James D. B. Nelson

import inspect
from datetime import datetime, timezone
from typing import Any, List, Dict

from elftools.elf.elffile import ELFFile
from elftools.common.exceptions import ELFError

from redb.extractors.enum import Tag
from redb.extractors.elf_extractor import ELFExtractor
from redb.models.dataclasses import ELFRelocation


class ELFRelocationExtractor(ELFExtractor):

    def __init__(
        self,
        filepath,
        log,
        exporters=None,
        index_prefix=None,
        elastic_index=None,
        known_benign=False,
        known_malicious=False,
        elf=None,
    ):
        super().__init__(
            filepath,
            log,
            exporters,
            index_prefix,
            elastic_index,
            known_benign,
            known_malicious,
            elf,
        )
        self.elf_relocations = []
        self.elastic_index = self.index_prefix + "-elf_relocations"
        self.log.debug(inspect.currentframe().f_code.co_name)

    def _get_relocation_type_string(self, reloc_type: int, machine_arch: str) -> str:
        """Convert relocation type number to human-readable string based on architecture."""
        # This is a simplified mapping - real implementation would need comprehensive
        # architecture-specific relocation type mappings

        common_types = {
            0: "R_NONE",
            1: "R_DIRECT",
            2: "R_PC_RELATIVE",
            3: "R_GOT",
            4: "R_PLT",
            5: "R_COPY",
            6: "R_GLOB_DAT",
            7: "R_JMP_SLOT",
            8: "R_RELATIVE"
        }

        # Architecture-specific mappings could be added here
        if machine_arch == "x86_64":
            x86_64_types = {
                1: "R_X86_64_64",
                2: "R_X86_64_PC32",
                3: "R_X86_64_GOT32",
                4: "R_X86_64_PLT32",
                5: "R_X86_64_COPY",
                6: "R_X86_64_GLOB_DAT",
                7: "R_X86_64_JUMP_SLOT",
                8: "R_X86_64_RELATIVE"
            }
            return x86_64_types.get(reloc_type, f"R_X86_64_{reloc_type}")
        elif machine_arch == "x86":
            i386_types = {
                1: "R_386_32",
                2: "R_386_PC32",
                3: "R_386_GOT32",
                4: "R_386_PLT32",
                5: "R_386_COPY",
                6: "R_386_GLOB_DAT",
                7: "R_386_JMP_SLOT",
                8: "R_386_RELATIVE"
            }
            return i386_types.get(reloc_type, f"R_386_{reloc_type}")

        return common_types.get(reloc_type, f"R_UNKNOWN_{reloc_type}")

    def _extract_relocation_data(self, relocation, section_name: str, machine_arch: str) -> Dict:
        """Extract data from a single relocation entry."""
        try:
            # Get relocation offset
            relocation_offset = relocation.entry.get('r_offset', 0)

            # Get relocation type
            relocation_type = relocation.entry.get('r_info_type', 0)

            # Get symbol index
            relocation_symbol_index = relocation.entry.get('r_info_sym', 0)

            # Get addend (only present in RELA sections)
            relocation_addend = None
            if hasattr(relocation.entry, 'r_addend'):
                relocation_addend = relocation.entry.get('r_addend', 0)

            # Get symbol name if available
            relocation_symbol_name = ""
            if hasattr(relocation, 'symbol') and relocation.symbol:
                relocation_symbol_name = relocation.symbol.name or f"<symbol_{relocation_symbol_index}>"
            else:
                relocation_symbol_name = f"<symbol_{relocation_symbol_index}>"

            # Get type string mapping
            relocation_type_str = self._get_relocation_type_string(relocation_type, machine_arch)

            return ELFRelocation(
                relocation_offset=relocation_offset,
                relocation_type=relocation_type,
                relocation_type_str=relocation_type_str,
                relocation_symbol_index=relocation_symbol_index,
                relocation_symbol_name=relocation_symbol_name,
                relocation_section=section_name,
                relocation_addend=relocation_addend
            )

        except Exception as e:
            self.log.error(f"Error extracting relocation data: {e}")
            return None

    def _extract_relocations_from_section(self, section, machine_arch: str) -> List[Dict]:
        """Extract all relocations from a relocation section."""
        relocations = []

        try:
            if not hasattr(section, 'iter_relocations'):
                return relocations

            section_name = section.name or f"<unnamed_section>"

            for relocation in section.iter_relocations():
                reloc_data = self._extract_relocation_data(relocation, section_name, machine_arch)
                if reloc_data:
                    relocations.append(reloc_data)

        except Exception as e:
            self.log.error(f"Error extracting relocations from section {section.name}: {e}")

        return relocations

    def tag(self):
        return Tag.ELF_RELOCATIONS.value if hasattr(Tag, 'ELF_RELOCATIONS') else "elf_relocations"

    def extract(self):
        try:
            self.log.debug(inspect.currentframe().f_code.co_name)

            def extract_data(elf):
                # Get architecture for relocation type mapping
                machine_arch = self._get_architecture()
                all_relocations = []

                # Iterate through all sections looking for relocation sections with per-section error handling
                for section_index, section in enumerate(elf.iter_sections()):
                    try:
                        # Check if this is a relocation section (.rel or .rela)
                        if (section.name and
                            (section.name.startswith('.rel') or section.name.startswith('.rela')) and
                            hasattr(section, 'iter_relocations')):

                            section_relocations = self._extract_relocations_from_section(section, machine_arch)
                            all_relocations.extend(section_relocations)
                            self.log.debug(f"Extracted {len(section_relocations)} relocations from section {section.name}")
                    except Exception as e:
                        section_name = getattr(section, 'name', f'section_{section_index}')
                        self.log.warning(f"Error processing relocation section {section_name}: {e}")
                        # Continue processing other sections

                return all_relocations

            if not self._is_elf_file():
                return None

            result = self._with_elf_file(extract_data)
            if result is None:
                return None

            self.elf_relocations = result
            return self.elf_relocations

        except Exception as e:
            self.log.error(f"Error extracting ELF relocations {self.hash.sha256}: {e}")
            return None

    def prepare_export_data(self, exporter_type: str) -> Any:
        self.log.debug(inspect.currentframe().f_code.co_name)

        if exporter_type == "ElasticsearchExporter":
            return self.elf_relocations
        elif exporter_type == "ClickHouseExporter":
            try:
                # Return valid empty structure if no relocations (e.g., statically linked binary)
                # None is reserved for actual errors

                # Prepare data arrays for all relocations
                data = []
                current_time = datetime.now(timezone.utc)
                for reloc in self.elf_relocations:
                    row = [
                        self.sha256,
                        self.md5,
                        self.sha1,
                        reloc.relocation_offset,
                        reloc.relocation_type,
                        reloc.relocation_type_str,
                        reloc.relocation_symbol_index,
                        reloc.relocation_symbol_name,
                        reloc.relocation_addend,
                        reloc.relocation_section,
                        current_time
                    ]
                    data.append(row)

                column_names = [
                    'sha256', 'md5', 'sha1',
                    'relocation_offset', 'relocation_type', 'relocation_type_str',
                    'relocation_symbol_index', 'relocation_symbol_name',
                    'relocation_addend', 'relocation_section',
                    'analysis_date'
                ]

                if not data:
                    return None

                column_type_names = [
                    'FixedString(64)', 'FixedString(32)', 'FixedString(40)',
                    'UInt64', 'UInt32', 'LowCardinality(String)',
                    'UInt32', 'LowCardinality(String)',
                    'Nullable(Int64)', 'LowCardinality(String)',
                    'DateTime64(3, \'UTC\')'
                ]

                return (data, column_names, column_type_names)

            except Exception as e:
                self.log.error(f"Error preparing export data: {e}")
                raise

    def get_clickhouse_table(self) -> str:
        return "redb_elf_relocations"