#include <stdio.h>
#include <string.h>

#include "node.h"

#define STRING_BUFF_SIZE 1024

static char stringBuff[STRING_BUFF_SIZE];

Node* parseHeader(Token** firstToken);
Node* parseCodeBlock(Token** firstToken);

Node*
ParseNodes(Token* firstToken)
{
    Node* firstNode = NULL;

    Token* currentToken = firstToken;
    Node* prevNode = NULL;

    while (1) {
        Node* currentNode = NULL;

        switch (currentToken->type) {
            case TT_NEWLINE:
                break;
            case TT_HASH:
                // start of header
                currentNode = parseHeader(&currentToken);
                break;

            case TT_TRIPLEBACKTICK:
                currentNode = parseCodeBlock(&currentToken);
                break;

            case TT_EOF:
                return firstNode;

            default:    // paragraph start?
                break;
        }

        if (currentToken->next == NULL) {
            printf("currentToken->next == NULL\n");
            break;
        }

        currentToken = currentToken->next;
        if (currentNode == NULL)
            continue;

        if (prevNode != NULL) {
            prevNode->next = currentNode;
        }

        if (firstNode == NULL) {
            firstNode = currentNode;
        }

        prevNode = currentNode;
    }

    return firstNode;
}

Node*
parseHeader(Token** startToken)
{
    Token* t = *startToken;
    // Count the number of TT_HASH tokens
    int count = 1;
    while (t->next != NULL && t->next->type == TT_HASH)
    {
        count++;
        t = t->next;
    }

    if (t->next == NULL)
    {
        printf("Header missing text");
        return NULL;
    }
    t = t->next;

    // Trim leading whitespace
    while (t->next != NULL && t->type == TT_WHITESPACE)
    {
        t = t->next;
    }

    if (t->next == NULL)
    {
        printf("Header missing text");
        return NULL;
    }

    Token* end = t;
    int len = 0;
    // find header text size
    while (end->type != TT_NEWLINE && end->type != TT_EOF) {
        len += end->length;
        end = end->next;
    }

    char* strbuff = malloc(len+1);
    strbuff[0] = '\0';

    while(t != end) {
        strncat(strbuff, t->literal, t->length);
        t = t->next;
    }


    *startToken = t;

    HeaderNode* retval = malloc(sizeof(HeaderNode));
    switch(count) {
        case 1:
            retval->type = NT_Header1;
            break;
        case 2:
            retval->type = NT_Header2;
            break;
        case 3:
            retval->type = NT_Header3;
            break;
        default:
            retval->type = NT_Header4;
            break;
    }

    retval->next = NULL;
    retval->rawText = strbuff;

    return (Node*)retval;
}

Node*
parseCodeBlock(Token** startToken)
{
    // find closing ticks
    int tlen = 0;   // number of tokens
    int clen = 0;   // number of characters
    Token* t = *startToken;
    t = t->next; // skip past the opening triple backtick

    // skip the first newline
    if (t->type == TT_NEWLINE) {
        t = t->next;
    }

    while (t->next != NULL && t->type != TT_TRIPLEBACKTICK) {
        if (t->next->type == TT_EOF) {
            printf("premature EOF");

            ErrorNode* err = malloc(sizeof(ErrorNode));
            err->type = NT_Error;
            err->next = NULL;
            err->error = "premature EOF searching for closing triple backtick";

            return (Node*)err;
        }

        tlen++;
        clen += t->length;
        t = t->next;
    }

    t = *startToken;

    char* strbuff = malloc(sizeof(char)*clen+1);
    strbuff[0] = '\0';
    int i;
    t = t->next; // skip past the opening triple backtick

    // skip the first newline
    if (t->type == TT_NEWLINE) {
        t = t->next;
    }

    for(i = 0; i < tlen; i++) {
        strncat(strbuff, t->literal, t->length);
        t = t->next;
    }

    // skip past closing triple backtick
    *startToken = t->next;

    CodeBlockNode* ret = malloc(sizeof(CodeBlockNode));
    ret->type = NT_BlockCode;
    ret->rawText = strbuff;
    ret->next = NULL;
    return (Node*)ret;
}

char*
NodeTypeString(NodeType t)
{
    switch(t) {
        case NT_Header1:
            return "NT_Header1";
        case NT_Header2:
            return "NT_Header2";
        case NT_Header3:
            return "NT_Header3";
        case NT_Header4:
            return "NT_Header4";
        case NT_Paragraph:
            return "NT_Paragraph";
        case NT_UnorderedList:
            return "NT_UnorderedList";
        case NT_OrderedList:
            return "NT_OrderedList";
        case NT_InlineCode:
            return "NT_InlineCode";
        case NT_BlockCode:
            return "NT_BlockCode";
        case NT_BlockQuote:
            return "NT_BlockQuote";
        case NT_Bold:
            return "NT_Bold";
        case NT_Underline:
            return "NT_Underline";
        case NT_Error:
            return "NT_Error";

        default:
            snprintf(stringBuff, 1000, "unknown NodeType: %d", t);
            return stringBuff;
    }
}