WITH
  "tabletable" as ( SELECT "table".oid,
           "table".relkind,
           "table".relname AS "table_name",
           "schema".nspname AS "table_schema"
      FROM pg_catalog.pg_class "table"
      JOIN pg_catalog.pg_namespace "schema"
          ON schema.oid = "table".relnamespace
      WHERE "table".relkind IN ('r', 't', 'v', 'm', 'f', 'p')
        -- and tables not from any system schemas
        AND "schema".nspname NOT LIKE 'pg_%'
        AND "schema".nspname NOT IN ('information_schema', 'hdb_catalog', 'hdb_lib', '_timescaledb_internal', 'crdb_internal')
  )
SELECT
  "table".table_schema,
  "table".table_name,

  -- This field corresponds to the `DBTableMetadata` Haskell type
  jsonb_build_object(
    'oid', "table".oid :: integer,
    'columns', coalesce(columns.info, '[]'),
    'primary_key', primary_key.info,
    -- Note: unique_constraints does NOT include primary key constraints!
    'unique_constraints', coalesce(unique_constraints.info, '[]'),
    'foreign_keys', coalesce(foreign_key_constraints.info, '[]'),
    -- Note: for views and materialized views, we are asking Postgres if it is mutable or not
    --       and for any other case, we are assuming it to be mutable.
    'view_info', CASE WHEN "table".relkind IN ('v', 'm') THEN jsonb_build_object(
      'is_updatable', ((pg_catalog.pg_relation_is_updatable("table".oid, true) & 4) = 4),
      'is_insertable', ((pg_catalog.pg_relation_is_updatable("table".oid, true) & 8) = 8),
      'is_deletable', ((pg_catalog.pg_relation_is_updatable("table".oid, true) & 16) = 16)
    ) END,
    'description', description.description,
    'extra_table_metadata', '[]'::json
  )::json AS info
FROM "tabletable" "table"

-- tracked tables
-- $1 parameter provides JSON array of tracked tables
-- FROM
--   ( SELECT "tracked"."name" AS "table_name",
--            "tracked"."schema" AS "table_schema"
--       FROM jsonb_to_recordset($1::jsonb) AS "tracked"("schema" text, "name" text)
--   ) "tracked_table"

-- table & schema
-- LEFT JOIN
--  ( SELECT "table".oid,
--           "table".relkind,
--           "table".relname AS "table_name",
--           "schema".nspname AS "table_schema"
--      FROM pg_catalog.pg_class "table"
--      JOIN pg_catalog.pg_namespace "schema"
--          ON schema.oid = "table".relnamespace
--  ) "table"
  --ON  "table"."table_name" = "tracked_table"."table_name"
  --AND "table"."table_schema" = "tracked_table"."table_schema"

-- description
LEFT JOIN pg_catalog.pg_description description
  ON  description.classoid = 'pg_catalog.pg_class'::regclass
  AND description.objoid = "table".oid
  AND description.objsubid = 0

-- columns
LEFT JOIN LATERAL
  ( SELECT jsonb_agg(jsonb_build_object(
      'name', "column".attname,
      'position', "column".attnum,
      'type', json_build_object('name', coalesce(base_type.typname, "type".typname), 'type', "type".typtype),
      'is_nullable', NOT "column".attnotnull,
      'description', '', -- pg_catalog.col_description("table".oid, "column".attnum), -- removing this for now as it takes ~20 seconds per lookup
      'mutability', jsonb_build_object(
        'is_insertable', NOT ("column".attidentity = 'a' OR "column".attgenerated = 's'),
        'is_updatable', NOT ("column".attidentity = 'a' OR "column".attgenerated = 's'))
    )) AS info
    FROM pg_catalog.pg_attribute "column"

    LEFT JOIN pg_catalog.pg_type "type"
      ON "type".oid = "column".atttypid
    LEFT JOIN pg_catalog.pg_type base_type
      ON "type".typtype = 'd' AND base_type.oid = "type".typbasetype
    WHERE "column".attrelid = "table".oid
      -- columns where attnum <= 0 are special, system-defined columns
      AND "column".attnum > 0
      -- dropped columns still exist in the system catalog as "zombie" columns, so ignore those
      AND NOT "column".attisdropped
  ) columns ON true

-- primary key
LEFT JOIN LATERAL
  ( SELECT jsonb_build_object(
      'constraint', jsonb_build_object(
        'name', class.relname,
        'oid', class.oid :: integer),
      'columns', coalesce(columns.info, '[]')
    ) AS info
    FROM pg_catalog.pg_index idx
    JOIN pg_catalog.pg_class class
      ON class.oid = idx.indexrelid
    LEFT JOIN LATERAL
      ( SELECT jsonb_agg("column".attname) AS info
        FROM pg_catalog.pg_attribute "column"
        WHERE "column".attrelid = "table".oid
          AND "column".attnum = ANY (idx.indkey)
      ) AS columns ON true
    WHERE idx.indrelid = "table".oid
      AND idx.indisprimary
  ) primary_key ON true

-- unique constraints
LEFT JOIN LATERAL
  ( SELECT jsonb_agg(
      jsonb_build_object(
        'constraint', jsonb_build_object(
          'name', class.relname,
          'oid', class.oid :: integer
          ),
        'columns', coalesce(columns.info, '[]')
        )
      ) AS info
    FROM pg_catalog.pg_index idx
    JOIN pg_catalog.pg_class class
      ON class.oid = idx.indexrelid
    LEFT JOIN LATERAL
      ( SELECT jsonb_agg("column".attname) AS info
        FROM pg_catalog.pg_attribute "column"
        WHERE "column".attrelid = "table".oid
          AND "column".attnum = ANY (idx.indkey)
      ) AS columns ON true
    WHERE idx.indrelid = "table".oid
      AND idx.indisunique
      AND NOT idx.indisprimary
  ) unique_constraints ON true

-- foreign keys
LEFT JOIN
  ( SELECT jsonb_agg(jsonb_build_object(
      'constraint', jsonb_build_object(
        'name', foreign_key.constraint_name,
        'oid', foreign_key.constraint_oid :: integer
      ),
      'columns', foreign_key.columns,
      'foreign_table', jsonb_build_object(
        'schema', foreign_key.ref_table_table_schema,
        'name', foreign_key.ref_table
      ),
      'foreign_columns', foreign_key.ref_columns
    )) AS info, -- This field corresponds to the `PGForeignKeyMetadata` Haskell type
    foreign_key.table_schema,
    foreign_key.table_name
    FROM (SELECT
             q.table_schema :: text,
             q.table_name :: text,
             q.constraint_name :: text,
             min(q.constraint_oid) :: integer as constraint_oid,
             min(q.ref_table_table_schema) :: text as ref_table_table_schema,
             min(q.ref_table) :: text as ref_table,
             json_agg(ac.attname) as columns,
             json_agg(afc.attname) as ref_columns
         FROM
             (SELECT
                 ctn.nspname AS table_schema,
                 ct.relname AS table_name,
                 r.conrelid AS table_id,
                 r.conname as constraint_name,
                 r.oid as constraint_oid,
                 cftn.nspname AS ref_table_table_schema,
                 cft.relname as ref_table,
                 r.confrelid as ref_table_id,
                 UNNEST (r.conkey) AS column_id,
                 UNNEST (r.confkey) AS ref_column_id
              FROM
                  pg_catalog.pg_constraint r
                  JOIN pg_catalog.pg_class ct
                    ON r.conrelid = ct.oid
                  JOIN pg_catalog.pg_namespace ctn
                    ON ct.relnamespace = ctn.oid
                  JOIN pg_catalog.pg_class cft
                    ON r.confrelid = cft.oid
                  JOIN pg_catalog.pg_namespace cftn
                    ON cft.relnamespace = cftn.oid
              WHERE
                  r.contype = 'f'
             ) q
             JOIN pg_catalog.pg_attribute ac
               ON q.column_id = ac.attnum
                  AND q.table_id = ac.attrelid
             JOIN pg_catalog.pg_attribute afc
               ON q.ref_column_id = afc.attnum
                  AND q.ref_table_id = afc.attrelid
         GROUP BY q.table_schema, q.table_name, q.constraint_name
    ) foreign_key
    GROUP BY foreign_key.table_schema, foreign_key.table_name
  ) foreign_key_constraints
    ON "table".table_name = foreign_key_constraints.table_name
       AND "table".table_schema = foreign_key_constraints.table_schema;

-- -- all these identify table-like things
-- WHERE "table".relkind IN ('r', 't', 'v', 'm', 'f', 'p')
--   -- and tables not from any system schemas
--   AND "table".table_schema NOT LIKE 'pg_%'
--   AND "table".table_schema NOT IN ('information_schema', 'hdb_catalog', 'hdb_lib', '_timescaledb_internal', 'crdb_internal');