//! Projects over the API (hub spec §8.2, §12.1): the same rules as the

//! pages, through the functions they use.

use super::{caller, forbidden, not_found, ApiError, Caller};

use crate::db::projects as pdb;

use crate::web::projects as wp;

use crate::Shared;

use axum::extract::{Path, State};

use axum::http::{HeaderMap, StatusCode};

use axum::Json;

use hub_api::{Board, CardMove, CardsMove, CardsMoved, NewCard, NewProject, Project, ProjectCard, ProjectColumn, ProjectEdit};

fn project_of(app: &Shared, p: &pdb::Project) -> Project {

    Project {

        owner: p.owner.clone(),

        number: p.number,

        title: p.title.clone(),

        description: p.description.clone(),

        public: p.public,

        closed: p.closed,

        updated_ms: p.updated_ms,

        url: format!("{}/projects/{}/{}", app.config.base_url().trim_end_matches('/'), p.owner, p.number),

    }

}

fn card_of(v: &wp::CardView) -> ProjectCard {

    ProjectCard {

        id: v.card.id,

        kind: v.card.kind.clone(),

        reference: v.reference.clone(),

        title: v.title.clone(),

        state: v.state.clone(),

        labels: v.labels.iter().map(|l| l.name.clone()).collect(),

        assignees: v.assignees.clone(),

    }

}

async fn rights(app: &Shared, c: &Caller, owner: &str) -> Result<wp::Rights, ApiError> {

    wp::rights_of(app, c.account.as_ref(), owner).await?.ok_or_else(|| not_found("no such owner"))

}

/// A project the caller may see.

async fn visible(app: &Shared, c: &Caller, owner: &str, number: i64) -> Result<(wp::Rights, pdb::Project), ApiError> {

    let r = rights(app, c, owner).await?;

    let p = pdb::get(&app.db, owner, number).await?.filter(|p| p.public || r.member).ok_or_else(|| not_found("no such project"))?;

    Ok((r, p))

}

/// A project the caller may change: a write token, edit rights, and open unless `closed_ok`.

async fn changeable(

    app: &Shared,

    headers: &HeaderMap,

    owner: &str,

    number: i64,

    closed_ok: bool,

) -> Result<(Caller, pdb::Project), ApiError> {

    let c = caller(app, headers).await?;

    c.require("repo:write")?;

    let (r, p) = visible(app, &c, owner, number).await?;

    if !r.edit {

        return Err(forbidden("only the owner (or the organisation's members) may change this project"));

    }

    if p.closed && !closed_ok {

        return Err(ApiError(StatusCode::CONFLICT, "this project is closed; reopen it to change it".into()));

    }

    Ok((c, p))

}

/// A column by id or by name (case-insensitive); the first when absent.

async fn column(app: &Shared, project_id: i64, spec: Option<&str>) -> Result<pdb::Column, ApiError> {

    let cols = pdb::columns(&app.db, project_id).await?;

    let found = match spec.map(str::trim).filter(|s| !s.is_empty()) {

        None => cols.into_iter().next(),

        Some(s) => cols.into_iter().find(|c| c.id.to_string() == s || c.name.eq_ignore_ascii_case(s)),

    };

    found.ok_or_else(|| ApiError(StatusCode::BAD_REQUEST, "no such column".into()))

}

/// `GET /projects/{owner}`.

pub async fn list(State(app): State<Shared>, headers: HeaderMap, Path(owner): Path<String>) -> Result<Json<Vec<Project>>, ApiError> {

    let c = caller(&app, &headers).await?;

    let r = rights(&app, &c, &owner).await?;

    let list = pdb::of_owner(&app.db, &owner).await?;

    Ok(Json(list.iter().filter(|p| p.public || r.member).map(|p| project_of(&app, p)).collect()))

}

/// `POST /projects/{owner}`.

pub async fn create(

    State(app): State<Shared>,

    headers: HeaderMap,

    Path(owner): Path<String>,

    Json(body): Json<NewProject>,

) -> Result<(StatusCode, Json<Project>), ApiError> {

    let c = caller(&app, &headers).await?;

    c.require("repo:write")?;

    if !rights(&app, &c, &owner).await?.edit {

        return Err(forbidden("only the owner (or the organisation's members) may create projects"));

    }

    let title = body.title.trim();

    if title.is_empty() || title.chars().count() > 100 {

        return Err(ApiError(StatusCode::BAD_REQUEST, "a project needs a title of up to 100 characters".into()));

    }

    let p = pdb::create(&app.db, &owner, title, body.description.trim(), !body.private).await?;

    crate::db::accounts::audit(&app.db, c.account.as_ref(), "project.created", &format!("{owner}/{}", p.number), title).await.ok();

    Ok((StatusCode::CREATED, Json(project_of(&app, &p))))

}

/// `GET /projects/{owner}/{n}`.

pub async fn board(

    State(app): State<Shared>,

    headers: HeaderMap,

    Path((owner, number)): Path<(String, i64)>,

) -> Result<Json<Board>, ApiError> {

    let c = caller(&app, &headers).await?;

    let (_, p) = visible(&app, &c, &owner, number).await?;

    let (columns, _) = wp::board_columns(&app, c.account.as_ref(), &owner, &p).await?;

    Ok(Json(Board {

        project: project_of(&app, &p),

        columns: columns

            .iter()

            .map(|col| ProjectColumn { id: col.column.id, name: col.column.name.clone(), cards: col.cards.iter().map(card_of).collect() })

            .collect(),

    }))

}

/// `PATCH /projects/{owner}/{n}`.

pub async fn edit(

    State(app): State<Shared>,

    headers: HeaderMap,

    Path((owner, number)): Path<(String, i64)>,

    Json(body): Json<ProjectEdit>,

) -> Result<Json<Project>, ApiError> {

    let (c, p) = changeable(&app, &headers, &owner, number, true).await?;

    // A transfer (#125) first: the other fields then apply where it went.

    let (owner, number) = match body.owner.as_deref().map(str::trim).filter(|to| !to.is_empty() && *to != owner) {

        Some(to) => match wp::rights_of(&app, c.account.as_ref(), to).await? {

            Some(r) if r.edit => {

                let moved = pdb::transfer(&app.db, p.id, to).await?;

                let detail = format!("{owner}/{number} to {to}/{}", moved.number);

                crate::db::accounts::audit(&app.db, c.account.as_ref(), "project.transferred", &detail, &p.title).await.ok();

                (moved.owner, moved.number)

            }

            _ => return Err(ApiError(StatusCode::FORBIDDEN, format!("you cannot make projects under {to}"))),

        },

        None => (owner, number),

    };

    let p = pdb::get(&app.db, &owner, number).await?.unwrap_or(p);

    let title = body.title.as_deref().map(str::trim).filter(|t| !t.is_empty()).unwrap_or(&p.title).chars().take(100).collect::<String>();

    pdb::set(

        &app.db,

        p.id,

        &title,

        body.description.as_deref().map(str::trim).unwrap_or(&p.description),

        body.private.map(|x| !x).unwrap_or(p.public),

        body.closed.unwrap_or(p.closed),

    )

    .await?;

    let fresh = pdb::get(&app.db, &owner, number).await?.unwrap_or(p);

    Ok(Json(project_of(&app, &fresh)))

}

/// `GET /projects/{owner}/{n}/cards`: the cards by column, as the board

/// has them.

pub async fn cards(

    State(app): State<Shared>,

    headers: HeaderMap,

    Path((owner, number)): Path<(String, i64)>,

) -> Result<Json<Vec<ProjectColumn>>, ApiError> {

    Ok(Json(board(State(app), headers, Path((owner, number))).await?.0.columns))

}

/// `POST /projects/{owner}/{n}/cards`.

pub async fn add_card(

    State(app): State<Shared>,

    headers: HeaderMap,

    Path((owner, number)): Path<(String, i64)>,

    Json(body): Json<NewCard>,

) -> Result<(StatusCode, Json<ProjectCard>), ApiError> {

    let (c, p) = changeable(&app, &headers, &owner, number, false).await?;

    let col = column(&app, p.id, body.column.as_deref()).await?;

    let actor = c.account.as_ref().map(|a| a.username.clone()).unwrap_or_default();

    let card = match wp::add_card(&app, c.account.as_ref(), &owner, p.id, col.id, &body.reference, "", &body.note, &actor).await? {

        Ok(card) => card,

        Err(why) => return Err(ApiError(StatusCode::BAD_REQUEST, why)),

    };

    // Answer with the card as the board shows it.

    let (columns, _) = wp::board_columns(&app, c.account.as_ref(), &owner, &p).await?;

    let view = columns

        .iter()

        .flat_map(|col| col.cards.iter())

        .find(|v| v.card.id == card.id)

        .map(card_of)

        .ok_or_else(|| not_found("no such card"))?;

    Ok((StatusCode::CREATED, Json(view)))

}

/// `PATCH /projects/{owner}/{n}/cards/{id}`: move to another column.

pub async fn move_card(

    State(app): State<Shared>,

    headers: HeaderMap,

    Path((owner, number, id)): Path<(String, i64, i64)>,

    Json(body): Json<CardMove>,

) -> Result<StatusCode, ApiError> {

    let (_, p) = changeable(&app, &headers, &owner, number, false).await?;

    let col = column(&app, p.id, Some(&body.column)).await?;

    if !pdb::cards(&app.db, p.id).await?.iter().any(|c| c.id == id) {

        return Err(not_found("no such card"));

    }

    pdb::move_card(&app.db, p.id, id, col.id).await?;

    Ok(StatusCode::NO_CONTENT)

}

/// Whether `card` is the one `name` names: its id, or its issue or

/// proposal as `12`, `#12`, `name#12` or `owner/name#12`.

fn names_card(name: &str, card: &ProjectCard) -> bool {

    let name = name.trim();

    if name.is_empty() {

        return false;

    }

    if name.parse::<i64>().is_ok_and(|id| id == card.id) {

        return true;

    }

    let Some((_, number)) = card.reference.rsplit_once('#') else { return false };

    match name.rsplit_once('#') {

        None => name == number,

        Some(("", n)) => n == number,

        Some((repo, n)) => n == number && (card.reference == format!("{repo}#{n}") || card.reference.ends_with(&format!("/{repo}#{n}"))),

    }

}

/// `POST /projects/{owner}/{n}/cards/move` (#289): a column's cards to

/// another at once, with exceptions and a state filter; one audit entry.

pub async fn move_cards(

    State(app): State<Shared>,

    headers: HeaderMap,

    Path((owner, number)): Path<(String, i64)>,

    Json(body): Json<CardsMove>,

) -> Result<Json<CardsMoved>, ApiError> {

    let (c, p) = changeable(&app, &headers, &owner, number, false).await?;

    let from = column(&app, p.id, Some(&body.from)).await?;

    let to = column(&app, p.id, Some(&body.column)).await?;

    if from.id == to.id {

        return Err(ApiError(StatusCode::BAD_REQUEST, "the cards are in that column already".into()));

    }

    let (columns, _) = wp::board_columns(&app, c.account.as_ref(), &owner, &p).await?;

    let cards: Vec<ProjectCard> =

        columns.iter().filter(|col| col.column.id == from.id).flat_map(|col| col.cards.iter().map(card_of)).collect();

    let states: Vec<String> = body.state.iter().map(|s| s.trim().to_ascii_lowercase()).filter(|s| !s.is_empty()).collect();

    let (moved, kept): (Vec<ProjectCard>, Vec<ProjectCard>) = cards.into_iter().partition(|card| {

        !body.except.iter().any(|e| names_card(e, card)) && (states.is_empty() || states.iter().any(|s| card.state.eq_ignore_ascii_case(s)))

    });

    if !body.dry_run && !moved.is_empty() {

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

        pdb::move_cards(&app.db, p.id, &ids, to.id).await?;

        let detail = format!("{} card(s) from {} to {}", moved.len(), from.name, to.name);

        crate::db::accounts::audit(&app.db, c.account.as_ref(), "project.cards_moved", &format!("{owner}/{number}"), &detail).await.ok();

    }

    Ok(Json(CardsMoved { moved, kept, dry_run: body.dry_run }))

}

/// `DELETE /projects/{owner}/{n}/cards/{id}`.

pub async fn remove_card(

    State(app): State<Shared>,

    headers: HeaderMap,

    Path((owner, number, id)): Path<(String, i64, i64)>,

) -> Result<StatusCode, ApiError> {

    let (_, p) = changeable(&app, &headers, &owner, number, false).await?;

    if !pdb::cards(&app.db, p.id).await?.iter().any(|c| c.id == id) {

        return Err(not_found("no such card"));

    }

    pdb::remove_card(&app.db, p.id, id).await?;

    Ok(StatusCode::NO_CONTENT)

}