//! Read-only expansion and atomic activation for one workspace.
use crate::{
    domain::*,
    engine,
    error::{Result, ensure},
    generation::{self, Issue, Rule, Variable},
    providers,
    store::{Store, WorkspaceRecord},
};
use chrono::{Duration, Utc};
use serde::Deserialize;
use serde_json::{Value, json};
use uuid::Uuid;
#[derive(Debug, Clone, Deserialize)]
pub struct Draft {
    pub revision: i64,
    pub variables: Vec<Variable>,
    pub rules: Vec<Rule>,
    #[serde(default)]
    pub route_position: usize,
    #[serde(default)]
    pub review_id: Option<String>,
}
struct Prepared {
    report: Value,
    record: WorkspaceRecord,
    issues: Vec<Issue>,
    review: String,
}
async fn prepare(db: &Store, actor: Uuid, workspace: Uuid, draft: &Draft) -> Result<Prepared> {
    let mut record = db
        .prepare(workspace, draft.revision, actor, Permission::EditSchedules)
        .await?;
    let directory = db.directory(workspace).await?;
    let members = directory.iter().map(|u| u.id).collect();
    let now = Utc::now();
    let mut expanded = generation::expand(
        &record.document,
        workspace,
        &draft.variables,
        &draft.rules,
        draft.route_position,
        &record.document.working_interval,
        &members,
        now,
    );
    let used: std::collections::BTreeSet<_> = expanded
        .document
        .schedules
        .iter()
        .flat_map(|s| match &s.kind {
            ScheduleKind::Rotation { participants, .. }
            | ScheduleKind::Priority { participants, .. } => participants.clone(),
        })
        .chain(expanded.document.escalations.iter().flat_map(|e| {
            e.steps.iter().filter_map(|s| match s.recipient {
                Recipient::User { id } => Some(id),
                _ => None,
            })
        }))
        .collect();
    for user in &directory {
        if used.contains(&user.id) && expanded.document.person(user.id).is_none() {
            expanded.document.people.push(Person {
                id: user.id,
                user_id: Some(user.id),
                display_name: user.display_name.clone(),
                email: None,
                country: Some(user.country.clone()),
                aliases: vec![],
            });
        }
    }
    if expanded.issues.is_empty() {
        if let Err(e) = expanded.document.validate(&members) {
            expanded.issues.push(Issue {
                path: "People".into(),
                message: e.to_string(),
                ..Issue::default()
            });
        }
        if let Err(e) = providers::validate_capabilities(&expanded.document, now) {
            expanded.issues.push(Issue {
                path: "Provider".into(),
                message: e.to_string(),
                ..Issue::default()
            });
        }
        // Both shared and manually configured calendars must remain valid under DST.
        if let Err(e) = engine::timeline(
            &expanded.document,
            now,
            now + Duration::days(i64::from(expanded.document.horizon_days)),
        ) {
            expanded.issues.push(Issue {
                path: "Calendar".into(),
                message: e.to_string(),
                ..Issue::default()
            });
        }
    }

    let issues = expanded.issues;
    let cancelled = record
        .document
        .requests
        .iter()
        .filter(|r| {
            r.status == RequestStatus::Pending
                && expanded
                    .document
                    .requests
                    .iter()
                    .any(|n| n.id == r.id && n.status == RequestStatus::Cancelled)
        })
        .count();
    let result=issues.is_empty().then(||{let d=&expanded.document;json!({"timezone":d.timezone,"people":d.people,"schedules":d.schedules,"escalations":d.escalations,"routes":d.routes,"managed":d.generation.managed})});
    let review = generation::stable_id(&json!([
        workspace,
        draft.revision,
        draft.variables,
        draft.rules,
        draft.route_position
    ]))
    .to_string();
    let report = json!({"review_id":review,"changes":expanded.changes,"cancelled_requests":cancelled,"result":result,"trace":expanded.trace,"issues":issues});
    record.document = expanded.document;
    Ok(Prepared {
        report,
        record,
        issues,
        review,
    })
}
pub async fn preview(db: &Store, actor: Uuid, workspace: Uuid, draft: Draft) -> Result<Value> {
    Ok(prepare(db, actor, workspace, &draft).await?.report)
}
pub async fn apply(db: &Store, actor: Uuid, workspace: Uuid, draft: Draft) -> Result<Value> {
    let mut prepared = prepare(db, actor, workspace, &draft).await?;
    ensure(
        prepared.issues.is_empty(),
        prepared
            .issues
            .iter()
            .take(8)
            .map(|i| format!("{}: {}", i.path, i.message))
            .collect::<Vec<_>>()
            .join("; "),
    )?;
    ensure(
        draft.review_id.as_deref() == Some(prepared.review.as_str()),
        crate::i18n::text("err_the_preview_is_stale_check_the_updated_impact_be_85cacd"),
    )?;
    db.commit(
        &mut prepared.record,
        actor,
        Permission::EditSchedules,
        "generation.applied",
        prepared.report,
        None,
    )
    .await?;
    Ok(json!({"ok":true}))
}