#include <stdlib.h>

#include "typeutils.h"
#include "lex.h"

DECLARE_VEC(char*, StrVec)


typedef struct {
    Token* ptr;
    size_t len;
    size_t pos;
} TokStream;

typedef enum {
    STDIN_REDIR,
    STDOUT_REDIR_TRUNC,
    STDOUT_REDIR_APPEND,
} RedirKind;


typedef struct {
    RedirKind kind;

    union {
        Word std_redir_filename;
    } as;
} Redirect;
DECLARE_VEC(Redirect, RedirectVec)


typedef struct {
    WordVec args;
    RedirectVec redirects;
    // TODO: prefix variable settings
} Command;


typedef enum {
    CONN_PIPE,
    CONN_EOL,
    // TODO: add the |& thingy
} Connector;


typedef struct {
    Command cmd;
    Connector conn;
} PipelineElement;


DECLARE_VEC(PipelineElement, Pipeline)



Command parse_command(TokStream* toks) {
    WordVec args = make_WordVec(256);
    RedirectVec redirects = make_RedirectVec(256);
    for (
        Token curr_tok; 
        (curr_tok = toks->ptr[toks->pos], !(curr_tok.kind == TOK_SPECIAL && (curr_tok.as.spec == PIPE && curr_tok.as.spec == EOL)));
        toks->pos++
    ) {
        if (curr_tok.kind == TOK_SPECIAL) {
            Token tok;
            switch (curr_tok.as.spec) {
                case WRITE_REDIR_TRUNC:
                    toks->pos++;
                    tok = toks->ptr[toks->pos];
                    if(tok.kind != TOK_WORD) exit(1);
                    push_to_RedirectVec(&redirects, (Redirect){.kind = STDOUT_REDIR_TRUNC, .as.std_redir_filename = tok.as.word});
                    break;
                case WRITE_REDIR_APPEND:
                    toks->pos++;
                    tok = toks->ptr[toks->pos];
                    if(tok.kind != TOK_WORD) exit(1);
                    push_to_RedirectVec(&redirects, (Redirect){.kind = STDOUT_REDIR_APPEND, .as.std_redir_filename = tok.as.word});
                    break;
                case READ_REDIR:
                    toks->pos++;
                    tok = toks->ptr[toks->pos];
                    if(tok.kind != TOK_WORD) exit(1);
                    push_to_RedirectVec(&redirects, (Redirect){.kind = STDOUT_REDIR_APPEND, .as.std_redir_filename = tok.as.word});
                    break;
                default:
                    exit(69);
            } 
        } else  if (curr_tok.kind == TOK_WORD){
            push_to_WordVec(&args, curr_tok.as.word);
        } 
    }
    return (Command){.args = args, .redirects = redirects};
}


Pipeline parse_tokstream(TokenVec toks) {
    TokStream tokstream = {.ptr = toks.items, .len = toks.count, .pos = 0};
    Pipeline result = make_Pipeline(256);
}