#include "parser.h"
#include "SolsNode.h"

#include "../include/estr.h"
#include "../include/ansii.h"

ResultType(SolsParser, charptr) createSolsParser(SolsTokens* input) {
    ResultType(SolsNode, charptr) node = createSolsNode(SNT_ROOT);
    if (node.error) {
        Estr str = CREATE_ESTR(node.as.error);
        APPEND_ESTR(str, " (in createSolsParser() function)");
    }
    SolsParser parser = {
        .input = input,
        .current = 0,
        .output = node.as.success,
        .errors.capacity = 32,
        .errors.count = 0,
        .errors.at = malloc(sizeof(char*) * 32)
    };
    if (parser.errors.at == NULL) {
        return Error(SolsParser, charptr, "Couldn't allocate memory to store errors (in createSolsParser() function)");
    }
    parser.currentParent = &parser.output;
    return Success(SolsParser, charptr, parser);
}

void createParserError(SolsParser* parser, char* what) {

    ResultType(SolsToken, Nothing) prevToken;
    SolsToken token = parserPeek(parser, 0).as.success;
    ResultType(SolsToken, Nothing) nextToken;

    // Find tokens for previous line and next line
    for (size_t i = parser->current; i > 0; i--) {
        prevToken = parserLookAt(parser, i);
        if (prevToken.error || prevToken.as.success.line.num != token.line.num) {
            break;
        }
    }
    if (prevToken.error || prevToken.as.success.line.num == token.line.num) {
        prevToken = Error(SolsToken, Nothing, {});
    }

    for (size_t i = parser->current; i <= parser->input->count; i++) {
        nextToken = parserLookAt(parser, i);
        if (nextToken.error || nextToken.as.success.line.num != token.line.num) {
            break;
        }
    }
    if (nextToken.error || nextToken.as.success.line.num == token.line.num) {
        nextToken = Error(SolsToken, Nothing, {});
    }

    if (parser->errors.count + 1 >= parser->errors.capacity) {
        parser->errors.capacity *= 2;
        char** tmp = realloc(parser->errors.at, sizeof(char*) * parser->errors.capacity);
        if (tmp == NULL) {
            parser->errors.at[parser->errors.count - 1] = "Failed to allocate more memory for createParserError function";
            return;
        }
    }
    Estr err = CREATE_ESTR(ESC_BOLD ESC_RED_FG "error: " ESC_RESET ESC_BOLD);
    
    // Append the main error message and a newline
    APPEND_ESTR(err, what);
    APPEND_ESTR(err, "\n" ESC_RESET);

    APPEND_ESTR(err, ESC_CYAN_FG "-> " ESC_RESET);
    APPEND_ESTR(err, "on line ");
    
    // Format the line number
    char line_buf[16];
    snprintf(line_buf, sizeof(line_buf), "%zu", token.line.num);
    APPEND_ESTR(err, line_buf);

    APPEND_ESTR(err, "\n\n");
    // Append line before
    if (!prevToken.error) {
        APPEND_ESTR(err, prevToken.as.success.line.content);
        APPEND_ESTR(err, "\n");
    }
    // Append the actual content of the line that failed
    APPEND_ESTR(err, token.line.content);
    APPEND_ESTR(err, "\n");
    if (!nextToken.error) {
        APPEND_ESTR(err, nextToken.as.success.line.content);
        APPEND_ESTR(err, "\n");
    }

    // Output the final constructed error
    parser->errors.at[parser->errors.count] = err.str;
    parser->errors.count++;
}

static inline ResultType(Nothing, charptr) parseIdentifier(SolsParser* parser) {
    ResultType(SolsToken, Nothing) peek = parserPeek(parser, 0);
    return Error(Nothing, charptr, "Not an error, just curious what errors look like");
    
    return Success(Nothing, charptr, {});
}
static inline ResultType(Nothing, charptr) parseLiteral(SolsParser* parser) {
    return Error(Nothing, charptr, "Not an error, just curious what errors look like");

    return Success(Nothing, charptr, {});
}

static inline ResultType(Nothing, charptr) parsePuts(SolsParser* parser) {
    return Error(Nothing, charptr, "Not an error, just curious what errors look like");
    return Success(Nothing, charptr, {});
}

ResultType(Nothing, charptr) parse(SolsParser* parser) {
    for (;;) {
        ResultType(SolsToken, Nothing) token = parserConsume(parser);
        if (token.error) {
            break;
        }
        switch (token.as.success.type) {
            case STT_IDENTIFIER: PARSER_HANDLE(Identifier);
            case STT_LITERAL: PARSER_HANDLE(Literal);
            case STT_KW_PUTS: PARSER_HANDLE(Puts);
        }
    }
    if (parser->errors.count > 0) {
        Estr estr = CREATE_ESTR("");
        for (size_t i = 0; i < parser->errors.count; i++) {
            APPEND_ESTR(estr, parser->errors.at[i]);
            APPEND_ESTR(estr, "\n");
        }
        return Error(Nothing, charptr, estr.str);
    }
    return Success(Nothing, charptr, {});
}

ResultType(SolsToken, Nothing) parserLookAt(SolsParser* parser, size_t where) {
    if (parser->input == NULL) {
        return Error(SolsToken, Nothing, {});
    }
    if (where >= parser->input->count) {
        return Error(SolsToken, Nothing, {});
    }
    return Success(SolsToken, Nothing, parser->input->at[where]);
}

ResultType(SolsToken, Nothing) parserPeek(SolsParser* parser, size_t ahead) {
    if (parser->input == NULL) {
        return Error(SolsToken, Nothing, {});
    }
    if (parser->current + ahead - 1 >= parser->input->count) {
        return Error(SolsToken, Nothing, {});
    } 
    return Success(SolsToken, Nothing, parser->input->at[parser->current + ahead - 1]);
}

ResultType(SolsToken, Nothing) parserConsume(SolsParser* parser) {
    if (parser->input == NULL) {
        return Error(SolsToken, Nothing, {});
    }
    if (parser->current + 1 >= parser->input->count) {
        return Error(SolsToken, Nothing, {});
    } 
    return Success(SolsToken, Nothing, parser->input->at[parser->current ++]);
}