# Progress Log
## 2025-11-23
### Project Initialization
- Created Rust project structure with `cargo new base-d`
- Set up initial documentation:
- README.md with project overview and usage examples
- ROADMAP.md with planned features across 5 phases
- PROGRESS.md for tracking development
### Design Decisions
- **Primary Alphabet**: Starting with Unicode playing cards (52 characters)
- Suits: Spades (🂡-🂮), Hearts (🂱-🂾), Diamonds (🃁-🃎), Clubs (🃑-🃞)
- 13 ranks per suit = 52 total characters (excluding knights 🂬🂼🃌🃜)
- **Dual Purpose**: Library crate + CLI binary
- **API Design**: Similar to base58/base64 patterns for familiarity
### Phase 1: Core Functionality - COMPLETED ✓
#### Implemented
- ✅ Alphabet struct with encode/decode methods
- Character-to-index mapping via HashMap
- Validation for duplicate characters
- **NEW**: `from_str()` method for easy alphabet creation
- ✅ **TOML-based configuration system**
- `alphabets.toml` for defining alphabets
- `AlphabetsConfig` for loading and accessing alphabets
- Embedded TOML file via `include_str!` for default config
- Easy to add new alphabets without code changes
- ✅ Playing Cards alphabet (52 Unicode characters)
- Removed knights to get exactly 52 cards
- Now defined in `alphabets.toml`
- ✅ Base encoding/decoding algorithm
- Uses `num-bigint` for arbitrary precision
- Handles leading zeros correctly
- Proper roundtrip for all test cases
- ✅ Library API
- `encode(data: &[u8], alphabet: &Alphabet) -> String`
- `decode(encoded: &str, alphabet: &Alphabet) -> Result<Vec<u8>, DecodeError>`
- `Alphabet::from_str(s: &str)` for creating alphabets
- `AlphabetsConfig::load_default()` for loading built-in alphabets
- ✅ Comprehensive unit tests (10 tests, all passing)
- Empty data
- Single zero byte
- Simple strings
- Binary data
- Leading zeros
- Invalid characters
- Config loading and validation
#### Example Output
```
"Hello, World!" encodes to: 🃎🃅🃝🃉🂡🂣🂸🃉🃉🃇🃉🃓🂵🂣🂨🂻🃆🃍
```
### Architecture Improvements
- **Configuration-driven**: Alphabets are now data, not code
- **Extensible**: Add new alphabets by editing TOML file
- **Type-safe**: Serde for TOML parsing with validation
- **Zero-cost abstraction**: Alphabet parsing happens once at load time
### Next Steps
1. ~~Begin Phase 2: CLI Tool implementation~~ ✓ COMPLETED
2. ~~Add `clap` for command-line parsing~~ ✓
3. ~~Implement `encode` and `decode` subcommands~~ ✓
4. ~~Add input/output options (stdin, files, strings)~~ ✓
5. ~~Add encoding mode support (mathematical vs chunked)~~ ✓ COMPLETED
6. ~~Phase 3: Add common encoding alphabets~~ ✓ COMPLETED
7. ~~Phase 4: Add esoteric Unicode alphabets~~ ✓ COMPLETED
### Phase 4: Esoteric Alphabets - COMPLETED ✓
#### Implemented (32 total alphabets!)
**Ancient Scripts (3):**
- ✅ hieroglyphs (Egyptian, 100 chars)
- ✅ cuneiform (Sumerian, 100 chars)
- ✅ runic (Elder Futhark, 81 chars)
**Game Pieces (4):**
- ✅ domino (100 tiles)
- ✅ mahjong (44 tiles)
- ✅ chess (12 pieces)
- ✅ cards (52 playing cards)
**Esoteric Symbols (5):**
- ✅ alchemy (116 alchemical symbols)
- ✅ zodiac (12 zodiac signs)
- ✅ weather (72 weather & misc symbols)
- ✅ music (100 musical notation symbols)
- ✅ arrows (112 arrow symbols)
**Emoji (2):**
- ✅ emoji_faces (80 face emoji)
- ✅ emoji_animals (64 animal emoji)
#### Testing
All esoteric alphabets verified:
- ✓ Hieroglyphs round-trip
- ✓ Cuneiform round-trip
- ✓ Domino round-trip
- ✓ Mahjong round-trip
- ✓ Emoji faces round-trip
#### Use Cases
```bash
# Ancient Egyptian
# Cuneiform tablets
# Game encoding
# Emoji messages
```
### Phase 3: Common Alphabets - COMPLETED ✓
#### Implemented (19 total alphabets!)
**RFC 4648 Standards (5):**
- ✅ base16, base32, base32hex, base64, base64url
- ✅ All verified RFC 4648 compliant
- ✅ Proper padding support
**Bitcoin/Blockchain (2):**
- ✅ base58 (Bitcoin addresses)
- ✅ base58flickr (Flickr variant)
**High-Density Encodings (3):**
- ✅ base62 (URL shorteners)
- ✅ base85 (Git pack format)
- ✅ ascii85 (Adobe PDF)
- ✅ z85 (ZeroMQ)
**Human-Oriented (2):**
- ✅ base32_crockford (no ambiguous chars)
- ✅ base32_zbase (human-readable)
**Fun/Creative (4):**
- ✅ cards, dna, binary, hex
**Mathematical Variants (3):**
- ✅ base64_math, hex_math
#### Verification
```bash
# RFC 4648 compliance verified
base32: ✓ Matches `base32` command
base64: ✓ Matches `base64` command
# All alphabets round-trip correctly
base58: ✓
base85: ✓
ascii85: ✓
```
#### Documentation
- Created ALPHABETS.md with complete reference
- Updated README with all 19 alphabets
- Organized by category and use case
### Encoding Modes Feature - COMPLETED ✓
#### Implemented
- ✅ **Dual-mode architecture**
- Mathematical base conversion (default)
- Bit-chunking for RFC compatibility
- ✅ **Mathematical mode** (`base_conversion`)
- Works with any alphabet size
- Treats data as single large number
- No padding needed
- Perfect for creative alphabets (cards, DNA, emoji)
- ✅ **Chunked mode** (`chunked`)
- RFC 4648 compliant
- Fixed-width bit groups
- Supports padding character
- Power-of-2 alphabet sizes only
- ✅ **Configuration in TOML**
- `mode` field specifies algorithm
- `padding` field for chunked mode
- ✅ **Standard base64 support**
- `base64` alphabet with chunked mode
- 100% compatible with RFC 4648
- `base64_math` for mathematical variant
- ✅ **Comprehensive tests** (14 tests passing)
- Both modes tested independently
- Round-trip verification
- Binary data preservation
- RFC compliance verification
#### Examples
```bash
# RFC-compliant base64
# Mathematical base64 (different output)
# Playing cards (mathematical)
```
### Phase 2: CLI Tool - COMPLETED ✓
#### Implemented
- ✅ Command-line interface with `clap`
- `-a, --alphabet <NAME>` to select alphabet (default: cards)
- `-d, --decode` flag to decode instead of encode
- `-l, --list` to list available alphabets
- `[FILE]` optional positional argument for file input
- ✅ Input/output handling
- Reads from stdin if no file provided (pipeable)
- Reads from file if path provided
- Writes encoded output to stdout
- Binary-safe decode output
- ✅ Error handling
- Invalid alphabet names
- File not found
- Invalid UTF-8 in decode mode
- ✅ Comprehensive CLI test suite (8 tests, all passing)
#### Usage Examples
```bash
# List alphabets
base-d --list
# Encode stdin with default (cards) alphabet
# Encode file with DNA alphabet
base-d -a dna input.txt
# Decode
# Round-trip
### Technical Notes
- Bug fixed: `BigUint(0).to_bytes_be()` returns `[0]` not `[]`, affecting zero-byte decoding
- Leading zeros must be preserved through encode/decode cycle
- Base-52 encoding produces ~18 characters for 13-byte input