//! Team templates — canonical rosters + tool bundles that materialize
//! concrete `teams` rows. Slice 3 of the missions consolidation.
//!
//! Rows with `source = 'builtin'` are re-upserted from disk (TOML
//! recipes under `templates/teams/`) at server boot. `source = 'user'`
//! rows are workspace-authored and never overwritten by the loader.

use serde::{Deserialize, Serialize};
use serde_json::Value;
use sqlx::PgPool;
use time::OffsetDateTime;
use uuid::Uuid;

use crate::DbError;

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct TeamTemplate {
    pub id: Uuid,
    pub key: String,
    pub name: String,
    pub stack: Vec<String>,
    pub default_topology: String,
    pub risk_profile: String,
    pub mcp_bundles: Vec<String>,
    pub version: i32,
    pub description: Option<String>,
    pub config: Value,
    pub source: String,
    pub workspace_id: Option<Uuid>,
    /// 'research' | 'development' | 'security' | 'ops'
    #[serde(default = "default_category")]
    pub category: String,
    #[serde(with = "time::serde::rfc3339")]
    pub created_at: OffsetDateTime,
    #[serde(with = "time::serde::rfc3339")]
    pub updated_at: OffsetDateTime,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct TemplateRole {
    pub template_id: Uuid,
    pub slot: String,
    pub order_idx: i32,
    pub system_prompt: String,
    pub skills: Vec<String>,
    pub brain_seed: Option<String>,
    /// Which model this role's claw runs on. `None` takes the mint's default —
    /// which is what every role did unconditionally before migration 0071, and
    /// why a template could not put its reviewer on a different model from the
    /// coder it reviews.
    #[serde(default)]
    pub model: Option<String>,
}

#[derive(Debug, Clone, Serialize)]
pub struct TeamTemplateDetail {
    #[serde(flatten)]
    pub template: TeamTemplate,
    pub roles: Vec<TemplateRole>,
}

#[derive(Debug, Clone)]
pub struct UpsertBuiltinRole<'a> {
    pub slot: &'a str,
    pub order_idx: i32,
    pub system_prompt: &'a str,
    pub skills: Vec<String>,
    pub brain_seed: Option<&'a str>,
    /// Optional per-role model. `None` leaves the mint's default in place.
    pub model: Option<&'a str>,
}

#[derive(Debug, Clone)]
pub struct UpsertBuiltin<'a> {
    /// Caller-provided deterministic id (typically a hash of `key`
    /// computed in cm-api's loader — cm-db doesn't need the hashing
    /// dep just for this one thing).
    pub id: Uuid,
    pub key: &'a str,
    pub name: &'a str,
    pub stack: Vec<String>,
    pub default_topology: &'a str,
    pub risk_profile: &'a str,
    pub mcp_bundles: Vec<String>,
    pub version: i32,
    pub description: Option<&'a str>,
    pub config: Value,
    /// 'research' | 'development' | 'security' | 'ops'. Defaults to
    /// 'development' at the loader level so old TOML files without a
    /// category still upsert as coding teams.
    pub category: &'a str,
    pub roles: Vec<UpsertBuiltinRole<'a>>,
}

fn default_category() -> String {
    "development".to_string()
}

/// Upsert a builtin template + its roles in one txn. Idempotent.
pub async fn upsert_builtin(pool: &PgPool, b: UpsertBuiltin<'_>) -> Result<Uuid, DbError> {
    let id = b.id;
    let mut tx = pool.begin().await?;

    sqlx::query(
        "INSERT INTO team_templates
           (id, key, name, stack, default_topology, risk_profile,
            mcp_bundles, version, description, config, source, workspace_id, category)
         VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,'builtin',NULL,$11)
         ON CONFLICT (id) DO UPDATE SET
             key              = EXCLUDED.key,
             name             = EXCLUDED.name,
             stack            = EXCLUDED.stack,
             default_topology = EXCLUDED.default_topology,
             risk_profile     = EXCLUDED.risk_profile,
             mcp_bundles      = EXCLUDED.mcp_bundles,
             version          = EXCLUDED.version,
             description      = EXCLUDED.description,
             config           = EXCLUDED.config,
             category         = EXCLUDED.category,
             updated_at       = now()",
    )
    .bind(id)
    .bind(b.key)
    .bind(b.name)
    .bind(&b.stack)
    .bind(b.default_topology)
    .bind(b.risk_profile)
    .bind(&b.mcp_bundles)
    .bind(b.version)
    .bind(b.description)
    .bind(&b.config)
    .bind(b.category)
    .execute(&mut *tx)
    .await?;

    // Upsert each role in place, then prune only the slots the TOML dropped.
    //
    // This was `DELETE FROM template_roles` + reinsert, which looks equivalent
    // and is not: `agent_template_link` carries a plain FK on
    // (template_id, role_slot), so once a template has minted a single agent
    // the delete is rejected and the whole upsert transaction rolls back. The
    // effect was that **a template stopped accepting edits the moment it was
    // first used** — the loader logged a foreign-key error and moved on, so
    // the on-disk TOML and the DB drifted apart silently, and only for the
    // templates anyone actually ran.
    for r in &b.roles {
        sqlx::query(
            "INSERT INTO template_roles
               (template_id, slot, order_idx, system_prompt, skills, brain_seed, model)
             VALUES ($1,$2,$3,$4,$5,$6,$7)
             ON CONFLICT (template_id, slot) DO UPDATE SET
                 order_idx     = EXCLUDED.order_idx,
                 system_prompt = EXCLUDED.system_prompt,
                 skills        = EXCLUDED.skills,
                 brain_seed    = EXCLUDED.brain_seed,
                 model         = EXCLUDED.model",
        )
        .bind(id)
        .bind(r.slot)
        .bind(r.order_idx)
        .bind(r.system_prompt)
        .bind(&r.skills)
        .bind(r.brain_seed)
        .bind(r.model)
        .execute(&mut *tx)
        .await?;
    }

    // Prune removed slots, but never at the cost of the whole upsert: a slot
    // still referenced by a live agent is left in place and reported. Losing
    // one stale role row is a smaller failure than losing every edit to the
    // template.
    let slots: Vec<String> = b.roles.iter().map(|r| r.slot.to_string()).collect();
    let stale: Vec<String> = sqlx::query_scalar(
        "SELECT slot FROM template_roles
          WHERE template_id = $1 AND slot <> ALL($2)",
    )
    .bind(id)
    .bind(&slots)
    .fetch_all(&mut *tx)
    .await?;
    for slot in stale {
        let referenced: i64 = sqlx::query_scalar(
            "SELECT count(*) FROM agent_template_link
              WHERE template_id = $1 AND role_slot = $2",
        )
        .bind(id)
        .bind(&slot)
        .fetch_one(&mut *tx)
        .await?;
        if referenced > 0 {
            eprintln!(
                "team_templates: role {}.{slot} was removed from the TOML but {referenced} \
                 agent(s) still reference it — keeping the row so the upsert can commit",
                b.key
            );
            continue;
        }
        sqlx::query("DELETE FROM template_roles WHERE template_id = $1 AND slot = $2")
            .bind(id)
            .bind(&slot)
            .execute(&mut *tx)
            .await?;
    }

    tx.commit().await?;
    Ok(id)
}

pub async fn list_all(pool: &PgPool) -> Result<Vec<TeamTemplate>, DbError> {
    let rows = sqlx::query(
        "SELECT id, key, name, stack, default_topology, risk_profile,
                mcp_bundles, version, description, config, source,
                workspace_id, category, created_at, updated_at
         FROM team_templates
         WHERE source = 'builtin' OR workspace_id IS NOT NULL
         ORDER BY source DESC, name ASC",
    )
    .fetch_all(pool)
    .await?;
    Ok(rows.into_iter().map(row_to_template).collect())
}

pub async fn get(pool: &PgPool, id: Uuid) -> Result<Option<TeamTemplateDetail>, DbError> {
    use sqlx::Row;
    let Some(t) = sqlx::query(
        "SELECT id, key, name, stack, default_topology, risk_profile,
                mcp_bundles, version, description, config, source,
                workspace_id, category, created_at, updated_at
         FROM team_templates WHERE id = $1",
    )
    .bind(id)
    .fetch_optional(pool)
    .await?
    .map(row_to_template) else {
        return Ok(None);
    };
    let role_rows = sqlx::query(
        "SELECT template_id, slot, order_idx, system_prompt, skills, brain_seed, model
         FROM template_roles WHERE template_id = $1
         ORDER BY order_idx ASC",
    )
    .bind(id)
    .fetch_all(pool)
    .await?;
    let roles = role_rows
        .into_iter()
        .map(|r| TemplateRole {
            template_id: r.get("template_id"),
            slot: r.get("slot"),
            order_idx: r.get("order_idx"),
            system_prompt: r.get("system_prompt"),
            skills: r.get("skills"),
            brain_seed: r.get("brain_seed"),
            model: r.get("model"),
        })
        .collect();
    Ok(Some(TeamTemplateDetail { template: t, roles }))
}

pub async fn get_by_key(pool: &PgPool, key: &str) -> Result<Option<TeamTemplate>, DbError> {
    let row = sqlx::query(
        "SELECT id, key, name, stack, default_topology, risk_profile,
                mcp_bundles, version, description, config, source,
                workspace_id, category, created_at, updated_at
         FROM team_templates WHERE key = $1",
    )
    .bind(key)
    .fetch_optional(pool)
    .await?;
    Ok(row.map(row_to_template))
}

fn row_to_template(r: sqlx::postgres::PgRow) -> TeamTemplate {
    use sqlx::Row;
    TeamTemplate {
        id: r.get("id"),
        key: r.get("key"),
        name: r.get("name"),
        stack: r.get("stack"),
        default_topology: r.get("default_topology"),
        risk_profile: r.get("risk_profile"),
        mcp_bundles: r.get("mcp_bundles"),
        version: r.get("version"),
        description: r.get("description"),
        config: r.get("config"),
        source: r.get("source"),
        workspace_id: r.get("workspace_id"),
        category: r
            .try_get("category")
            .unwrap_or_else(|_| "development".to_string()),
        created_at: r.get("created_at"),
        updated_at: r.get("updated_at"),
    }
}