//! The `proposals`, `proposal_comments`, `proposal_reviews` and
//! `proposal_events` tables, and the per-repository number space.

use super::{now_ms, Pool};
use sqlx::FromRow;

#[derive(Clone, Debug, FromRow)]
pub struct ProposalRow {
    pub id: i64,
    pub repo_id: i64,
    pub number: i64,
    pub title: String,
    pub body: String,
    pub author_id: Option<i64>,
    pub author: String,
    pub state: String,
    pub target: String,
    pub source_kind: String,
    pub source_repo_id: Option<i64>,
    pub source_bookmark: String,
    pub source_changes: String,
    pub projected_state: String,
    pub projected_heads: String,
    pub projected_target: String,
    pub projected_changes: String,
    pub conflicted: bool,
    pub landed_state: String,
    pub landed_by: String,
    pub landed_via: String,
    pub landed_ms: i64,
    pub created_ms: i64,
    pub updated_ms: i64,
    /// Who set it to land when its checks pass (#261); empty when off.
    #[sqlx(default)]
    pub auto_land_by: String,
    #[sqlx(default)]
    pub auto_land_ms: Option<i64>,
}

impl ProposalRow {
    pub fn projected_heads(&self) -> Vec<String> {
        self.projected_heads.split(',').filter(|s| !s.is_empty()).map(String::from).collect()
    }

    pub fn projected_changes(&self) -> Vec<String> {
        self.projected_changes.split(',').filter(|s| !s.is_empty()).map(String::from).collect()
    }

    pub fn source_changes(&self) -> Vec<String> {
        self.source_changes.split(',').filter(|s| !s.is_empty()).map(String::from).collect()
    }

    pub fn is_open(&self) -> bool {
        self.state == "open" || self.state == "draft"
    }
}

#[derive(Clone, Debug, FromRow)]
pub struct CommentRow {
    pub id: i64,
    pub proposal_id: i64,
    pub author_id: Option<i64>,
    pub author: String,
    pub body: String,
    pub path: String,
    pub anchor_change: String,
    pub anchor_index: i64,
    pub resolved: bool,
    pub created_ms: i64,
    /// The AI assistant that wrote it for the author (migration 0066),
    /// empty for the author's own comment.
    #[sqlx(default)]
    pub via: String,
}

#[derive(Clone, Debug, FromRow)]
pub struct ReviewRow {
    pub id: i64,
    pub proposal_id: i64,
    /// `None` once the author's account was deleted (its name stays).
    pub author_id: Option<i64>,
    pub author: String,
    pub verdict: String,
    pub body: String,
    pub created_ms: i64,
    /// The AI assistant that answered for the author (migration 0036),
    /// empty for the author's own review.
    #[sqlx(default)]
    pub via: String,
}

#[derive(Clone, Debug, FromRow)]
pub struct EventRow {
    pub id: i64,
    pub at_ms: i64,
    pub actor: String,
    pub event: String,
    pub detail: String,
}

/// Take the next number of a repository's shared number space.
pub async fn next_number(pool: &Pool, repo_id: i64) -> sqlx::Result<i64> {
    let mut tx = super::begin_write(pool).await?;
    sqlx::query("INSERT INTO numbers (repo_id, next) VALUES ($1, 1) ON CONFLICT DO NOTHING").bind(repo_id).execute(&mut *tx).await?;
    let n: i64 = sqlx::query_scalar("SELECT next FROM numbers WHERE repo_id = $1").bind(repo_id).fetch_one(&mut *tx).await?;
    sqlx::query("UPDATE numbers SET next = next + 1 WHERE repo_id = $1").bind(repo_id).execute(&mut *tx).await?;
    tx.commit().await?;
    Ok(n)
}

pub struct NewProposal<'a> {
    pub repo_id: i64,
    pub title: &'a str,
    pub body: &'a str,
    pub author_id: Option<i64>,
    pub author: &'a str,
    pub draft: bool,
    pub target: &'a str,
    pub source_kind: &'a str,
    pub source_repo_id: Option<i64>,
    pub source_bookmark: &'a str,
    pub source_changes: &'a str,
}

pub async fn create(pool: &Pool, p: NewProposal<'_>) -> sqlx::Result<ProposalRow> {
    let number = next_number(pool, p.repo_id).await?;
    let now = now_ms();
    sqlx::query_as(
        "INSERT INTO proposals (repo_id, number, title, body, author_id, author, state, target, source_kind, source_repo_id, source_bookmark, source_changes, created_ms, updated_ms) \
         VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14) RETURNING *",
    )
    .bind(p.repo_id)
    .bind(number)
    .bind(p.title)
    .bind(p.body)
    .bind(p.author_id)
    .bind(p.author)
    .bind(if p.draft { "draft" } else { "open" })
    .bind(p.target)
    .bind(p.source_kind)
    .bind(p.source_repo_id)
    .bind(p.source_bookmark)
    .bind(p.source_changes)
    .bind(now)
    .bind(now)
    .fetch_one(pool)
    .await
}

pub async fn get(pool: &Pool, repo_id: i64, number: i64) -> sqlx::Result<Option<ProposalRow>> {
    sqlx::query_as("SELECT * FROM proposals WHERE repo_id = $1 AND number = $2").bind(repo_id).bind(number).fetch_optional(pool).await
}

pub async fn list(pool: &Pool, repo_id: i64, states: &[&str]) -> sqlx::Result<Vec<ProposalRow>> {
    let all: Vec<ProposalRow> =
        sqlx::query_as("SELECT * FROM proposals WHERE repo_id = $1 ORDER BY number DESC").bind(repo_id).fetch_all(pool).await?;
    Ok(all.into_iter().filter(|p| states.is_empty() || states.contains(&p.state.as_str())).collect())
}

/// Open proposals of every repository, for the front page.
pub async fn open_for_author(pool: &Pool, author_id: i64) -> sqlx::Result<Vec<ProposalRow>> {
    sqlx::query_as("SELECT * FROM proposals WHERE author_id = $1 AND state IN ('open', 'draft') ORDER BY updated_ms DESC")
        .bind(author_id)
        .fetch_all(pool)
        .await
}

pub async fn set_projection(
    pool: &Pool,
    id: i64,
    state: &str,
    heads: &str,
    target_state: &str,
    changes: &str,
    conflicted: bool,
) -> sqlx::Result<()> {
    sqlx::query("UPDATE proposals SET projected_state = $1, projected_heads = $2, projected_target = $3, projected_changes = $4, conflicted = $5 WHERE id = $6")
        .bind(state)
        .bind(heads)
        .bind(target_state)
        .bind(changes)
        .bind(conflicted)
        .bind(id)
        .execute(pool)
        .await?;
    Ok(())
}

pub async fn set_state(pool: &Pool, id: i64, state: &str, landed_state: &str) -> sqlx::Result<()> {
    sqlx::query("UPDATE proposals SET state = $1, landed_state = $2, updated_ms = $3 WHERE id = $4")
        .bind(state)
        .bind(landed_state)
        .bind(now_ms())
        .bind(id)
        .execute(pool)
        .await?;
    if state == "closed" || state == "landed" {
        super::issues::finished(pool, "proposals", id).await?;
    }
    Ok(())
}

/// Mark a proposal landed, with who landed it and how.
pub async fn set_landed(pool: &Pool, id: i64, landed_state: &str, by: &str, via: &str) -> sqlx::Result<()> {
    let now = now_ms();
    sqlx::query(
        "UPDATE proposals SET state = 'landed', landed_state = $1, landed_by = $2, landed_via = $3, landed_ms = $4, updated_ms = $5 WHERE id = $6",
    )
    .bind(landed_state)
    .bind(by)
    .bind(via)
    .bind(now)
    .bind(now)
    .bind(id)
    .execute(pool)
    .await?;
    super::issues::finished(pool, "proposals", id).await
}

pub async fn edit(pool: &Pool, id: i64, title: &str, body: &str, target: &str) -> sqlx::Result<()> {
    sqlx::query("UPDATE proposals SET title = $1, body = $2, target = $3, updated_ms = $4 WHERE id = $5")
        .bind(title)
        .bind(body)
        .bind(target)
        .bind(now_ms())
        .bind(id)
        .execute(pool)
        .await?;
    Ok(())
}

pub async fn touch(pool: &Pool, id: i64) -> sqlx::Result<()> {
    sqlx::query("UPDATE proposals SET updated_ms = $1 WHERE id = $2").bind(now_ms()).bind(id).execute(pool).await?;
    Ok(())
}

pub async fn comments(pool: &Pool, proposal_id: i64) -> sqlx::Result<Vec<CommentRow>> {
    sqlx::query_as("SELECT * FROM proposal_comments WHERE proposal_id = $1 ORDER BY created_ms, id").bind(proposal_id).fetch_all(pool).await
}

pub async fn add_comment(
    pool: &Pool,
    proposal_id: i64,
    author_id: Option<i64>,
    author: &str,
    body: &str,
    path: &str,
    anchor: Option<(&str, i64)>,
) -> sqlx::Result<CommentRow> {
    let row = sqlx::query_as(
        "INSERT INTO proposal_comments (proposal_id, author_id, author, body, path, anchor_change, anchor_index, created_ms) VALUES ($1, $2, $3, $4, $5, $6, $7, $8) RETURNING *",
    )
    .bind(proposal_id)
    .bind(author_id)
    .bind(author)
    .bind(body)
    .bind(path)
    .bind(anchor.map(|a| a.0).unwrap_or(""))
    .bind(anchor.map(|a| a.1).unwrap_or(0))
    .bind(now_ms())
    .fetch_one(pool)
    .await?;
    touch(pool, proposal_id).await?;
    Ok(row)
}

/// A conversation comment an AI assistant (`via`) wrote for `author`,
/// who asked it.
pub async fn add_comment_via(
    pool: &Pool,
    proposal_id: i64,
    author_id: i64,
    author: &str,
    body: &str,
    via: &str,
) -> sqlx::Result<CommentRow> {
    let row = sqlx::query_as(
        "INSERT INTO proposal_comments (proposal_id, author_id, author, body, path, anchor_change, anchor_index, created_ms, via) VALUES ($1, $2, $3, $4, '', '', 0, $5, $6) RETURNING *",
    )
    .bind(proposal_id)
    .bind(author_id)
    .bind(author)
    .bind(body)
    .bind(now_ms())
    .bind(via)
    .fetch_one(pool)
    .await?;
    touch(pool, proposal_id).await?;
    Ok(row)
}

pub async fn set_comment_resolved(pool: &Pool, id: i64, resolved: bool) -> sqlx::Result<()> {
    sqlx::query("UPDATE proposal_comments SET resolved = $1 WHERE id = $2").bind(resolved).bind(id).execute(pool).await?;
    Ok(())
}

pub async fn reviews(pool: &Pool, proposal_id: i64) -> sqlx::Result<Vec<ReviewRow>> {
    sqlx::query_as("SELECT * FROM proposal_reviews WHERE proposal_id = $1 ORDER BY created_ms, id").bind(proposal_id).fetch_all(pool).await
}

pub async fn add_review(pool: &Pool, proposal_id: i64, author_id: i64, author: &str, verdict: &str, body: &str) -> sqlx::Result<ReviewRow> {
    add_review_via(pool, proposal_id, author_id, author, verdict, body, "").await
}

/// A review answered by an AI assistant (`via`) for `author`, who asked.
pub async fn add_review_via(
    pool: &Pool,
    proposal_id: i64,
    author_id: i64,
    author: &str,
    verdict: &str,
    body: &str,
    via: &str,
) -> sqlx::Result<ReviewRow> {
    let row = sqlx::query_as(
        "INSERT INTO proposal_reviews (proposal_id, author_id, author, verdict, body, created_ms, via) VALUES ($1, $2, $3, $4, $5, $6, $7) RETURNING *",
    )
    .bind(proposal_id)
    .bind(author_id)
    .bind(author)
    .bind(verdict)
    .bind(body)
    .bind(now_ms())
    .bind(via)
    .fetch_one(pool)
    .await?;
    touch(pool, proposal_id).await?;
    Ok(row)
}

pub async fn events(pool: &Pool, proposal_id: i64) -> sqlx::Result<Vec<EventRow>> {
    sqlx::query_as("SELECT id, at_ms, actor, event, detail FROM proposal_events WHERE proposal_id = $1 ORDER BY at_ms, id")
        .bind(proposal_id)
        .fetch_all(pool)
        .await
}

/// Whether change `hash` (its short form) already references it (#318):
/// a change is recorded once, whichever bookmarks it is pushed on.
pub async fn referenced_by(pool: &Pool, proposal_id: i64, hash: &str) -> sqlx::Result<bool> {
    let n: i64 = sqlx::query_scalar(
        "SELECT COUNT(*) FROM proposal_events WHERE proposal_id = $1 AND event = 'referenced by change' AND (detail = $2 OR detail LIKE $3)",
    )
    .bind(proposal_id)
    .bind(hash)
    .bind(format!("{hash} %"))
    .fetch_one(pool)
    .await?;
    Ok(n > 0)
}

pub async fn add_event(pool: &Pool, proposal_id: i64, actor: &str, event: &str, detail: &str) -> sqlx::Result<()> {
    sqlx::query("INSERT INTO proposal_events (proposal_id, at_ms, actor, event, detail) VALUES ($1, $2, $3, $4, $5)")
        .bind(proposal_id)
        .bind(now_ms())
        .bind(actor)
        .bind(event)
        .bind(detail)
        .execute(pool)
        .await?;
    Ok(())
}

/// Landing requirements of a repository.
#[derive(Clone, Copy, Debug, Default, FromRow)]
pub struct Requirements {
    pub required_approvals: i64,
    pub require_owners: bool,
    pub allow_conflicts: bool,
}

pub async fn requirements(pool: &Pool, repo_id: i64) -> sqlx::Result<Requirements> {
    sqlx::query_as("SELECT required_approvals, require_owners, allow_conflicts FROM repositories WHERE id = $1")
        .bind(repo_id)
        .fetch_one(pool)
        .await
}

pub async fn set_requirements(pool: &Pool, repo_id: i64, r: Requirements) -> sqlx::Result<()> {
    sqlx::query("UPDATE repositories SET required_approvals = $1, require_owners = $2, allow_conflicts = $3 WHERE id = $4")
        .bind(r.required_approvals)
        .bind(r.require_owners)
        .bind(r.allow_conflicts)
        .bind(repo_id)
        .execute(pool)
        .await?;
    Ok(())
}

// ------------------------------------------------------- review requests

/// Ask an account to review a proposal; false when it was already asked.
pub async fn request_review(pool: &Pool, proposal_id: i64, account_id: i64, by: &str) -> sqlx::Result<bool> {
    let r = sqlx::query(
        "INSERT INTO proposal_review_requests (proposal_id, account_id, requested_by, requested_ms) VALUES ($1, $2, $3, $4) ON CONFLICT DO NOTHING",
    )
    .bind(proposal_id)
    .bind(account_id)
    .bind(by)
    .bind(now_ms())
    .execute(pool)
    .await?;
    Ok(r.rows_affected() == 1)
}

/// Withdraw a request, or mark it answered; false when there was none.
pub async fn unrequest_review(pool: &Pool, proposal_id: i64, account_id: i64) -> sqlx::Result<bool> {
    let r = sqlx::query("DELETE FROM proposal_review_requests WHERE proposal_id = $1 AND account_id = $2")
        .bind(proposal_id)
        .bind(account_id)
        .execute(pool)
        .await?;
    Ok(r.rows_affected() == 1)
}

/// The usernames asked to review a proposal and not yet reviewing, in the
/// order they were asked.
pub async fn review_requests(pool: &Pool, proposal_id: i64) -> sqlx::Result<Vec<String>> {
    sqlx::query_scalar(
        "SELECT a.username FROM proposal_review_requests r JOIN accounts a ON a.id = r.account_id \
         WHERE r.proposal_id = $1 ORDER BY r.requested_ms, a.username",
    )
    .bind(proposal_id)
    .fetch_all(pool)
    .await
}

/// Set, or with `by` empty clear, landing when checks pass (#261).
pub async fn set_auto_land(pool: &Pool, id: i64, by: &str) -> sqlx::Result<()> {
    sqlx::query("UPDATE proposals SET auto_land_by = $1, auto_land_ms = $2 WHERE id = $3")
        .bind(by)
        .bind((!by.is_empty()).then(now_ms))
        .bind(id)
        .execute(pool)
        .await?;
    Ok(())
}

/// A repository's open proposals set to land when their checks pass, on
/// projected state `state`.
pub async fn auto_landing(pool: &Pool, repo_id: i64, state: &str) -> sqlx::Result<Vec<ProposalRow>> {
    sqlx::query_as(
        "SELECT * FROM proposals WHERE repo_id = $1 AND state = 'open' AND auto_land_by != '' AND projected_state = $2 ORDER BY number",
    )
    .bind(repo_id)
    .bind(state)
    .fetch_all(pool)
    .await
}