# code-gen for data decl languages

from engine.ast import ColRef, TableInfo, ast_node, Context, include
from engine.scan import scan
from engine.utils import base62uuid

class create_table(ast_node):
    name = 'create_table'
    def __init__(self, parent: "ast_node", node, context: Context = None, cexpr = None):
        self.cexpr = cexpr
        super().__init__(parent, node, context)
    def produce(self, node):
        if type(node) is not TableInfo:
            ct = node[self.name]
            tbl = self.context.add_table(ct['name'], ct['columns'])
        else:
            tbl = node
            
        col_type_str = ','.join([c.type for c in tbl.columns])
        # create tables in c
        self.emit(f"auto {tbl.table_name} = new TableInfo<{col_type_str}>(\"{tbl.table_name}\", {tbl.n_cols});")
        self.emit("cxt->tables.insert({\"" + tbl.table_name + f"\", {tbl.table_name}"+"});")
        self.context.tables_in_context[tbl] = tbl.table_name
        tbl.cxt_name = tbl.table_name
        tbl.refer_all()
        if self.cexpr is None:
            for c in tbl.columns:
                self.emit(f"{c.cxt_name}.init();")
        else:
            if len(self.context.scans) == 0:
                for i, c in enumerate(tbl.columns):
                    self.emit(f"{c.cxt_name}.init();")
                    self.emit(f"{c.cxt_name} = {self.cexpr[i]()};")
            else:
                scanner:scan = self.context.scans[-1]
                for i, c in enumerate(tbl.columns):
                    scanner.add(f"{c.cxt_name}.init();", "init")
                    scanner.add(f"{c.cxt_name} = {self.cexpr[i](scanner.it_ver)};")

class insert(ast_node):
    name = 'insert'
    def produce(self, node):
        ct = node[self.name]
        table:TableInfo = self.context.tables_byname[ct]

        values = node['query']['select']
        if len(values) != table.n_cols:
            raise ValueError("Column Mismatch")
        table.refer_all()
        for i, s in enumerate(values):
            if 'value' in s:
                cname = table.columns[i].cxt_name
                self.emit(f"{cname}.emplace_back({s['value']});")
            else:
                # subquery, dispatch to select astnode
                pass
            
class c(ast_node):
    name='c'
    def produce(self, node):
        self.emit(node[self.name])
        
class load(ast_node):
    name="load"
    def produce(self, node):
        self.context.headers.add('"csv.h"')
        node = node[self.name]
        table:TableInfo = self.context.tables_byname[node['table']]
        table.refer_all()
        csv_reader_name = 'csv_reader_' + base62uuid(6)
        col_types = [c.type for c in table.columns]
        col_tmp_names = ['tmp_'+base62uuid(8) for _ in range(len(table.columns))]
        # col_type_str = ",".join(col_types)
        col_names = ','.join([f'"{c.name}"' for c in table.columns])
        
        self.emit(f'io::CSVReader<{len(col_types)}> {csv_reader_name}("{node["file"]["literal"]}");')
        self.emit(f'{csv_reader_name}.read_header(io::ignore_extra_column, {col_names});')
        for t, n in zip(col_types, col_tmp_names):
            self.emit(f'{t} {n};')
        self.emit(f'while({csv_reader_name}.read_row({",".join(col_tmp_names)})) {{ \n')
        for i, c in enumerate(table.columns):
            self.emit(f'{c.cxt_name}.emplace_back({col_tmp_names[i]});')
        self.emit('}')
        
            
class outfile(ast_node):
    name="_outfile"
    def produce(self, node):
        out_table:TableInfo = self.parent.out_table
        filename = node['loc']['literal'] if 'loc' in node else node['literal']
        sep = ',' if 'term' not in node else node['term']['literal']
        self.context.headers.add('fstream')
        cout_backup_buffer = 'stdout_' + base62uuid(4)
        ofstream = 'ofstream_' + base62uuid(6)
        
        self.emit(f'auto {cout_backup_buffer} = cout.rdbuf();')
        self.emit(f'auto {ofstream} = ofstream("{filename}");')
        self.emit(f'cout.rdbuf({ofstream}.rdbuf());')
        
        self.emit_no_ln(f"\"{filename}\"1:`csv@(+(")
        l_compound = False
        l_cols = ''
        l_keys = ''
        ending = lambda x: x[:-1] if len(x) > 0 and x[-1]==';' else x
        for i, c in enumerate(out_table.columns):
            c:ColRef
            l_keys += '`' + c.name
            if c.compound:
                if l_compound:
                    l_cols=f'flatBOTH\'+(({ending(l_cols)});{c.cname})'
                else:
                    l_compound = True
                    if i >= 1:
                        l_cols = f'flatRO\'+(({ending(l_cols)});{c.cname})'
                    else:
                        l_cols = c.cname + ';'
            elif l_compound:
                l_cols = f'flatLO\'+(({ending(l_cols)});{c.cname})'
            else:
                l_cols += f"{c.cname};"
        if not l_compound:
            self.emit_no_ln(l_keys + '!(' + ending(l_cols) + ')')
        else:
            self.emit_no_ln(f'{l_keys}!+,/({ending(l_cols)})')
        self.emit('))')
        
        self.emit(f'cout.rdbuf({cout_backup_buffer});')
        self.emit(f'{ofstream}.close();')
        
        
import sys
include(sys.modules[__name__])