//! Projects, their columns and cards (hub spec §8.2).

use super::{now_ms, Pool};

use sqlx::FromRow;

#[derive(Clone, Debug, FromRow)]

pub struct Project {

    pub id: i64,

    pub owner: String,

    pub number: i64,

    pub title: String,

    pub description: String,

    pub public: bool,

    pub closed: bool,

    pub created_ms: i64,

    pub updated_ms: i64,

}

#[derive(Clone, Debug, FromRow)]

pub struct Column {

    pub id: i64,

    pub project_id: i64,

    pub name: String,

    pub position: i64,

}

#[derive(Clone, Debug, FromRow)]

pub struct Card {

    pub id: i64,

    pub project_id: i64,

    pub column_id: i64,

    pub position: i64,

    pub kind: String,

    pub repo_id: Option<i64>,

    pub number: Option<i64>,

    pub note: String,

    pub added_by: String,

    pub created_ms: i64,

}

pub const DEFAULT_COLUMNS: [&str; 3] = ["Backlog", "Doing", "Done"];

pub async fn create(pool: &Pool, owner: &str, title: &str, description: &str, public: bool) -> sqlx::Result<Project> {

    let mut tx = super::begin_write(pool).await?;

    let number: i64 =

        sqlx::query_scalar("SELECT COALESCE(MAX(number), 0) + 1 FROM projects WHERE owner = ?").bind(owner).fetch_one(&mut *tx).await?;

    let now = now_ms();

    let p: Project = sqlx::query_as(

        "INSERT INTO projects (owner, number, title, description, public, created_ms, updated_ms) VALUES (?, ?, ?, ?, ?, ?, ?) RETURNING *",

    )

    .bind(owner)

    .bind(number)

    .bind(title)

    .bind(description)

    .bind(public)

    .bind(now)

    .bind(now)

    .fetch_one(&mut *tx)

    .await?;

    for (i, name) in DEFAULT_COLUMNS.iter().enumerate() {

        sqlx::query("INSERT INTO project_columns (project_id, name, position) VALUES (?, ?, ?)")

            .bind(p.id)

            .bind(name)

            .bind(i as i64)

            .execute(&mut *tx)

            .await?;

    }

    tx.commit().await?;

    Ok(p)

}

pub async fn of_owner(pool: &Pool, owner: &str) -> sqlx::Result<Vec<Project>> {

    sqlx::query_as("SELECT * FROM projects WHERE owner = ? ORDER BY closed, updated_ms DESC").bind(owner).fetch_all(pool).await

}

pub async fn get(pool: &Pool, owner: &str, number: i64) -> sqlx::Result<Option<Project>> {

    sqlx::query_as("SELECT * FROM projects WHERE owner = ? AND number = ?").bind(owner).bind(number).fetch_optional(pool).await

}

pub async fn set(pool: &Pool, id: i64, title: &str, description: &str, public: bool, closed: bool) -> sqlx::Result<()> {

    sqlx::query("UPDATE projects SET title = ?, description = ?, public = ?, closed = ?, updated_ms = ? WHERE id = ?")

        .bind(title)

        .bind(description)

        .bind(public)

        .bind(closed)

        .bind(now_ms())

        .bind(id)

        .execute(pool)

        .await?;

    Ok(())

}

pub async fn delete(pool: &Pool, id: i64) -> sqlx::Result<()> {

    sqlx::query("DELETE FROM projects WHERE id = ?").bind(id).execute(pool).await?;

    Ok(())

}

async fn touch(pool: &Pool, id: i64) -> sqlx::Result<()> {

    sqlx::query("UPDATE projects SET updated_ms = ? WHERE id = ?").bind(now_ms()).bind(id).execute(pool).await?;

    Ok(())

}

pub async fn columns(pool: &Pool, project_id: i64) -> sqlx::Result<Vec<Column>> {

    sqlx::query_as("SELECT * FROM project_columns WHERE project_id = ? ORDER BY position, id").bind(project_id).fetch_all(pool).await

}

pub async fn cards(pool: &Pool, project_id: i64) -> sqlx::Result<Vec<Card>> {

    sqlx::query_as("SELECT * FROM project_cards WHERE project_id = ? ORDER BY position, id").bind(project_id).fetch_all(pool).await

}

pub async fn add_column(pool: &Pool, project_id: i64, name: &str) -> sqlx::Result<()> {

    let pos: i64 = sqlx::query_scalar("SELECT COALESCE(MAX(position), -1) + 1 FROM project_columns WHERE project_id = ?")

        .bind(project_id)

        .fetch_one(pool)

        .await?;

    sqlx::query("INSERT INTO project_columns (project_id, name, position) VALUES (?, ?, ?)")

        .bind(project_id)

        .bind(name)

        .bind(pos)

        .execute(pool)

        .await?;

    touch(pool, project_id).await

}

pub async fn rename_column(pool: &Pool, project_id: i64, column_id: i64, name: &str) -> sqlx::Result<()> {

    sqlx::query("UPDATE project_columns SET name = ? WHERE id = ? AND project_id = ?")

        .bind(name)

        .bind(column_id)

        .bind(project_id)

        .execute(pool)

        .await?;

    touch(pool, project_id).await

}

/// Swap a column with its neighbour (`-1` left, `1` right).

pub async fn shift_column(pool: &Pool, project_id: i64, column_id: i64, by: i64) -> sqlx::Result<()> {

    let cols = columns(pool, project_id).await?;

    let Some(i) = cols.iter().position(|c| c.id == column_id) else { return Ok(()) };

    let j = i as i64 + by;

    if j < 0 || j as usize >= cols.len() {

        return Ok(());

    }

    let mut ids: Vec<i64> = cols.iter().map(|c| c.id).collect();

    ids.swap(i, j as usize);

    for (pos, id) in ids.iter().enumerate() {

        sqlx::query("UPDATE project_columns SET position = ? WHERE id = ?").bind(pos as i64).bind(id).execute(pool).await?;

    }

    touch(pool, project_id).await

}

/// Remove a column; its cards go to the first remaining column. The last column stays.

pub async fn remove_column(pool: &Pool, project_id: i64, column_id: i64) -> sqlx::Result<bool> {

    let cols = columns(pool, project_id).await?;

    let Some(to) = cols.iter().find(|c| c.id != column_id) else { return Ok(false) };

    if !cols.iter().any(|c| c.id == column_id) {

        return Ok(false);

    }

    let mut tx = super::begin_write(pool).await?;

    let base: i64 = sqlx::query_scalar("SELECT COALESCE(MAX(position), -1) + 1 FROM project_cards WHERE column_id = ?")

        .bind(to.id)

        .fetch_one(&mut *tx)

        .await?;

    sqlx::query("UPDATE project_cards SET column_id = ?, position = position + ? WHERE column_id = ?")

        .bind(to.id)

        .bind(base)

        .bind(column_id)

        .execute(&mut *tx)

        .await?;

    sqlx::query("DELETE FROM project_columns WHERE id = ?").bind(column_id).execute(&mut *tx).await?;

    tx.commit().await?;

    touch(pool, project_id).await?;

    Ok(true)

}

pub struct NewCard<'a> {

    pub column_id: i64,

    pub kind: &'a str,

    pub repo_id: Option<i64>,

    pub number: Option<i64>,

    pub note: &'a str,

    pub added_by: &'a str,

}

/// Add a card at the bottom of a column; `Ok(false)` when that issue or

/// proposal is already on the project.

pub async fn add_card(pool: &Pool, project_id: i64, c: NewCard<'_>) -> sqlx::Result<bool> {

    let pos: i64 = sqlx::query_scalar("SELECT COALESCE(MAX(position), -1) + 1 FROM project_cards WHERE column_id = ?")

        .bind(c.column_id)

        .fetch_one(pool)

        .await?;

    let r = sqlx::query(

        "INSERT OR IGNORE INTO project_cards (project_id, column_id, position, kind, repo_id, number, note, added_by, created_ms) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)",

    )

    .bind(project_id)

    .bind(c.column_id)

    .bind(pos)

    .bind(c.kind)

    .bind(c.repo_id)

    .bind(c.number)

    .bind(c.note)

    .bind(c.added_by)

    .bind(now_ms())

    .execute(pool)

    .await?;

    touch(pool, project_id).await?;

    Ok(r.rows_affected() == 1)

}

/// Move a card to the bottom of another column of the same project.

pub async fn move_card(pool: &Pool, project_id: i64, card_id: i64, column_id: i64) -> sqlx::Result<()> {

    let ok: i64 = sqlx::query_scalar("SELECT COUNT(*) FROM project_columns WHERE id = ? AND project_id = ?")

        .bind(column_id)

        .bind(project_id)

        .fetch_one(pool)

        .await?;

    if ok == 0 {

        return Ok(());

    }

    let pos: i64 = sqlx::query_scalar("SELECT COALESCE(MAX(position), -1) + 1 FROM project_cards WHERE column_id = ?")

        .bind(column_id)

        .fetch_one(pool)

        .await?;

    sqlx::query("UPDATE project_cards SET column_id = ?, position = ? WHERE id = ? AND project_id = ?")

        .bind(column_id)

        .bind(pos)

        .bind(card_id)

        .bind(project_id)

        .execute(pool)

        .await?;

    touch(pool, project_id).await

}

/// Swap a card with its neighbour in its column (`-1` up, `1` down).

pub async fn shift_card(pool: &Pool, project_id: i64, card_id: i64, by: i64) -> sqlx::Result<()> {

    let Some(card): Option<Card> = sqlx::query_as("SELECT * FROM project_cards WHERE id = ? AND project_id = ?")

        .bind(card_id)

        .bind(project_id)

        .fetch_optional(pool)

        .await?

    else {

        return Ok(());

    };

    let col: Vec<Card> = sqlx::query_as("SELECT * FROM project_cards WHERE column_id = ? ORDER BY position, id")

        .bind(card.column_id)

        .fetch_all(pool)

        .await?;

    let Some(i) = col.iter().position(|c| c.id == card_id) else { return Ok(()) };

    let j = i as i64 + by;

    if j < 0 || j as usize >= col.len() {

        return Ok(());

    }

    let mut ids: Vec<i64> = col.iter().map(|c| c.id).collect();

    ids.swap(i, j as usize);

    for (pos, id) in ids.iter().enumerate() {

        sqlx::query("UPDATE project_cards SET position = ? WHERE id = ?").bind(pos as i64).bind(id).execute(pool).await?;

    }

    touch(pool, project_id).await

}

pub async fn remove_card(pool: &Pool, project_id: i64, card_id: i64) -> sqlx::Result<()> {

    sqlx::query("DELETE FROM project_cards WHERE id = ? AND project_id = ?").bind(card_id).bind(project_id).execute(pool).await?;

    touch(pool, project_id).await

}

/// The projects (and column names) an issue or proposal is on.

pub async fn placements(pool: &Pool, repo_id: i64, number: i64) -> sqlx::Result<Vec<(Project, String)>> {

    let rows: Vec<(i64, String)> = sqlx::query_as(

        "SELECT c.project_id, col.name FROM project_cards c JOIN project_columns col ON col.id = c.column_id WHERE c.repo_id = ? AND c.number = ? AND c.kind <> 'note'",

    )

    .bind(repo_id)

    .bind(number)

    .fetch_all(pool)

    .await?;

    let mut out = Vec::new();

    for (pid, col) in rows {

        if let Some(p) = sqlx::query_as::<_, Project>("SELECT * FROM projects WHERE id = ?").bind(pid).fetch_optional(pool).await? {

            out.push((p, col));

        }

    }

    Ok(out)

}