
    description = "Update a book instance",
    tag = "book-instance-api",
)]
pub async fn update_book_instance(
    State(state): State<Arc<AppState>>,
    claims: Claims,
    Path(id): Path<u32>,
    Json(instance_payload): Json<BookInstanceUpdateParams>,
) -> (StatusCode, Json<Option<book_instance::Model>>) {
    if !user_is_book_instance_owner(claims.user_id, id, state.db_conn.as_ref()).await {
        return (StatusCode::FORBIDDEN, Json(None));
    }

    if let Ok(Some(book_instance)) = BookInstance::find_by_id(id).one(state.db_conn.as_ref()).await {
        let mut book_instance: book_instance::ActiveModel = book_instance.into();
        book_instance.price = match instance_payload.price {
            None => book_instance.price,
            Some(v) => Set(v)
        };
        book_instance.owner_id = match instance_payload.owner_id {
            None => book_instance.owner_id,
            Some(v) => Set(v)
        };
        
        match book_instance.update(state.db_conn.as_ref()).await {
            Err(e) => {
                log::error!(target: "api", "Error while updating book instance from api: {:#?}", e);
                (StatusCode::INTERNAL_SERVER_ERROR, Json(None))
            },
            Ok(res) => {
                let model = res.try_into_model().expect("All fields should be set once the book instance is saved");
                (StatusCode::OK, Json(Some(model)))
            }
        }
    } else {
        (StatusCode::NOT_FOUND, Json(None))
    }
}

#[derive(Deserialize, Serialize, utoipa::ToSchema)]
pub struct BookInstanceSaleParams {
    price: f32,
}

#[axum::debug_handler]
#[utoipa::path(
    post,
    path = "/book_instance/{id}/sell",
    params(BookInstanceByIdParams),
    request_body = BookInstanceSaleParams,
    security(("jwt" = [])),
    responses(
        (status = OK, body = book_instance::Model, description = "Successfully sold book instance"),
        (status = CONFLICT, description = "The specified book instance is not available"),
        (status = NOT_FOUND, description = "No book instance with specified id was found"),
        (status = FORBIDDEN, description = "You don't own the specified book instance"),
    ),
    summary = "Sell a book instance",
    description = "Sell a book instance",
    tag = "book-instance-api",
)]
pub async fn sell_book_instance(
    State(state): State<Arc<AppState>>,
    claims: Claims,
    Path(id): Path<u32>,
    Json(instance_payload): Json<BookInstanceSaleParams>,
) -> (StatusCode, Json<Option<book_instance::Model>>) {
    if !user_is_book_instance_owner(claims.user_id, id, state.db_conn.as_ref()).await {
        return (StatusCode::FORBIDDEN, Json(None));
    }

    if let Ok(Some(book_instance)) = BookInstance::find_by_id(id).one(state.db_conn.as_ref()).await {
        if !book_instance.available {
            return (StatusCode::CONFLICT, Json(None));
        }
        let mut book_instance: book_instance::ActiveModel = book_instance.into();
        book_instance.sold_price = Set(Some(instance_payload.price));
        book_instance.available = Set(false);
        
        match book_instance.update(state.db_conn.as_ref()).await {
            Err(e) => {
                log::error!(target: "api", "Error while selling book instance from api: {:#?}", e);
                (StatusCode::INTERNAL_SERVER_ERROR, Json(None))
            },
            Ok(res) => {
                let model = res.try_into_model().expect("All fields should be set once the book instance is saved");
                (StatusCode::OK, Json(Some(model)))
            }
        }
    } else {
        (StatusCode::NOT_FOUND, Json(None))
    }
}

#[axum::debug_handler]
#[utoipa::path(
    post,
    path = "/book_instance/sell/bulk",
    request_body = HashMap<u32, f32>,
    security(("jwt" = [])),
    responses(
        (status = OK, description = "Successfully sold book instances"),
        (status = CONFLICT, description = "One of the specified book instances is not available"),
        (status = NOT_FOUND, description = "One of the specified book instances was not found"),
        (status = FORBIDDEN, description = "You don't own one of the specified book instance"),
    ),
    summary = "Sell book instances in bulk",
    description = "Sell book instances in bulk. Payload: {book_instance_id: sold_price, ...}",
    tag = "book-instance-api",
)]
pub async fn bulk_sell_book_instance(
    State(state): State<Arc<AppState>>,
    claims: Claims,
    Json(payload): Json<HashMap<u32, f32>>,
) -> StatusCode {
    // Here, we trust the client inputs valid book instances most of the time, so we already
    // allocate vector memory the size of the input map
    let mut book_instance_list: Vec<(book_instance::Model, f32)> = Vec::with_capacity(payload.len());
    
    for instance in payload {
        if let Ok(Some(book_instance)) = BookInstance::find_by_id(instance.0).one(state.db_conn.as_ref()).await {
            if !user_is_bal_owner(claims.user_id, book_instance.bal_id, state.db_conn.as_ref()).await {
                return StatusCode::FORBIDDEN
            } else if !book_instance.available {
                return StatusCode::CONFLICT
            } else {
                book_instance_list.push((book_instance, instance.1));
            }
        } else {
            return StatusCode::NOT_FOUND
        }
    }

    for instance in book_instance_list {
        let mut book_instance: book_instance::ActiveModel = instance.0.into();
        book_instance.sold_price = Set(Some(instance.1));
        book_instance.available = Set(false);
        
        let _ = book_instance.update(state.db_conn.as_ref()).await.unwrap();
    }
    StatusCode::OK
}

#[axum::debug_handler]
#[utoipa::path(
    post,
    path = "/book_instance/bulk",
    request_body = Vec<BookInstanceCreateParams>,
    security(("jwt" = [])),
    responses(
        (status = CREATED, description = "Successfully created book instances"),
        (status = FORBIDDEN, description = "You don't own at least one specified bal of the book instances sent"),
    ),
    summary = "Create new book instances in bulk",
    description = "Create new book instances in bulk",
    tag = "book-instance-api",
)]
pub async fn bulk_create_book_instance(
    State(state): State<Arc<AppState>>,
    claims: Claims,
    Json(instance_payload): Json<Vec<BookInstanceCreateParams>>,
) -> StatusCode {
    for i in &instance_payload {
        if !user_is_bal_owner(claims.user_id, i.bal_id, state.db_conn.as_ref()).await {
            return StatusCode::FORBIDDEN;
        }
    }

    let instances = instance_payload
        .into_iter()
        .map(|p| {
            book_instance::ActiveModel {
                book_id: Set(p.book_id),
                owner_id: Set(p.owner_id),
                bal_id: Set(p.bal_id),
                price: Set(p.price),
                available: Set(true),
                id: NotSet,
                sold_price: NotSet
            }
        });

    match BookInstance::insert_many(instances).exec(state.db_conn.as_ref()).await {
        Err(e) => {
            log::error!(target: "api", "Error while bulk inserting new book instances: {:#?}", e);
            StatusCode::INTERNAL_SERVER_ERROR
        },
        Ok(_) => StatusCode::CREATED
    }
}

#[derive(IntoParams)]
#[into_params(names("bal_id", "owner_id"), parameter_in = Path)]
#[allow(dead_code)]
struct BalOwnerByIdParams(u32, u32);

#[axum::debug_handler]
#[utoipa::path(
    get,
    path = "/bal/{bal_id}/owner/{owner_id}/book_instances",
    params(BalOwnerByIdParams),
    security(("jwt" = [])),
    responses(
        (status = OK, body = Vec<book_instance::Model>, description = "Found book instances in the database"),
        (status = FORBIDDEN, description = "You do not own the specified owner"),
    ),
    summary = "Get books instances from an owner in a bal",
    description = "Lists all book instances an owner has in a bal. WARNING: If the bal or owner don't exist, the endpoint will return 200/OK with an empty list",
    tag = "book-instance-api",
)]
pub async fn get_bal_owner_book_instances(
    State(state): State<Arc<AppState>>,
    claims: Claims,
    Path((bal_id, owner_id)): Path<(u32, u32)>,
) -> (StatusCode, Json<Vec<book_instance::Model>>) {
    if !user_is_owner_owner(claims.user_id, owner_id, state.db_conn.as_ref()).await {
        return (StatusCode::FORBIDDEN, Json(vec![]));
    }// If a user owns an owner, it will own the bal the owner has books in,
     // so checking for bal ownership is unnecessary
    if let Ok(res) = BookInstance::find()
        .filter(book_instance::Column::BalId.eq(bal_id))
        .filter(book_instance::Column::OwnerId.eq(owner_id))
        .all(state.db_conn.as_ref()).await
    {
        (StatusCode::OK, Json(res))
    } else {
        (StatusCode::INTERNAL_SERVER_ERROR, Json(vec![]))
    }
}

#[derive(IntoParams)]
#[into_params(names("bal_id", "ean"), parameter_in = Path)]
#[allow(dead_code)]
struct BalBookByEanParams(u32, String);

#[axum::debug_handler]
#[utoipa::path(
    get,
    path = "/bal/{bal_id}/ean/{ean}/book_instances",
    params(BalBookByEanParams),
    security(("jwt" = [])),
    responses(
        (status = OK, body = Vec<book_instance::Model>, description = "Found book instances in the database"),
        (status = FORBIDDEN, description = "You do not own the specified bal"),
    ),
    summary = "Get books instances with the specified ean in a bal",
    description = "Lists all book instances with the specified ean in a bal",
    tag = "book-instance-api",
)]
pub async fn get_bal_book_instances_by_ean(
    State(state): State<Arc<AppState>>,
    claims: Claims,
    Path((bal_id, ean)): Path<(u32, String)>,
) -> (StatusCode, Json<Vec<book_instance::Model>>) {
    if !user_is_bal_owner(claims.user_id, bal_id, state.db_conn.as_ref()).await {
        return (StatusCode::FORBIDDEN, Json(vec![]));
    }
    if let Ok(res) = BookInstance::find()
        .filter(book_instance::Column::BalId.eq(bal_id))
        .join(JoinType::InnerJoin, book_instance::Relation::Book.def())
        .filter(book::Column::Ean.eq(ean))
        .all(state.db_conn.as_ref()).await
    {
        (StatusCode::OK, Json(res))
    } else {
        (StatusCode::INTERNAL_SERVER_ERROR, Json(vec![]))
    }
}

#[derive(Deserialize, Serialize, utoipa::ToSchema)]
pub struct BookInstanceSearchParams {
    title: Option<String>,
    author: Option<String>,
}

#[derive(Serialize, utoipa::ToSchema)]
pub struct BookInstanceWithBook {
    book_instance: book_instance::Model,
    book: book::Model
}

#[axum::debug_handler]
#[utoipa::path(
    post,
    path = "/bal/{id}/search",
    params(bal::BalByIdParams),
    request_body = BookInstanceSearchParams,
    security(("jwt" = [])),
    responses(
        (status = OK, body = Vec<BookInstanceWithBook>, description = "Found book instances in the database"),
        (status = FORBIDDEN, description = "You do not own the specified bal"),
    ),
    summary = "Search a BAL for books instances",
    description = "Lists all book instances that match the requested parameters in a bal",
    tag = "book-instance-api",
)]
pub async fn search_bal_book_instances(
    State(state): State<Arc<AppState>>,
    claims: Claims,
    Path(bal_id): Path<u32>,
    Json(payload): Json<BookInstanceSearchParams>,
) -> (StatusCode, Json<Option<Vec<BookInstanceWithBook>>>) {
    if !user_is_bal_owner(claims.user_id, bal_id, state.db_conn.as_ref()).await {
        return (StatusCode::FORBIDDEN, Json(None));
    }

    let mut search_query = BookInstance::find()
        .filter(book_instance::Column::BalId.eq(bal_id))
        .filter(book_instance::Column::Available.eq(true))
        .join(JoinType::InnerJoin, book_instance::Relation::Book.def());
    if let Some(title) = payload.title {
        search_query = search_query.filter(book::Column::Title.like(format!("%{}%", title)))
    }
    if let Some(author) = payload.author {
        search_query = search_query.filter(book::Column::Author.like(format!("%{}%", author)))
    }

    if let Ok(res) = search_query.all(state.db_conn.as_ref()).await
    {
        let mut book_id_map = HashMap::new();
        for instance in &res {
            if book_id_map.get(&instance.book_id).is_none() {
                book_id_map.insert(instance.book_id, Book::find_by_id(instance.book_id).one(state.db_conn.as_ref()).await.unwrap().unwrap());   
            }
        }
        return (StatusCode::OK, Json(Some(res.iter().map(|i| BookInstanceWithBook {
            book: book_id_map.get(&i.book_id).unwrap().clone(),
            book_instance: i.clone()
        }).collect())))
    } else {
        (StatusCode::INTERNAL_SERVER_ERROR, Json(None))
    }
}