//! 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 = $1").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 ($1, $2, $3, $4, $5, $6, $7) RETURNING *",

    )

    .bind(owner)

    .bind(number)

    .bind(title)

    .bind(description)

    .bind(public)

    .bind(now)

    .bind(now)

    .fetch_one(&mut *tx)

    .await?;

    // A board here now: an old address of a transferred one gives way (#125).

    sqlx::query("DELETE FROM project_redirects WHERE owner = $1 AND number = $2").bind(owner).bind(number).execute(&mut *tx).await?;

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

        sqlx::query("INSERT INTO project_columns (project_id, name, position) VALUES ($1, $2, $3)")

            .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 = $1 ORDER BY closed, updated_ms DESC").bind(owner).fetch_all(pool).await

}

/// Move project `id` to owner `to` (#125): it takes the next number there,

/// with its columns, cards and privacy, and its old address redirects to it.

pub async fn transfer(pool: &Pool, id: i64, to: &str) -> sqlx::Result<Project> {

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

    let old: Project = sqlx::query_as("SELECT * FROM projects WHERE id = $1").bind(id).fetch_one(&mut *tx).await?;

    let number: i64 =

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

    sqlx::query("INSERT INTO project_redirects (owner, number, project_id) VALUES ($1, $2, $3) ON CONFLICT (owner, number) DO UPDATE SET project_id = excluded.project_id")

        .bind(&old.owner)

        .bind(old.number)

        .bind(id)

        .execute(&mut *tx)

        .await?;

    sqlx::query("DELETE FROM project_redirects WHERE owner = $1 AND number = $2").bind(to).bind(number).execute(&mut *tx).await?;

    let moved: Project = sqlx::query_as("UPDATE projects SET owner = $1, number = $2, updated_ms = $3 WHERE id = $4 RETURNING *")

        .bind(to)

        .bind(number)

        .bind(now_ms())

        .bind(id)

        .fetch_one(&mut *tx)

        .await?;

    tx.commit().await?;

    Ok(moved)

}

/// The project an old address (`owner`, `number`) now redirects to, after

/// a transfer (#125).

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

    sqlx::query_as("SELECT p.* FROM project_redirects r JOIN projects p ON p.id = r.project_id WHERE r.owner = $1 AND r.number = $2")

        .bind(owner)

        .bind(number)

        .fetch_optional(pool)

        .await

}

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

    sqlx::query_as("SELECT * FROM projects WHERE owner = $1 AND number = $2").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 = $1, description = $2, public = $3, closed = $4, updated_ms = $5 WHERE id = $6")

        .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 = $1").bind(id).execute(pool).await?;

    Ok(())

}

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

    sqlx::query("UPDATE projects SET updated_ms = $1 WHERE id = $2").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 = $1 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 = $1 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 = $1")

        .bind(project_id)

        .fetch_one(pool)

        .await?;

    sqlx::query("INSERT INTO project_columns (project_id, name, position) VALUES ($1, $2, $3)")

        .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 = $1 WHERE id = $2 AND project_id = $3")

        .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 = $1 WHERE id = $2").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 = $1")

        .bind(to.id)

        .fetch_one(&mut *tx)

        .await?;

    sqlx::query("UPDATE project_cards SET column_id = $1, position = position + $2 WHERE column_id = $3")

        .bind(to.id)

        .bind(base)

        .bind(column_id)

        .execute(&mut *tx)

        .await?;

    sqlx::query("DELETE FROM project_columns WHERE id = $1").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 = $1")

        .bind(c.column_id)

        .fetch_one(pool)

        .await?;

    let r = sqlx::query(

        "INSERT INTO project_cards (project_id, column_id, position, kind, repo_id, number, note, added_by, created_ms) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9) ON CONFLICT DO NOTHING",

    )

    .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 = $1 AND project_id = $2")

        .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 = $1")

        .bind(column_id)

        .fetch_one(pool)

        .await?;

    sqlx::query("UPDATE project_cards SET column_id = $1, position = $2 WHERE id = $3 AND project_id = $4")

        .bind(column_id)

        .bind(pos)

        .bind(card_id)

        .bind(project_id)

        .execute(pool)

        .await?;

    touch(pool, project_id).await

}

/// Move `card_ids`, in that order, to the end of `column_id`, all or none

/// (#289).

pub async fn move_cards(pool: &Pool, project_id: i64, card_ids: &[i64], column_id: i64) -> sqlx::Result<()> {

    let mut tx = pool.begin().await?;

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

        .bind(column_id)

        .fetch_one(&mut *tx)

        .await?;

    for (i, id) in card_ids.iter().enumerate() {

        sqlx::query("UPDATE project_cards SET column_id = $1, position = $2 WHERE id = $3 AND project_id = $4")

            .bind(column_id)

            .bind(pos + i as i64)

            .bind(id)

            .bind(project_id)

            .execute(&mut *tx)

            .await?;

    }

    sqlx::query("UPDATE projects SET updated_ms = $1 WHERE id = $2").bind(now_ms()).bind(project_id).execute(&mut *tx).await?;

    tx.commit().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 = $1 AND project_id = $2")

        .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 = $1 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 = $1 WHERE id = $2").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 = $1 AND project_id = $2").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 = $1 AND c.number = $2 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 = $1").bind(pid).fetch_optional(pool).await? {

            out.push((p, col));

        }

    }

    Ok(out)

}