use axum::{
    Router,
    extract::{State, path::Path},
    http::HeaderMap,
    response::IntoResponse,
    routing::{delete, get, post, put},
};
use axum_extra::extract::Form;
use cache_bust::asset;
use chrono::DateTime;
use maud::{Markup, PreEscaped, html};
use serde::Deserialize;
use serde_json::json;
use slug::slugify;
use sqlx::{QueryBuilder, Sqlite};

use super::Layout;
use super::home::journal_section;
use crate::db::DbId;
use crate::models::user::AuthSession;
use crate::models::{HydratedContact, JournalEntry};
use crate::{AppError, AppState};

#[derive(serde::Serialize, Debug)]
pub struct Address {
    pub id: DbId,
    pub contact_id: DbId,
    pub label: Option<String>,
    pub value: String,
}

#[derive(serde::Serialize, Debug)]
pub struct Group {
    pub contact_id: DbId,
    pub name: String,
    pub slug: String,
}

pub fn router() -> Router<AppState> {
    Router::new()
        .route("/contact/new", post(self::post::contact))
        .route("/contact/{contact_id}", get(self::get::contact))
        .route("/contact/{contact_id}", put(self::put::contact))
        .route("/contact/{contact_id}", delete(self::delete::contact))
        .route("/contact/{contact_id}/edit", get(self::get::contact_edit))
}

fn human_delta(delta: &chrono::TimeDelta) -> String {
    if delta.num_days() == 0 {
        return "today".to_string();
    }

    let mut result = "in ".to_string();
    let mut rem = delta.clone();
    if rem.num_days().abs() >= 7 {
        let weeks = rem.num_days() / 7;
        rem -= chrono::TimeDelta::days(weeks * 7);
        result.push_str(&format!("{}w ", weeks));
    }
    if rem.num_days().abs() > 0 {
        result.push_str(&format!("{}d ", rem.num_days()));
    }
    result.trim().to_string()
}

mod get {
    use super::*;

    pub async fn contact(
        auth_session: AuthSession,
        State(state): State<AppState>,
        Path(contact_id): Path<u32>,
        layout: Layout,
    ) -> Result<Markup, AppError> {
        let pool = &state.db(&auth_session.user.unwrap()).pool;
        let contact: HydratedContact = sqlx::query_as(
            "select id, birthday, manually_freshened_at, (
            select string_agg(name,'\x1c' order by sort)
            from names where contact_id = c.id
        ) as names
        from contacts c
        where c.id = $1",
        )
        .bind(contact_id)
        .fetch_one(pool)
        .await?;

        let entries: Vec<JournalEntry> = sqlx::query_as(
            "select distinct j.id, j.value, j.date from journal_entries j
            join journal_mentions cm on j.id = cm.entry_id
            where cm.url = '/contact/'||$1 or cm.url in (
                select '/group/'||slug from groups
                where contact_id = $1
            )
            order by j.date desc
            ",
        )
        .bind(contact_id)
        .fetch_all(pool)
        .await?;

        let addresses: Vec<Address> = sqlx::query_as!(
            Address,
            "select * from addresses where contact_id = $1",
            contact_id
        )
        .fetch_all(pool)
        .await?;

        let groups: Vec<Group> = sqlx::query_as!(
            Group,
            "select * from groups where contact_id = $1",
            contact_id
        )
        .fetch_all(pool)
        .await?;

        let text_body: Option<String> =
            sqlx::query!("select text_body from contacts where id = $1", contact_id)
                .fetch_one(pool)
                .await?
                .text_body;

        Ok(layout.render(
            Some(vec![asset!("contact.css"), asset!("journal.css")]),
            html! {
                a href=(format!("/contact/{}/edit", contact_id)) { "Edit" }

                div id="fields" {
                    label { @if contact.names.len() > 1 { "names" } @else { "name" }}
                    div {
                        @for name in &contact.names {
                            div { (name) }
                        }
                    }
                    @if let Some(bday) = &contact.birthday {
                        label { "birthday" }
                        div {
                            (bday.to_string())
                            @if let Some(delta) = &bday.until_next() {
                                " ("
                                (human_delta(delta))
                                @if let Some(age) = &bday.age() {
                                    ", turning " (age + 1)
                                }
                                ")"
                            }

                        }
                    }
                    label { "freshened" }
                    div {
                        @if let Some(when) = &contact.manually_freshened_at {
                            (when.date_naive().to_string())
                        } @else {
                            "(never)"
                        }
                    }
                    @if addresses.len() == 1 {
                        label { "address" }
                        #addresses {
                            .label {}
                            .value { (addresses[0].value) }
                        }
                    } @else if addresses.len() > 0 {
                        label { "addresses" }
                        #addresses {
                            @for address in addresses {
                                @let lbl = address.label.unwrap_or(String::new());
                                .label data-is-empty=(lbl.len() == 0) {
                                    (lbl)
                                }
                                .value { (address.value) }
                            }
                        }
                    }

                    @if groups.len() > 0 {
                        label { "in groups" }
                        #groups {
                            @for group in groups {
                                a .group href=(format!("/group/{}", group.slug)) {
                                    (group.name)
                                }
                            }
                        }
                    }
                }


                @if let Some(text_body) = text_body {
                    @if text_body.len() > 0 {
                        #text_body { (PreEscaped(markdown::to_html(&text_body))) }
                    }
                }

                (journal_section(pool, &entries).await?)
            },
        ))
    }

    pub async fn contact_edit(
        auth_session: AuthSession,
        State(state): State<AppState>,
        Path(contact_id): Path<u32>,
        layout: Layout,
    ) -> Result<Markup, AppError> {
        let pool = &state.db(&auth_session.user.unwrap()).pool;
        let contact: HydratedContact = sqlx::query_as(
            "select id, birthday, manually_freshened_at, (
            select string_agg(name,'\x1c' order by sort)
            from names where contact_id = c.id
        ) as names, (
            select jes.date from journal_entries jes
            join journal_mentions cms on cms.entry_id = jes.id
            where cms.url = '/contact/'||c.id
            order by jes.date desc limit 1
        ) as last_mention_date from contacts c
        where c.id = $1",
        )
        .bind(contact_id)
        .fetch_one(pool)
        .await?;

        let addresses: Vec<Address> = sqlx::query_as!(
            Address,
            "select * from addresses where contact_id = $1",
            contact_id
        )
        .fetch_all(pool)
        .await?;

        let cid_url = format!("/contact/{}", contact.id);
        let mfresh_str = contact
            .manually_freshened_at
            .clone()
            .map_or("".to_string(), |m| m.to_rfc3339());

        let groups: Vec<String> = sqlx::query_as!(
            Group,
            "select * from groups where contact_id = $1",
            contact_id
        )
        .fetch_all(pool)
        .await?
        .into_iter()
        .map(|group| group.name)
        .collect();

        let text_body: String =
            sqlx::query!("select text_body from contacts where id = $1", contact_id)
                .fetch_one(pool)
                .await?
                .text_body
                .unwrap_or(String::new());

        Ok(layout.render(Some(vec![asset!("contact.css")]), html! {
        form hx-ext="response-targets" {
            div {
                input type="button" value="Save" hx-put=(cid_url) hx-target-error="#error";
                input type="button" value="Delete" hx-delete=(cid_url) hx-target-error="#error";
                div #error;
            }

            div #fields {
                label { @if contact.names.len() > 1 { "names" } @else { "name" }}
                div #names x-data=(format!("{{ names: {:?}, new_name: '' }}", &contact.names)) {
                    template x-for="(name, idx) in names" {
                        div {
                            input name="name" x-model="name";
                            input type="button" value="×" x-bind:disabled="idx == 0" x-on:click="names.splice(idx, 1)";
                            input type="button" value="↑" x-bind:disabled="idx == 0" x-on:click="[names[idx-1], names[idx]] = [names[idx], names[idx-1]]";
                            input type="button" value="↓" x-bind:disabled="idx == names.length - 1" x-on:click="[names[idx+1], names[idx]] = [names[idx], names[idx+1]]";
                        }
                    }
                    div {
                        input name="name" x-model="new_name" placeholder="New name";
                        input type="button" value="Add" x-on:click="names.push(new_name); new_name = ''";
                    }
                }
                label { "birthday" }
                div {
                    input name="birthday" value=(contact.birthday.clone().map_or("".to_string(), |b| b.serialize()));
                    span .hint { code { "(yyyy|--)mmdd" } " or free text" }
                }
                label { "freshened" }
                div x-data=(json!({ "date": mfresh_str })) {
                    input type="hidden" name="manually_freshened_at" x-model="date";
                    span x-text="date.length ? date.split('T')[0] : '(never)'" {}
                    input type="button" value="Mark fresh now" x-on:click="date = new Date().toISOString()";
                }
                label { "addresses" }
                div x-data=(json!({ "addresses": addresses, "new_label": "", "new_address": "" })) {
                    template x-for="(address, index) in addresses" x-bind:key="index" {
                        .address-input {
                            input name="address_label" x-show="addresses.length" x-model="address.label" placeholder="label";
                            .grow-wrap x-bind:data-replicated-value="address.value" {
                                textarea name="address_value" x-model="address.value" placeholder="address" {}
                            }
                        }
                    }
                    .address-input {
                        input x-show="addresses.length" name="address_label" x-model="new_label" placeholder="label";
                        .grow-wrap x-bind:data-replicated-value="new_address" {
                            textarea name="address_value" x-model="new_address" placeholder="new address" {}
                        }
                    }
                    input type="button" value="Add" x-on:click="addresses.push({ label: new_label, value: new_address }); new_label = ''; new_address = ''";
                }
                label { "groups" }
                #groups x-data=(json!({ "groups": groups, "new_group": "" })) {
                    template x-for="(group, index) in groups" x-bind:key="index" {
                        input name="group" x-model="group" placeholder="group name";
                    }
                    input name="group" x-model="new_group" placeholder="group name";
                    input type="button" value="Add" x-on:click="groups.push(new_group); new_group = ''";
                }
            }
            div #text_body {
                div { "Free text (supports markdown)" }
                .grow-wrap data-replicated-value=(text_body) {
                    textarea name="text_body"
                    onInput="this.parentNode.dataset.replicatedValue = this.value"
                    { (text_body) }
                }
            }
        }
    }))
    }
}

mod post {
    use super::*;

    pub async fn contact(
        auth_session: AuthSession,
        State(state): State<AppState>,
    ) -> Result<impl IntoResponse, AppError> {
        let user = auth_session.user.unwrap();
        let pool = &state.db(&user).pool;

        let contact_id: (u32,) =
            sqlx::query_as("insert into contacts (birthday) values (null) returning id")
                .fetch_one(pool)
                .await?;

        let mut headers = HeaderMap::new();
        headers.insert(
            "HX-Redirect",
            format!("/contact/{}/edit", contact_id.0).parse()?,
        );
        Ok((headers, "ok"))
    }
}

mod put {
    use super::*;

    #[derive(Deserialize)]
    pub struct PutContact {
        name: Option<Vec<String>>,
        birthday: String,
        manually_freshened_at: String,
        address_label: Option<Vec<String>>,
        address_value: Option<Vec<String>>,
        group: Option<Vec<String>>,
        text_body: String,
    }

    pub async fn contact(
        auth_session: AuthSession,
        State(state): State<AppState>,
        Path(contact_id): Path<DbId>,
        Form(payload): Form<PutContact>,
    ) -> Result<impl IntoResponse, AppError> {
        let user = auth_session.user.unwrap();
        let pool = &state.db(&user).pool;

        let birthday = if payload.birthday.is_empty() {
            None
        } else {
            Some(payload.birthday)
        };

        let manually_freshened_at = if payload.manually_freshened_at.is_empty() {
            None
        } else {
            Some(
                DateTime::parse_from_str(&payload.manually_freshened_at, "%+")
                    .map_err(|_| anyhow::Error::msg("Could not parse freshened-at string"))?
                    .to_utc()
                    .to_rfc3339(),
            )
        };

        let text_body = if payload.text_body.is_empty() {
            None
        } else {
            Some(payload.text_body)
        };

        sqlx::query!(
            "update contacts set (birthday, manually_freshened_at, text_body) = ($1, $2, $3) where id = $4",
            birthday,
            manually_freshened_at,
            text_body,
            contact_id
        )
        .execute(pool)
        .await?;

        // these blocks are not in functions because payload gets progressively
        // partially moved as we handle each field and i don't want to deal with it

        {
            // update addresses
            let new_addresses = payload.address_value.clone().map(|values| {
                let labels: Vec<String> = if values.len() == 1 {
                    vec![String::new()]
                } else {
                    payload.address_label.clone().unwrap_or(vec![])
                };

                labels
                    .into_iter()
                    .zip(values)
                    .filter(|(_, val)| val.len() > 0)
                    .collect::<Vec<(String, String)>>()
            });
            let new_addresses = new_addresses.unwrap_or(vec![]);

            let old_addresses: Vec<(String, String)> =
                sqlx::query_as("select label, value from addresses where contact_id = $1")
                    .bind(contact_id)
                    .fetch_all(pool)
                    .await?;

            if new_addresses != old_addresses {
                sqlx::query!("delete from addresses where contact_id = $1", contact_id)
                    .execute(pool)
                    .await?;

                // trailing space in query intentional
                QueryBuilder::new("insert into addresses (contact_id, label, value) ")
                    .push_values(new_addresses, |mut b, (label, value)| {
                        b.push_bind(contact_id).push_bind(label).push_bind(value);
                    })
                    .build()
                    .persistent(false)
                    .execute(pool)
                    .await?;
            }
        }

        {
            // recalculate all contact mentions and name trie if name-list changed
            let new_names: Vec<String> = payload
                .name
                .unwrap_or(vec![])
                .into_iter()
                .filter(|n| n.len() > 0)
                .collect();
            let old_names: Vec<(String,)> =
                sqlx::query_as("select name from names where contact_id = $1")
                    .bind(contact_id)
                    .fetch_all(pool)
                    .await?;
            let old_names: Vec<String> = old_names.into_iter().map(|(s,)| s).collect();

            if old_names != new_names {
                // delete and regen *all* journal mentions, not just the ones for the
                // current user, since changing *this* user's names can change, *globally*,
                // which names have n=1 and thus are eligible for mentioning
                sqlx::query!(
                    "delete from journal_mentions; delete from names where contact_id = $1",
                    contact_id
                )
                .execute(pool)
                .await?;

                let mut recalc_counts: QueryBuilder<Sqlite> = QueryBuilder::new(
                    "select name, contact_id from (
            select name, contact_id, count(name) as ct from names where name in (",
                );
                let mut name_list = recalc_counts.separated(", ");
                for name in &old_names {
                    name_list.push_bind(name);
                }

                if !new_names.is_empty() {
                    for name in &new_names {
                        name_list.push_bind(name.clone());
                    }

                    let mut name_insert: QueryBuilder<Sqlite> =
                        QueryBuilder::new("insert into names (contact_id, sort, name) ");
                    name_insert.push_values(
                        new_names.iter().enumerate(),
                        |mut builder, (sort, name)| {
                            builder
                                .push_bind(contact_id)
                                .push_bind(DbId::try_from(sort).unwrap())
                                .push_bind(name);
                        },
                    );
                    name_insert.build().persistent(false).execute(pool).await?;
                }

                name_list.push_unseparated(") group by name) where ct = 1");
                let recalc_names: Vec<(String, DbId)> = recalc_counts
                    .build_query_as()
                    .persistent(false)
                    .fetch_all(pool)
                    .await?;

                {
                    let trie_mutex = state.contact_search(&user);
                    let mut trie = trie_mutex.write().unwrap();
                    for name in &old_names {
                        trie.remove(name);
                    }

                    for name in recalc_names {
                        trie.insert(name.0, format!("/contact/{}", name.1));
                    }
                }
            }

            let new_groups: Vec<String> = payload
                .group
                .unwrap_or(vec![])
                .into_iter()
                .filter(|n| n.len() > 0)
                .collect();
            let old_groups: Vec<(String,)> =
                sqlx::query_as("select name from groups where contact_id = $1")
                    .bind(contact_id)
                    .fetch_all(pool)
                    .await?;
            let old_groups: Vec<String> = old_groups.into_iter().map(|(s,)| s).collect();

            if new_groups != old_groups {
                sqlx::query!(
                    "delete from journal_mentions; delete from groups where contact_id = $1",
                    contact_id
                )
                .execute(pool)
                .await?;

                QueryBuilder::new("insert into groups (contact_id, name, slug) ")
                    .push_values(&new_groups, |mut b, name| {
                        b.push_bind(contact_id)
                            .push_bind(name)
                            .push_bind(slugify(name));
                    })
                    .build()
                    .persistent(false)
                    .execute(pool)
                    .await?;

                {
                    let trie_mutex = state.contact_search(&user);
                    let mut trie = trie_mutex.write().unwrap();
                    for name in &old_groups {
                        // TODO i think we care about group name vs contact name counts,
                        // otherwise this will cause a problem (or we want to disallow
                        // setting group names that are contact names or vice versa?)
                        trie.remove(name);
                    }

                    for group in &new_groups {
                        trie.insert(group.clone(), format!("/group/{}", slugify(group)));
                    }
                }
            }

            if new_names != old_names || new_groups != old_groups {
                let journal_entries: Vec<JournalEntry> =
                    sqlx::query_as("select * from journal_entries")
                        .fetch_all(pool)
                        .await?;

                for entry in journal_entries {
                    entry
                        .insert_mentions(state.contact_search(&user), pool)
                        .await?;
                }
            }
        }

        let mut headers = HeaderMap::new();
        headers.insert("HX-Redirect", format!("/contact/{}", contact_id).parse()?);
        Ok((headers, "ok"))
    }
}
mod delete {
    use super::*;
    pub async fn contact(
        auth_session: AuthSession,
        State(state): State<AppState>,
        Path(contact_id): Path<u32>,
    ) -> Result<impl IntoResponse, AppError> {
        let user = auth_session.user.unwrap();
        let pool = &state.db(&user).pool;

        sqlx::query(
            "delete from journal_mentions where contact_id = $1;
        delete from names where contact_id = $1;
        delete from contacts where id = $1;",
        )
        .bind(contact_id)
        .execute(pool)
        .await?;

        let mut headers = HeaderMap::new();
        headers.insert("HX-Redirect", "/".parse()?);
        Ok((headers, "ok"))
    }
}