/*
 * Copyright (c) 2021 Huawei Device Co., Ltd.
 *
 * HDF is dual licensed: you can use it either under the terms of
 * the GPL, or the BSD license, at your option.
 * See the LICENSE file in the root of this repository for complete details.
 */

#include "parser/lexer.h"
#include "util/string_builder.h"

namespace OHOS {
namespace HDI {
Lexer::Lexer()
{
    InitializeKeywords();
}

Lexer::~Lexer()
{
    if (currentFile_ != nullptr) {
        currentFile_->Close();
    }
}

void Lexer::InitializeKeywords()
{
    keywords_ = {
        { "boolean", Token::BOOLEAN }, { "byte", Token::BYTE }, { "callback", Token::CALLBACK },
        { "char", Token::CHAR}, { "double", Token::DOUBLE }, { "enum", Token::ENUM },
        { "extends", Token::EXTENDS }, { "float", Token::FLOAT }, { "full", Token::FULL },
        { "import", Token::IMPORT }, { "in", Token::IN }, { "int", Token::INTEGER }, { "interface", Token::INTERFACE },
        { "List", Token::LIST }, { "lite", Token::LITE }, { "long", Token::LONG },
        { "Map", Token::MAP }, { "oneway", Token::ONEWAY }, { "out", Token::OUT },
        { "package", Token::PACKAGE}, { "sequenceable", Token::SEQUENCEABLE }, { "short", Token::SHORT },
        { "String", Token::STRING }, { "struct", Token::STRUCT }, { "union", Token::UNION },
        { "unsigned", Token::UNSIGNED }, { "FileDescriptor", Token::FILEDESCRIPTOR },
        {"SharedMemQueue", Token::SMEMQUEUE},
    };

    delimiters_ = {
        {'<', Token::ANGLE_BRACKETS_LEFT}, {'>', Token::ANGLE_BRACKETS_RIGHT},
        {'{', Token::BRACES_LEFT}, {'}', Token::BRACES_RIGHT},
        {'[', Token::BRACKETS_LEFT}, {']', Token::BRACKETS_RIGHT},
        {',', Token::COMMA}, {'(', Token::PARENTHESES_LEFT},
        {')', Token::PARENTHESES_RIGHT}, {'.', Token::DOT},
        {':', Token::COLON}, {';', Token::SEMICOLON},
        {'=', Token::ASSIGN}
    };

    tokenDumps_ = {
        { Token::ANGLE_BRACKETS_LEFT, "<" }, { Token::ANGLE_BRACKETS_RIGHT, ">"}, { Token::BOOLEAN, "boolean"},
        { Token::BRACES_LEFT, "{"}, { Token::BRACES_RIGHT, "}"}, { Token::BRACKETS_LEFT, "["},
        { Token::BRACKETS_RIGHT, "]"}, { Token::BYTE, "byte"}, { Token::CALLBACK, "callback"},
        { Token::CHAR, "char"}, { Token::COLON, ":"}, { Token::COMMA, ","},
        { Token::DOT, "."}, { Token::DOUBLE, "double"}, { Token::END_OF_FILE, "eof"},
        { Token::ENUM, "enum"}, { Token::EXTENDS, "extends"}, { Token::FLOAT, "float"},
        { Token::FULL, "full"}, { Token::IMPORT, "import"}, { Token::IN, "in"},
        { Token::INTEGER, "int"}, { Token::INTERFACE, "interface"}, { Token::LITE, "lite"},
        { Token::LIST, "List"}, { Token::LONG, "long"}, { Token::MAP, "Map"},
        { Token::ONEWAY, "oneway"}, { Token::OUT, "out"}, { Token::PACKAGE, "package"},
        { Token::SEQUENCEABLE, "sequenceable"}, { Token::STRUCT, "struct"}, { Token::PARENTHESES_LEFT, "("},
        { Token::PARENTHESES_RIGHT, ")"}, { Token::SEMICOLON, ";"}, { Token::SHORT, "short"},
        { Token::STRING, "String"}, { Token::UNION, "union"}, { Token::UNSIGNED, "unsigned"},
        { Token::FILEDESCRIPTOR, "FileDescriptor"}, {Token::SMEMQUEUE, "SharedMemQueue"},
    };
}

bool Lexer::OpenSourceFile(const String& filePath)
{
    currentFile_ = std::make_unique<File>(filePath, int(File::READ));
    if (!currentFile_->IsValid()) {
        return false;
    }

    return true;
}

Token Lexer::GetToken(bool skipComment)
{
    if (!havePeek_) {
        currentToken_ = ReadToken(skipComment);
    }
    havePeek_ = false;
    return currentToken_;
}

Token Lexer::PeekToken(bool skipComment)
{
    if (!havePeek_) {
        currentToken_ = ReadToken(skipComment);
        havePeek_ = true;
    }
    return currentToken_;
}

Token Lexer::ReadToken(bool skipComment)
{
    while (!currentFile_->IsEof()) {
        char c = currentFile_->GetChar();
        tokenLineNo_ = currentFile_->GetCharLineNumber();
        tokenColumnNo_ = currentFile_->GetCharColumnNumber();
        if (IsSpace(c)) {
            continue;
        } else if (IsAlphabet(c) || c == '_') {
            Token t = ReadIdentifier(c);
            return t;
        } else if (IsDecimalDigital(c)) {
            Token t = ReadDecimalDigital(c);
            return t;
        }

        auto iter = delimiters_.find(c);
        if (iter != delimiters_.end()) {
            return iter->second;
        }

        if (c == '/') {
            if (currentFile_->PeekChar() == '/') {
                ReadLineComment(c);
            } else if (currentFile_->PeekChar() == '*') {
                ReadBlockComment(c);
            } else {
                currentToken_ = Token::UNKNOWN;
                return currentToken_;
            }

            if (skipComment) {
                continue;
            }

            return currentToken_;
        }

        currentToken_ = Token::UNKNOWN;
        return currentToken_;
    }
    currentToken_ = Token::END_OF_FILE;
    return currentToken_;
}

Token Lexer::ReadIdentifier(char c)
{
    StringBuilder sb;

    sb.Append(c);
    while (!currentFile_->IsEof()) {
        c = currentFile_->PeekChar();
        if (IsAlphabet(c) || c == '_' || IsDecimalDigital(c) || c == '.') {
            c = currentFile_->GetChar();
            sb.Append(c);
            continue;
        }
        if (IsSpace(c)) {
            currentFile_->GetChar();
        }
        break;
    }
    String key = sb.ToString();
    auto it = keywords_.find(key);
    if (it == keywords_.end()) {
        identifier_ = key;
        currentToken_ = Token::IDENTIFIER;
    } else {
        currentToken_ = it->second;
    }

    return currentToken_;
}

Token Lexer::ReadDecimalDigital(char c)
{
    StringBuilder sb;
    sb.Append(c);
    while (!currentFile_->IsEof()) {
        c = currentFile_->PeekChar();
        if (IsDecimalDigital(c)) {
            c = currentFile_->GetChar();
            sb.Append(c);
            continue;
        } else {
            break;
        }
    }
    digit_ = sb.ToString();
    currentToken_ = Token::DIGIT;
    return currentToken_;
}

Token Lexer::ReadLineComment(char c)
{
    StringBuilder sb;

    sb.Append(c);
    while (!currentFile_->IsEof()) {
        c = currentFile_->GetChar();
        if (c == '\n') {
            break;
        }
        sb.Append(c);
    }
    comment_ = sb.ToString();
    currentToken_ = Token::COMMENT_LINE;
    return currentToken_;
}

Token Lexer::ReadBlockComment(char c)
{
    StringBuilder sb;

    sb.Append(c);
    while (!currentFile_->IsEof()) {
        c = currentFile_->GetChar();
        sb.Append(c);
        if (c == '*' && currentFile_->PeekChar() == '/') {
            c = currentFile_->GetChar();
            sb.Append(c);
            break;
        }
    }
    comment_ = sb.ToString();
    currentToken_ = Token::COMMENT_BLOCK;
    return currentToken_;
}

void Lexer::SkipCurrentLine()
{
    while (!currentFile_->IsEof()) {
        char c = currentFile_->GetChar();
        if (c == '\n') {
            currentFile_->GetChar();
            return;
        }
    }
}

bool Lexer::SkipCurrentLine(char untilChar)
{
    while (!currentFile_->IsEof()) {
        int c = currentFile_->GetChar();
        if (c == untilChar) {
            return true;
        }
        if (c == '\n') {
            currentFile_->GetChar();
            return false;
        }
    }
    return true;
}

void Lexer::Skip(char untilChar)
{
    while (!currentFile_->IsEof()) {
        int c = currentFile_->GetChar();
        if (c == untilChar) {
            return;
        }
    }
}

void Lexer::SkipEof()
{
    while (!currentFile_->IsEof()) {}
}

int Lexer::TokenToChar(Token token)
{
    switch (token) {
        case Token::ANGLE_BRACKETS_LEFT:
            return '<';
        case Token::ANGLE_BRACKETS_RIGHT:
            return '>';
        case Token::BRACES_LEFT:
            return '{';
        case Token::BRACES_RIGHT:
            return '}';
        case Token::BRACKETS_LEFT:
            return '[';
        case Token::BRACKETS_RIGHT:
            return ']';
        case Token::COMMA:
            return ',';
        case Token::DOT:
            return '.';
        case Token::PARENTHESES_LEFT:
            return '(';
        case Token::PARENTHESES_RIGHT:
            return ')';
        case Token::COLON:
            return ':';
        case Token::SEMICOLON:
            return ';';
        default:
            return -1;
    }
}

String Lexer::DumpToken() const
{
    auto iter = tokenDumps_.find(currentToken_);
    if (iter != tokenDumps_.end()) {
        return iter->second;
    }

    if (currentToken_ == Token::COMMENT_BLOCK || currentToken_ == Token::COMMENT_LINE) {
        return comment_;
    }

    if (currentToken_ == Token::IDENTIFIER) {
        return identifier_;
    }

    return "unknown token";
}
} // namespace HDI
} // namespace OHOS