import minify from 'pg-minify'

// https://www.postgresql.org/docs/current/catalog-pg-constraint.html

export enum FOREIGN_KEY_DELETION_ACTION {
  NO_ACTION = 'a',
  RESTRICT = 'r',
  CASCADE = 'c',
  SET_NULL = 'n',
  SET_DEFAULT = 'd',
}

export enum CONSTRAINT_TYPE {
  CHECK_CONSTRAINT = 'c',
  FOREIGN_KEY_CONSTRAINT = 'f',
  PRIMARY_KEY_CONSTRAINT = 'p',
  UNIQUE_CONSTRAINT = 'u',
  CONSTRAINT_TRIGGER = 't',
  EXCLUSION_CONSTRAINT = 'x',
}

// Derived from https://github.com/MichaelDBA/pg_get_tabledef

export const CREATE_PG_GET_TABLEDEF_SQL = minify(
  /* SQL */ `
    do $$
    <<first_block>>
    DECLARE
        cnt int;
    BEGIN
      SELECT count(*) into cnt
      FROM pg_catalog.pg_type t LEFT JOIN pg_catalog.pg_namespace n ON n.oid = t.typnamespace WHERE (t.typrelid = 0 OR (SELECT c.relkind = 'c' FROM pg_catalog.pg_class c WHERE c.oid = t.typrelid))
      AND NOT EXISTS(SELECT 1 FROM pg_catalog.pg_type el WHERE el.oid = t.typelem AND el.typarray = t.oid)
      AND n.nspname <> 'pg_catalog' AND n.nspname <> 'information_schema' AND pg_catalog.pg_type_is_visible(t.oid)
      AND pg_catalog.format_type(t.oid, NULL) in ('tabledefs');
      IF cnt = 0 THEN
      CREATE TYPE pg_temp.tabledefs AS ENUM ('FKEYS_INTERNAL', 'FKEYS_EXTERNAL', 'FKEYS_COMMENTED', 'FKEYS_NONE', 'INCLUDE_TRIGGERS', 'NO_TRIGGERS');
      END IF;
    end first_block $$;

    create
    or replace function pg_temp.pg_get_tabledef (
      in_schema varchar,
      in_table varchar,
      _verbose boolean,
      variadic arr pg_temp.tabledefs[] default '{}'::pg_temp.tabledefs[]
    ) returns text language plpgsql volatile as $$
      DECLARE
        v_table_ddl text;
        v_table_oid int;
        v_colrec record;
        v_constraintrec record;
        v_indexrec record;
        v_primary boolean := False;
        v_constraint_name text;
        v_fkey_defs text;
        v_trigger text := '';
        v_partition_key text := '';
        v_partbound text;
        v_parent text;
        v_persist text;
        v_temp  text := '';
        v_relopts text;
        v_tablespace text;
        v_pgversion int;
        bPartition boolean;
        bInheritance boolean;
        bRelispartition boolean;
        constraintarr text[] := '{}';
        constraintelement text;
        bSkip boolean;
      bVerbose boolean := False;

        -- assume defaults for ENUMs at the getgo
      fkcnt            int := 0;
      trigcnt          int := 0;
        fktype           pg_temp.tabledefs := 'FKEYS_INTERNAL';
        trigtype         pg_temp.tabledefs := 'NO_TRIGGERS';
        arglen           integer;
      vargs            text;
      avarg            pg_temp.tabledefs;

        -- exception variables
        v_ret            text;
        v_diag1          text;
        v_diag2          text;
        v_diag3          text;
        v_diag4          text;
        v_diag5          text;
        v_diag6          text;

      BEGIN
        IF _verbose THEN bVerbose = True; END IF;

        arglen := array_length($4, 1);
        IF arglen IS NULL THEN
            -- nothing to do, so assume defaults
            NULL;
        ELSE
            -- loop thru args
            -- IF 'NO_TRIGGERS' = ANY ($4)
            -- select array_to_string($4, ',', '***') INTO vargs;
            IF bVerbose THEN RAISE NOTICE 'arguments=%', $4; END IF;
            FOREACH avarg IN ARRAY $4 LOOP
                IF bVerbose THEN RAISE INFO 'arg=%', avarg; END IF;
                IF avarg = 'FKEYS_INTERNAL' OR avarg = 'FKEYS_EXTERNAL' OR avarg = 'FKEYS_COMMENTED' THEN
                    fkcnt = fkcnt + 1;
                    fktype = avarg;
                ELSEIF avarg = 'INCLUDE_TRIGGERS' OR avarg = 'NO_TRIGGERS' THEN
                    trigcnt = trigcnt + 1;
                    trigtype = avarg;
                END IF;
            END LOOP;
            IF fkcnt > 1 THEN
          RAISE WARNING 'Only one foreign key option can be provided. You provided %', fkcnt;
          RETURN '';
            ELSEIF trigcnt > 1 THEN
                RAISE WARNING 'Only one trigger option can be provided. You provided %', trigcnt;
                RETURN '';
            END IF;
        END IF;

        SELECT c.oid, (select setting from pg_settings where name = 'server_version_num') INTO v_table_oid, v_pgversion FROM pg_catalog.pg_class c LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
        WHERE c.relkind in ('r','p') AND c.relname = in_table AND n.nspname = in_schema;
        IF bVerbose THEN RAISE NOTICE 'version=%', v_pgversion; END IF;

        -- throw an error if table was not found
        IF (v_table_oid IS NULL) THEN
          RAISE EXCEPTION 'table does not exist';
        END IF;

        -- get user-defined tablespaces if applicable
        SELECT tablespace INTO v_temp FROM pg_tables WHERE schemaname = in_schema and tablename = in_table and tablespace IS NOT NULL;
        IF v_temp IS NULL THEN
          v_tablespace := 'TABLESPACE pg_default';
        ELSE
          v_tablespace := 'TABLESPACE ' || v_temp;
        END IF;

        -- also see if there are any SET commands for this table, ie, autovacuum_enabled=off, fillfactor=70
        WITH relopts AS (SELECT unnest(c.reloptions) relopts FROM pg_class c, pg_namespace n WHERE n.nspname = in_schema and n.oid = c.relnamespace and c.relname = in_table)
        SELECT string_agg(r.relopts, ', ') as relopts INTO v_temp from relopts r;
        IF v_temp IS NULL THEN
          v_relopts := '';
        ELSE
          v_relopts := ' WITH (' || v_temp || ')';
        END IF;

        -- -----------------------------------------------------------------------------------
        -- Create table defs for partitions/children using inheritance or declarative methods.
        -- inheritance: pg_class.relkind = 'r'   pg_class.relispartition=false   pg_class.relpartbound is NULL
        -- declarative: pg_class.relkind = 'r'   pg_class.relispartition=true    pg_class.relpartbound is NOT NULL
        -- -----------------------------------------------------------------------------------
        v_partbound := '';
        bPartition := False;
        bInheritance := False;
        IF v_pgversion < 100000 THEN
          SELECT c2.relname parent INTO v_parent from pg_class c1, pg_namespace n, pg_inherits i, pg_class c2
          WHERE n.nspname = in_schema and n.oid = c1.relnamespace and c1.relname = in_table and c1.oid = i.inhrelid and i.inhparent = c2.oid and c1.relkind = 'r';
          IF (v_parent IS NOT NULL) THEN
            bPartition   := True;
            bInheritance := True;
          END IF;
        ELSE
          SELECT c2.relname parent, c1.relispartition, pg_get_expr(c1.relpartbound, c1.oid, true) INTO v_parent, bRelispartition, v_partbound from pg_class c1, pg_namespace n, pg_inherits i, pg_class c2
          WHERE n.nspname = in_schema and n.oid = c1.relnamespace and c1.relname = in_table and c1.oid = i.inhrelid and i.inhparent = c2.oid and c1.relkind = 'r';
          IF (v_parent IS NOT NULL) THEN
            bPartition   := True;
            IF bRelispartition THEN
              bInheritance := False;
            ELSE
              bInheritance := True;
            END IF;
          END IF;
        END IF;

        IF bPartition THEN
          IF bInheritance THEN
            -- inheritance-based
            v_table_ddl := 'CREATE TABLE ' || in_schema || '.' || in_table || '( '|| E'\\n';
            -- Jump to constraints section to add the check constraints
          ELSE
            -- declarative-based
            IF v_relopts <> '' THEN
              v_table_ddl := 'CREATE TABLE ' || in_schema || '.' || in_table || ' PARTITION OF ' || in_schema || '.' || v_parent || ' ' || v_partbound || v_relopts || ' ' || v_tablespace || '; ' || E'\\n';
            ELSE
              v_table_ddl := 'CREATE TABLE ' || in_schema || '.' || in_table || ' PARTITION OF ' || in_schema || '.' || v_parent || ' ' || v_partbound || ' ' || v_tablespace || '; ' || E'\\n';
            END IF;
            -- Jump to constraints and index section to add the check constraints and indexes and perhaps FKeys
          END IF;
        END IF;
      IF bVerbose THEN RAISE INFO '(1)tabledef so far: %', v_table_ddl; END IF;

        IF NOT bPartition THEN
          -- see if this is unlogged or temporary table
          select c.relpersistence into v_persist from pg_class c, pg_namespace n where n.nspname = in_schema and n.oid = c.relnamespace and c.relname = in_table and c.relkind = 'r';
          IF v_persist = 'u' THEN
            v_temp := 'UNLOGGED';
          ELSIF v_persist = 't' THEN
            v_temp := 'TEMPORARY';
          ELSE
            v_temp := '';
          END IF;
        END IF;

        -- start the create definition for regular tables unless we are in progress creating an inheritance-based child table
        IF NOT bPartition THEN
          v_table_ddl := 'CREATE ' || v_temp || ' TABLE ' || in_schema || '.' || in_table || ' (' || E'\\n';
        END IF;
        -- RAISE INFO 'DEBUG2: tabledef so far: %', v_table_ddl;
        -- define all of the columns in the table unless we are in progress creating an inheritance-based child table
        IF NOT bPartition THEN
          FOR v_colrec IN
            SELECT c.column_name, c.data_type, c.udt_name, c.character_maximum_length, c.is_nullable, c.column_default, c.numeric_precision, c.numeric_scale, c.is_identity, c.identity_generation
            FROM information_schema.columns c WHERE (table_schema, table_name) = (in_schema, in_table) ORDER BY ordinal_position
          LOOP
            v_table_ddl := v_table_ddl || '  ' -- note: two char spacer to start, to indent the column
              || v_colrec.column_name || ' '
              -- || CASE WHEN v_colrec.data_type = 'USER-DEFINED' THEN in_schema || '.' || v_colrec.udt_name ELSE v_colrec.data_type END
              || CASE WHEN v_colrec.udt_name in ('geometry', 'box2d', 'box2df', 'box3d', 'geography', 'geometry_dump', 'gidx', 'spheroid', 'valid_detail')
            THEN v_colrec.udt_name WHEN v_colrec.data_type = 'USER-DEFINED' THEN in_schema || '.' || v_colrec.udt_name ELSE v_colrec.data_type END
              || CASE WHEN v_colrec.is_identity = 'YES' THEN CASE WHEN v_colrec.identity_generation = 'ALWAYS' THEN ' GENERATED ALWAYS AS IDENTITY' ELSE ' GENERATED BY DEFAULT AS IDENTITY' END ELSE '' END
              || CASE WHEN v_colrec.character_maximum_length IS NOT NULL THEN ('(' || v_colrec.character_maximum_length || ')')
                      WHEN v_colrec.numeric_precision > 0 AND v_colrec.numeric_scale > 0 THEN '(' || v_colrec.numeric_precision || ',' || v_colrec.numeric_scale || ')'
                ELSE '' END || ' '
              || CASE WHEN v_colrec.is_nullable = 'NO' THEN 'NOT NULL' ELSE 'NULL' END
              || CASE WHEN v_colrec.column_default IS NOT null THEN (' DEFAULT ' || v_colrec.column_default) ELSE '' END
              || ',' || E'\n';
          END LOOP;
        END IF;
        IF bVerbose THEN RAISE INFO '(2)tabledef so far: %', v_table_ddl; END IF;

        -- define all the constraints
        FOR v_constraintrec IN
          SELECT con.conname as constraint_name, con.contype as constraint_type,
            CASE
              WHEN con.contype = 'p' THEN 1 -- primary key constraint
              WHEN con.contype = 'u' THEN 2 -- unique constraint
              WHEN con.contype = 'f' THEN 3 -- foreign key constraint
              WHEN con.contype = 'c' THEN 4
              ELSE 5
            END as type_rank,
            pg_get_constraintdef(con.oid) as constraint_definition
          FROM pg_catalog.pg_constraint con JOIN pg_catalog.pg_class rel ON rel.oid = con.conrelid JOIN pg_catalog.pg_namespace nsp ON nsp.oid = connamespace
          WHERE nsp.nspname = in_schema AND rel.relname = in_table ORDER BY type_rank
        LOOP
          IF v_constraintrec.type_rank = 1 THEN
              v_primary := True;
              v_constraint_name := v_constraintrec.constraint_name;
              IF bPartition THEN
                continue;
              END IF;
          END IF;
          -- RAISE INFO 'DEBUG4: constraint name= %', v_constraintrec.constraint_name;
          constraintarr := constraintarr || v_constraintrec.constraint_name;

          IF fktype <> 'FKEYS_INTERNAL' AND v_constraintrec.constraint_type = 'f' THEN
              continue;
          END IF;

          v_table_ddl := v_table_ddl || '  ' -- note: two char spacer to start, to indent the column
            || 'CONSTRAINT' || ' '
            || v_constraintrec.constraint_name || ' '
            || v_constraintrec.constraint_definition
            || ',' || E'\\n';
        END LOOP;
        IF bVerbose THEN RAISE INFO '(3)tabledef so far: %', v_table_ddl; END IF;

        -- drop the last comma before ending the create statement
        v_table_ddl = substr(v_table_ddl, 0, length(v_table_ddl) - 1) || E'\\n';

        -- ---------------------------------------------------------------------------
        -- at this point we have everything up to the last table-enclosing parenthesis
        -- ---------------------------------------------------------------------------
        IF bVerbose THEN RAISE INFO '(4)tabledef so far: %', v_table_ddl; END IF;

        -- See if this is an inheritance-based child table and finish up the table create.
        IF bPartition and bInheritance THEN
          v_table_ddl := v_table_ddl || ') INHERITS (' || in_schema || '.' || v_parent || ') ' || E'\\n' || v_relopts || ' ' || v_tablespace || ';' || E'\\n';
        END IF;

        IF v_pgversion >= 100000 AND NOT bPartition and NOT bInheritance THEN
          -- See if this is a partitioned table (pg_class.relkind = 'p') and add the partitioned key
          SELECT pg_get_partkeydef(c1.oid) as partition_key INTO v_partition_key FROM pg_class c1 JOIN pg_namespace n ON (n.oid = c1.relnamespace) LEFT JOIN pg_partitioned_table p ON (c1.oid = p.partrelid)
          WHERE n.nspname = in_schema and n.oid = c1.relnamespace and c1.relname = in_table and c1.relkind = 'p';

          IF v_partition_key IS NOT NULL AND v_partition_key <> '' THEN
            -- add partition clause
            -- NOTE:  cannot specify default tablespace for partitioned relations
            -- v_table_ddl := v_table_ddl || ') PARTITION BY ' || v_partition_key || ' ' || v_tablespace || ';' || E'\\n';
            v_table_ddl := v_table_ddl || ') PARTITION BY ' || v_partition_key || ';' || E'\\n';
          ELSEIF v_relopts <> '' THEN
            v_table_ddl := v_table_ddl || ') ' || v_relopts || ' ' || v_tablespace || ';' || E'\\n';
          ELSE
            -- end the create definition
            v_table_ddl := v_table_ddl || ') ' || v_tablespace || ';' || E'\\n';
          END IF;
        END IF;

        IF bVerbose THEN RAISE INFO '(5)tabledef so far: %', v_table_ddl; END IF;

        -- Add closing paren for regular tables
        -- IF NOT bPartition THEN
        -- v_table_ddl := v_table_ddl || ') ' || v_relopts || ' ' || v_tablespace || E';\\n';
        -- END IF;
        -- RAISE NOTICE 'ddlsofar3: %', v_table_ddl;

        -- create indexes
        FOR v_indexrec IN
          SELECT indexdef, COALESCE(tablespace, 'pg_default') as tablespace, indexname FROM pg_indexes WHERE (schemaname, tablename) = (in_schema, in_table)
        LOOP
          -- RAISE INFO 'DEBUG6: indexname=%', v_indexrec.indexname;
          -- loop through constraints and skip ones already defined
          bSkip = False;
          FOREACH constraintelement IN ARRAY constraintarr
          LOOP
            IF constraintelement = v_indexrec.indexname THEN
                -- RAISE INFO 'DEBUG7: skipping index, %', v_indexrec.indexname;
                bSkip = True;
                EXIT;
            END IF;
          END LOOP;
          if bSkip THEN CONTINUE; END IF;

          -- Add IF NOT EXISTS clause so partition index additions will not be created if declarative partition in effect and index already created on parent
          v_indexrec.indexdef := REPLACE(v_indexrec.indexdef, 'CREATE INDEX', 'CREATE INDEX IF NOT EXISTS');
          -- RAISE INFO 'DEBUG8: adding index, %', v_indexrec.indexname;

          -- NOTE:  cannot specify default tablespace for partitioned relations
          IF v_partition_key IS NOT NULL AND v_partition_key <> '' THEN
              v_table_ddl := v_table_ddl || v_indexrec.indexdef || ';' || E'\\n';
          ELSE
              v_table_ddl := v_table_ddl || v_indexrec.indexdef || ' TABLESPACE ' || v_indexrec.tablespace || ';' || E'\\n';
          END IF;

        END LOOP;
        IF bVerbose THEN RAISE INFO '(6)tabledef so far: %', v_table_ddl; END IF;

        -- Handle external foreign key defs here if applicable.
        IF fktype = 'FKEYS_EXTERNAL' THEN
          SELECT 'ALTER TABLE ONLY ' || n.nspname || '.' || c2.relname || ' ADD CONSTRAINT ' || r.conname || ' ' || pg_catalog.pg_get_constraintdef(r.oid, true) || ';' into v_fkey_defs
          FROM pg_constraint r, pg_class c1, pg_namespace n, pg_class c2 where r.conrelid = c1.oid and  r.contype = 'f' and n.nspname = in_schema and n.oid = r.connamespace and r.conrelid = c2.oid and c2.relname = in_table;
        IF v_fkey_defs IS NOT NULL THEN
              v_table_ddl := v_table_ddl || v_fkey_defs;
        END IF;
        ELSIF  fktype = 'FKEYS_COMMENTED' THEN
          SELECT '-- ALTER TABLE ONLY ' || n.nspname || '.' || c2.relname || ' ADD CONSTRAINT ' || r.conname || ' ' || pg_catalog.pg_get_constraintdef(r.oid, true) || ';' into v_fkey_defs
          FROM pg_constraint r, pg_class c1, pg_namespace n, pg_class c2 where r.conrelid = c1.oid and  r.contype = 'f' and n.nspname = in_schema and n.oid = r.connamespace and r.conrelid = c2.oid and c2.relname = in_table;
        IF v_fkey_defs IS NOT NULL THEN
              v_table_ddl := v_table_ddl || v_fkey_defs;
          END IF;
        END IF;
        IF bVerbose THEN RAISE INFO '(7)tabledef so far: %', v_table_ddl; END IF;

        IF trigtype = 'INCLUDE_TRIGGERS' THEN
          select pg_get_triggerdef(t.oid, True) || ';' INTO v_trigger FROM pg_trigger t, pg_class c, pg_namespace n
          WHERE n.nspname = in_schema and n.oid = c.relnamespace and c.relname = in_table and c.relkind = 'r' and t.tgrelid = c.oid and NOT t.tgisinternal;
          IF v_trigger <> '' THEN
            v_table_ddl := v_table_ddl || v_trigger;
          END IF;
        END IF;

        -- add empty line
        v_table_ddl := v_table_ddl || E'\\n';

        RETURN v_table_ddl;

        EXCEPTION
        WHEN others THEN
        BEGIN
          GET STACKED DIAGNOSTICS v_diag1 = MESSAGE_TEXT, v_diag2 = PG_EXCEPTION_DETAIL, v_diag3 = PG_EXCEPTION_HINT, v_diag4 = RETURNED_SQLSTATE, v_diag5 = PG_CONTEXT, v_diag6 = PG_EXCEPTION_CONTEXT;
          -- v_ret := 'line=' || v_diag6 || '. '|| v_diag4 || '. ' || v_diag1 || ' .' || v_diag2 || ' .' || v_diag3;
          v_ret := 'line=' || v_diag6 || '. '|| v_diag4 || '. ' || v_diag1;
          RAISE EXCEPTION '%', v_ret;
          -- put additional coding here if necessarY
          RETURN '';
        END;

      END;
    $$;`,
  { compress: true, removeAll: true }
)