//! Seeds — so as not to start from a blank page.
//!
//! On start, missing groups are created and every `seeds/*.json` document is
//! instantiated in each group it names, **only if that group does not hold it
//! yet**. An existing document is never touched: from its first vote on, it
//! is runtime data.

use crate::AppState;
use crate::util::{self, LangMap};
use serde::Deserialize;
use std::path::Path;

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct SeedDoc {
    pub slug: String,
    pub title: LangMap,
    pub summary: LangMap,
    pub source_lang: String,
    pub instances: Vec<SeedInstance>,
    pub units: Vec<SeedUnit>,
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct SeedInstance {
    pub group: String,
    pub vote_floor: f64,
    pub publish_path: Option<String>,
}

#[derive(Deserialize)]
pub struct SeedUnit {
    pub code: String,
    pub section: Option<String>,
    pub position: f64,
    pub inertia: String,
    pub versions: Vec<SeedVersion>,
}

#[derive(Deserialize)]
pub struct SeedVersion {
    pub label: Option<String>,
    /// `in_force` (seed a minima) or `open` (proposal at zero votes).
    pub status: String,
    pub title: LangMap,
    pub body: LangMap,
}

pub async fn ensure_groups(state: &AppState) -> anyhow::Result<()> {
    for (position, g) in trustin_access::default_groups().into_iter().enumerate() {
        sqlx::query(
            "INSERT OR IGNORE INTO groups (slug, name, parent, policy, hidden, position) VALUES (?, ?, ?, ?, ?, ?)",
        )
        .bind(&g.slug)
        .bind(&g.name)
        .bind(&g.parent)
        .bind(g.policy.as_str())
        .bind(g.hidden)
        .bind(i64::try_from(position).unwrap_or(0))
        .execute(&state.db)
        .await?;
    }
    Ok(())
}

pub async fn ensure(state: &AppState) -> anyhow::Result<()> {
    ensure_groups(state).await?;
    let dir = state.cfg.seed_dir.clone();
    let mut entries = match tokio::fs::read_dir(&dir).await {
        Ok(e) => e,
        Err(e) => {
            tracing::warn!(dir = %dir.display(), error = %e, "no seed directory");
            return Ok(());
        }
    };
    let mut files = Vec::new();
    while let Some(entry) = entries.next_entry().await? {
        let path = entry.path();
        if path.extension().is_some_and(|x| x == "json") {
            files.push(path);
        }
    }
    files.sort();
    for path in files {
        load_file(state, &path).await?;
    }
    Ok(())
}

async fn load_file(state: &AppState, path: &Path) -> anyhow::Result<()> {
    let raw = tokio::fs::read_to_string(path).await?;
    let seed: SeedDoc = serde_json::from_str(&raw).map_err(|e| anyhow::anyhow!("{}: {e}", path.display()))?;
    for inst in &seed.instances {
        let group_exists: i64 = sqlx::query_scalar("SELECT COUNT(*) FROM groups WHERE slug = ?")
            .bind(&inst.group)
            .fetch_one(&state.db)
            .await?;
        if group_exists == 0 {
            tracing::warn!(group = %inst.group, slug = %seed.slug, "seed names an unknown group");
            continue;
        }
        let present: i64 = sqlx::query_scalar("SELECT COUNT(*) FROM documents WHERE group_slug = ? AND slug = ?")
            .bind(&inst.group)
            .bind(&seed.slug)
            .fetch_one(&state.db)
            .await?;
        if present > 0 {
            continue;
        }
        instantiate(state, &seed, inst).await?;
        tracing::info!(group = %inst.group, slug = %seed.slug, "seed instantiated");
    }
    Ok(())
}

async fn instantiate(state: &AppState, seed: &SeedDoc, inst: &SeedInstance) -> anyhow::Result<()> {
    let src = seed.source_lang.as_str();
    let pick = |m: &LangMap| m.get(src).cloned().unwrap_or_default();
    let now = util::now();
    let doc_id = util::id();
    let mut tx = state.db.begin().await?;
    sqlx::query(
        "INSERT INTO documents (id, group_slug, slug, title, summary, source_lang, vote_floor, publish_path, created_at)
         VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)",
    )
    .bind(&doc_id)
    .bind(&inst.group)
    .bind(&seed.slug)
    .bind(util::lang_json(&seed.title))
    .bind(util::lang_json(&seed.summary))
    .bind(src)
    .bind(inst.vote_floor)
    .bind(&inst.publish_path)
    .bind(&now)
    .execute(&mut *tx)
    .await?;
    for unit in &seed.units {
        let unit_id = util::id();
        sqlx::query(
            "INSERT INTO units (id, doc_id, code, section, position, inertia, in_force_id, created_at)
             VALUES (?, ?, ?, ?, ?, ?, NULL, ?)",
        )
        .bind(&unit_id)
        .bind(&doc_id)
        .bind(&unit.code)
        .bind(&unit.section)
        .bind(unit.position)
        .bind(&unit.inertia)
        .bind(&now)
        .execute(&mut *tx)
        .await?;
        for v in &unit.versions {
            let pid = util::id();
            let (title, body) = (pick(&v.title), pick(&v.body));
            let status = if v.status == "in_force" { "in_force" } else { "open" };
            sqlx::query(
                "INSERT INTO proposals (id, unit_id, kind, title, body, status, origin, label, author_id, revision,
                   created_at, updated_at, submitted_at)
                 VALUES (?, ?, 'text', ?, ?, ?, 'seed', ?, NULL, 1, ?, ?, ?)",
            )
            .bind(&pid)
            .bind(&unit_id)
            .bind(&title)
            .bind(&body)
            .bind(status)
            .bind(&v.label)
            .bind(&now)
            .bind(&now)
            .bind(&now)
            .execute(&mut *tx)
            .await?;
            sqlx::query(
                "INSERT INTO revisions (proposal_id, revision, kind, title, body, author_id, created_at) VALUES (?, 1, 'initial', ?, ?, NULL, ?)",
            )
            .bind(&pid)
            .bind(&title)
            .bind(&body)
            .bind(&now)
            .execute(&mut *tx)
            .await?;
            if status == "in_force" {
                sqlx::query("UPDATE units SET in_force_id = ? WHERE id = ?")
                    .bind(&pid)
                    .bind(&unit_id)
                    .execute(&mut *tx)
                    .await?;
            }
            let hash = util::source_hash(&title, &body);
            for lang in util::LANGS.iter().filter(|l| **l != src) {
                let (Some(t), Some(b)) = (v.title.get(*lang), v.body.get(*lang)) else { continue };
                sqlx::query(
                    "INSERT INTO translations (proposal_id, lang, title, body, source_hash, origin, updated_by, updated_at)
                     VALUES (?, ?, ?, ?, ?, 'seed', NULL, ?)",
                )
                .bind(&pid)
                .bind(lang)
                .bind(t)
                .bind(b)
                .bind(&hash)
                .bind(&now)
                .execute(&mut *tx)
                .await?;
            }
        }
    }
    if inst.publish_path.is_some() {
        sqlx::query(
            "INSERT INTO outbox (doc_id, reason, created_at, next_at) VALUES (?, 'publication initiale', ?, ?)",
        )
        .bind(&doc_id)
        .bind(&now)
        .bind(&now)
        .execute(&mut *tx)
        .await?;
    }
    tx.commit().await?;
    Ok(())
}