AI_Printer/README.md

# ESP32-S3 LYF Printer Controller (Wi-Fi REST API)

ESP32-S3 works as a Wi-Fi REST controller and replaces Android App logic:
- REST client -> ESP32-S3 (`esp_http_server`)
- ESP32-S3 -> BLE printer (`lyfPrinter`, `FFF2` write / `FFF1` notify)
- Command compatibility:
  - Print path: `0x00~0x07`
  - OTA path: `0xA0~0xA4`

## Features

- Wi-Fi STA-only mode (configured SSID/password; no SoftAP fallback)
- Built-in web UI at `/` for connect/status, text print, and image upload print
- BLE central client auto-scan/connect to printer name
- Async print queue with jobs (`queued/running/success/failed/canceled`)
- Printer precheck (paper / battery / temperature)
- Built-in UTF-8 text rendering with Chinese support (GB2312 character set, 16x16 bitmap)
- Android-compatible print flow:
  - `0x00` power on
  - `0x03` set print param
  - `0x04` chunked raster send + ACK
  - `0x00` power off
  - `0x02` feed paper
- REST APIs:
  - Health/connection:
    - `GET /v1/health`
    - `POST /v1/printer/connect`
    - `POST /v1/printer/disconnect`
    - `GET /v1/printer/status`
  - Print:
    - `POST /v1/print/raster`
    - `POST /v1/print/image` (direct JPEG binary upload, no base64)
    - `POST /v1/print/qr`
    - `POST /v1/print/text`
    - `POST /v1/print/receipt`
    - `POST /v1/print/label`
  - Jobs:
    - `GET /v1/jobs`
    - `DELETE /v1/jobs`
    - `GET /v1/jobs/{id}`
    - `DELETE /v1/jobs/{id}`
  - Label control:
    - `POST /v1/label/gap_move`
    - `GET /v1/label/offset`
    - `POST /v1/label/offset`
  - OTA:
    - `GET /v1/ota/version`
    - `POST /v1/ota/jump_boot`
    - `POST /v1/ota/jump_app`
    - `POST /v1/ota/erase_page`
    - `POST /v1/ota/write_frame`
    - `POST /v1/ota/upgrade`

## Build

Prerequisites:
- ESP-IDF v5.x
- ESP32-S3 board

```bash
cd ai_printer
idf.py set-target esp32s3
idf.py menuconfig
idf.py build
```

## Config

In `menuconfig -> LYF Controller Config`:
- `LYF_WIFI_SSID`
- `LYF_WIFI_PASSWORD`
- `LYF_HTTP_PORT`
- `LYF_API_KEY` (optional)

When `LYF_API_KEY` is not empty, each request must include:

```text
X-API-Key: <your-key>
```

STA-only behavior:
- If SSID is empty, startup fails.
- If STA connect fails, startup fails (no AP fallback).

## Flash

```bash
cd ai_printer
idf.py -p /dev/tty.usbmodemXXXX flash monitor
```

## Web UI

Open the controller IP in a browser:

```text
http://<esp-ip>/
```

The page provides:
- health/status check
- connect/disconnect printer
- submit a simple text print job
- upload a JPG image (binary payload) and let ESP32-S3 decode/threshold/scale/raster conversion
- view jobs list

If API key is enabled, input it in the page before invoking actions.

## REST Examples

### Health
```bash
curl http://<esp-ip>/v1/health
```

### Connect printer
```bash
curl -X POST http://<esp-ip>/v1/printer/connect \
  -H 'Content-Type: application/json' \
  -d '{"name":"lyfPrinter","timeout_ms":15000}'
```

Auto-match a compatible printer (by BLE service `0xFFF0`):

```bash
curl -X POST http://<esp-ip>/v1/printer/connect \
  -H 'Content-Type: application/json' \
  -d '{"name":"*","timeout_ms":20000}'
```

### Raster print
```bash
curl -X POST http://<esp-ip>/v1/print/raster \
  -H 'Content-Type: application/json' \
  -d '{
    "width":384,
    "height":200,
    "density":"中等",
    "encoding":"base64_msb_1bpp",
    "data":"<BASE64_BYTES>"
  }'
```

### Image print (direct JPG upload, no base64)
```bash
curl -X POST 'http://<esp-ip>/v1/print/image?scale_to_width=1&threshold=160&invert=0&max_height=2200&density=medium' \
  -H 'Content-Type: image/jpeg' \
  --data-binary @./sample.jpg
```

Request constraints:
- Request body limit: 4 MB
- Suggested image size: <= 3 MB when using built-in Web UI uploader

### QR print
```bash
curl -X POST http://<esp-ip>/v1/print/qr \
  -H 'Content-Type: application/json' \
  -d '{
    "text":"https://example.com/pay/123",
    "ecc":"H",
    "module_scale":0,
    "margin_modules":2,
    "density":"中等"
  }'
```

### Text print
```bash
curl -X POST http://<esp-ip>/v1/print/text \
  -H 'Content-Type: application/json' \
  -d '{
    "text":"欢迎使用LYF打印机\\n订单号: A1024\\n谢谢惠顾",
    "density":"中等",
    "scale":2,
    "line_spacing":2,
    "max_height":1800
  }'
```

### Receipt print
```bash
curl -X POST http://<esp-ip>/v1/print/receipt \
  -H 'Content-Type: application/json' \
  -d '{
    "title":"LYF FOOD",
    "density":"中等",
    "footer":"Thanks!",
    "items":[
      {"name":"DishA","qty":2,"price":12.5},
      {"name":"DishB","qty":1,"price":8.0}
    ]
  }'
```

### Label print (with optional gap/offset)
```bash
curl -X POST http://<esp-ip>/v1/print/label \
  -H 'Content-Type: application/json' \
  -d '{
    "width":384,
    "height":260,
    "encoding":"base64_msb_1bpp",
    "data":"<BASE64_BYTES>",
    "gap_move_before":true,
    "offset_tenths_mm":128,
    "density":"中等"
  }'
```

### Jobs
```bash
curl http://<esp-ip>/v1/jobs
curl http://<esp-ip>/v1/jobs/1
curl -X DELETE http://<esp-ip>/v1/jobs/1
curl -X DELETE http://<esp-ip>/v1/jobs -d '{"include_success":true,"include_failed":true,"include_canceled":true}'
```

### Label control
```bash
curl -X POST http://<esp-ip>/v1/label/gap_move
curl http://<esp-ip>/v1/label/offset
curl -X POST http://<esp-ip>/v1/label/offset \
  -H 'Content-Type: application/json' \
  -d '{"offset_tenths_mm":128}'
```

### OTA primitives
```bash
curl http://<esp-ip>/v1/ota/version
curl -X POST http://<esp-ip>/v1/ota/jump_boot
curl -X POST http://<esp-ip>/v1/ota/erase_page -H 'Content-Type: application/json' -d '{"page_num":0}'
curl -X POST http://<esp-ip>/v1/ota/write_frame -H 'Content-Type: application/json' -d '{"packet_num":0,"is_last_frame":false,"data":"<BASE64_<=236_BYTES>"}'
curl -X POST http://<esp-ip>/v1/ota/jump_app
```

### OTA full upgrade
```bash
curl -X POST http://<esp-ip>/v1/ota/upgrade \
  -H 'Content-Type: application/json' \
  -d '{
    "firmware":"<BASE64_FIRMWARE>",
    "jump_boot":true,
    "jump_app":true,
    "page_size":1024,
    "packet_size":236,
    "timeout_ms_per_step":5000
  }'
```

## Notes

- BLE side is central/client role, not printer peripheral role.
- `base64_msb_1bpp` uses Android-compatible bit order (MSB first).
- `/v1/print/image` accepts raw `image/jpeg` bytes directly (no base64 wrapper).
- Large buffers for image upload/decode prefer PSRAM first, then fallback to internal RAM.
- `/v1/print/text` and `/v1/print/receipt` now support UTF-8 Chinese via embedded 16x16 GB2312 glyphs.
- Characters outside embedded glyph set are rendered as square fallback boxes.
- QR encoding uses embedded `qrcodegen` (Project Nayuki C implementation).

## Font Assets

Embedded files:
- `main/domain/assets/fonts/cn16_index.bin`
- `main/domain/assets/fonts/cn16_glyphs.bin`

Regenerate from your own CJK font:

```bash
cd ai_printer
python3 -m pip install --user pillow
python3 tools/gen_cn16_font.py \
  --font app/src/main/assets/fonts/msyh.ttc \
  --font-index 0
```