/**
 * /ai-infrastructure — AI / HPC index. Counts use ai_evidence confirmed | likely (or the legacy is_ai flag);
 * "associated" facilities are reported separately and never counted as AI infrastructure.
 */
import type { AiIndex } from "@dci/core";
import { pg, facilityJoins, facilitySummaryCols, facilityView, knownMwAgg, pipelineMwAgg, countedAgg, hasMwAgg, mwExpr, projectJoins, projectSummaryCols, projectLive, CONSTRUCTION_SET, type Sql } from "../lib/sql.js";
import { int, num, reqStr, type Row } from "../lib/rows.js";
import { asStatus, facilitySummary, projectSummary, round2, share } from "../lib/dto.js";
import { eventsWhere } from "./events.js";

export const AI_EVIDENCE_NOTE = "AI evidence levels: confirmed = a source explicitly describes the site as AI / HPC / GPU / accelerated-computing infrastructure; likely = AI-ready, high-density, liquid- or direct-to-chip cooling or GPU signals in the source; associated = only an AI tenant, customer or company mention (reported separately, NOT counted as AI infrastructure); unknown = no signal. A single keyword never confirms a site. Counts and MW cover confirmed + likely only; MW figures are published site-scoped figures (containment-aware), never extrapolated.";

const AI_F = (sql: Sql) => sql`(f.ai_evidence in ('confirmed', 'likely') or f.is_ai or f.facility_type = 'ai')`;
const AI_P = (sql: Sql) => sql`(p.ai_evidence in ('confirmed', 'likely') or p.is_ai)`;

export async function aiIndex(): Promise<AiIndex> {
  const sql = pg();
  const known = knownMwAgg(sql), pipe = pipelineMwAgg(sql), counted = countedAgg(sql), hasMw = hasMwAgg(sql);
  const [fs, ps, topOps, topMetros, topCountries, stages, recentProjects, facilities, recentAnnouncements] = await Promise.all([
    sql<Row[]>`select count(*) filter (where ${counted} and ${AI_F(sql)})::int as facilities,
        count(*) filter (where ${counted} and f.ai_evidence = 'confirmed')::int as confirmed,
        count(*) filter (where ${counted} and f.ai_evidence = 'likely')::int as likely,
        count(*) filter (where ${counted} and f.ai_evidence = 'associated')::int as associated,
        sum(${pipe}) filter (where ${AI_F(sql)} and f.status = any(${CONSTRUCTION_SET}))::float as construction_mw,
        sum(${known}) filter (where ${AI_F(sql)} and f.status in ('operational', 'partially_operational', 'expansion'))::float as known_mw,
        count(*) filter (where ${counted} and ${AI_F(sql)} and ${hasMw})::int as with_mw,
        count(distinct f.country_iso2) filter (where ${AI_F(sql)})::int as f_countries,
        count(distinct f.operator_id) filter (where ${AI_F(sql)})::int as f_operators
      from ${facilityView(sql)} f`,
    sql<Row[]>`select count(*)::int as projects, sum(p.planned_mw)::float as planned_mw, count(distinct p.country_iso2)::int as countries, count(distinct p.operator_id)::int as operators from projects p where ${projectLive(sql)} and ${AI_P(sql)}`,
    sql<Row[]>`select * from (select o.id, o.slug, o.name,
        (select count(*) from ${facilityView(sql)} f where f.operator_id = o.id and ${counted} and ${AI_F(sql)})::int as facilities,
        (select count(*) from projects p where p.operator_id = o.id and ${projectLive(sql)} and ${AI_P(sql)})::int as projects,
        (select sum(p.planned_mw) from projects p where p.operator_id = o.id and ${projectLive(sql)} and ${AI_P(sql)})::float as planned_mw
      from operators o where exists (select 1 from facilities f where f.operator_id = o.id and f.merged_into is null and ${AI_F(sql)}) or exists (select 1 from projects p where p.operator_id = o.id and ${projectLive(sql)} and ${AI_P(sql)})) t order by t.facilities + t.projects desc, t.planned_mw desc nulls last, t.name limit 10`,
    sql<Row[]>`select * from (select m.id, m.slug, m.name, m.country_iso2,
        (select count(*) from ${facilityView(sql)} f where f.metro_id = m.id and ${counted} and ${AI_F(sql)})::int as facilities,
        (select count(*) from projects p where p.metro_id = m.id and ${projectLive(sql)} and ${AI_P(sql)})::int as projects,
        (select sum(p.planned_mw) from projects p where p.metro_id = m.id and ${projectLive(sql)} and ${AI_P(sql)})::float as planned_mw
      from metros m where exists (select 1 from facilities f where f.metro_id = m.id and f.merged_into is null and ${AI_F(sql)}) or exists (select 1 from projects p where p.metro_id = m.id and ${projectLive(sql)} and ${AI_P(sql)})) t order by t.facilities + t.projects desc, t.planned_mw desc nulls last, t.name limit 10`,
    sql<Row[]>`select * from (select c.iso2, c.slug, c.name,
        (select count(*) from ${facilityView(sql)} f where f.country_iso2 = c.iso2 and ${counted} and ${AI_F(sql)})::int as facilities,
        (select count(*) from projects p where p.country_iso2 = c.iso2 and ${projectLive(sql)} and ${AI_P(sql)})::int as projects,
        (select sum(p.planned_mw) from projects p where p.country_iso2 = c.iso2 and ${projectLive(sql)} and ${AI_P(sql)})::float as planned_mw
      from countries c where exists (select 1 from facilities f where f.country_iso2 = c.iso2 and f.merged_into is null and ${AI_F(sql)}) or exists (select 1 from projects p where p.country_iso2 = c.iso2 and ${projectLive(sql)} and ${AI_P(sql)})) t order by t.facilities + t.projects desc, t.planned_mw desc nulls last, t.name limit 10`,
    sql<Row[]>`select p.status, count(*)::int as n, sum(p.planned_mw)::float as mw from projects p where ${projectLive(sql)} and ${AI_P(sql)} group by 1 order by n desc`,
    sql<Row[]>`select ${projectSummaryCols(sql)} from projects p ${projectJoins(sql)} where ${projectLive(sql)} and ${AI_P(sql)} order by p.last_update desc limit 10`,
    sql<Row[]>`select ${facilitySummaryCols(sql)} from facilities f ${facilityJoins(sql)} where f.merged_into is null and ${AI_F(sql)} order by ${mwExpr(sql)} desc nulls last, f.completeness desc limit 30`,
    eventsWhere(sql`e.is_ai = true`, 15),
  ]);
  const f = fs[0] ?? {};
  const p = ps[0] ?? {};
  const facilitiesN = int(f.facilities);
  return {
    stats: {
      facilities: facilitiesN,
      confirmed: int(f.confirmed),
      likely: int(f.likely),
      associated: int(f.associated),
      projects: int(p.projects),
      plannedMw: round2(num(p.planned_mw)),
      constructionMw: round2(num(f.construction_mw)),
      countries: Math.max(int(f.f_countries), int(p.countries)),
      operators: Math.max(int(f.f_operators), int(p.operators)),
      mwCoverage: share(int(f.with_mw), facilitiesN),
    },
    topOperators: topOps.map((r) => ({ id: reqStr(r.id), slug: reqStr(r.slug), name: reqStr(r.name), facilities: int(r.facilities), projects: int(r.projects), plannedMw: round2(num(r.planned_mw)) })),
    topMetros: topMetros.map((r) => ({ id: reqStr(r.id), slug: reqStr(r.slug), name: reqStr(r.name), countryIso2: reqStr(r.country_iso2), facilities: int(r.facilities), projects: int(r.projects), plannedMw: round2(num(r.planned_mw)) })),
    topCountries: topCountries.map((r) => ({ iso2: reqStr(r.iso2), slug: reqStr(r.slug), name: reqStr(r.name), facilities: int(r.facilities), projects: int(r.projects), plannedMw: round2(num(r.planned_mw)) })),
    pipelineByStage: stages.map((r) => ({ status: asStatus(r.status), count: int(r.n), mw: round2(num(r.mw)) })),
    recentAnnouncements,
    recentProjects: recentProjects.map(projectSummary),
    facilities: facilities.map(facilitySummary),
    evidenceNote: AI_EVIDENCE_NOTE,
  };
}