#!/usr/bin/env python3
"""
Generate a complete importable KiCad project for ESP32-S3 Sensor Node.
Creates netlist, component placement guide, and README.
"""
import os, json

PROJ_DIR = os.path.expanduser("~/Documents/KiCad/10.0/esp32-s3-sensor-node")
SCH = os.path.join(PROJ_DIR, "esp32-s3-sensor-node.kicad_sch")
PRO = os.path.join(PROJ_DIR, "esp32-s3-sensor-node.kicad_pro")

NETS = ["GND","3V3","VBUS","EN","IO0","IO12",
        "SDA","SCL","USB_D_P","USB_D_N",
        "CC1","CC2","IO2_LED","D1_A","RXD0","TXD0"]

PASSIVES = [
    ("R1", "Resistor_SMD:R_0603_1608Metric", 55, 30, 0, "IO2_LED", "D1_A", "470"),
    ("R2", "Resistor_SMD:R_0603_1608Metric", 27, 32, 0, "EN", "3V3", "10k"),
    ("R3", "Resistor_SMD:R_0603_1608Metric", 16, 7, 0, "IO0", "3V3", "10k"),
    ("R4", "Resistor_SMD:R_0603_1608Metric", 16, 12, 0, "IO12", "GND", "10k"),
    ("R5", "Resistor_SMD:R_0603_1608Metric", 48, 24, 0, "SDA", "3V3", "4.7k"),
    ("R6", "Resistor_SMD:R_0603_1608Metric", 48, 22, 0, "SCL", "3V3", "4.7k"),
    ("R7", "Resistor_SMD:R_0603_1608Metric", 11, 28, 0, "CC1", "GND", "5.1k"),
    ("R8", "Resistor_SMD:R_0603_1608Metric", 11, 25, 0, "CC2", "GND", "5.1k"),
    ("C1", "Capacitor_SMD:C_0603_1608Metric", 30, 28, 0, "3V3", "GND", "100nF"),
    ("C2", "Capacitor_SMD:C_0603_1608Metric", 30, 25, 0, "3V3", "GND", "100nF"),
    ("C3", "Capacitor_SMD:C_0603_1608Metric", 30, 22, 0, "3V3", "GND", "10uF"),
    ("C4", "Capacitor_SMD:C_0603_1608Metric", 26, 35, 0, "EN", "GND", "100nF"),
    ("C5", "Capacitor_SMD:C_0805_2012Metric", 24, 17, 0, "VBUS", "GND", "10uF"),
    ("C6", "Capacitor_SMD:C_0805_2012Metric", 24, 23, 0, "3V3", "GND", "10uF"),
]

ICS = [
    ("J1", "Connector_USB:USB_C_Receptacle_USB2.0_16P",
     7, 20, 0, "USB-C", [("SH","GND"),("A1","GND"),("A4","VBUS"),
     ("A5","CC1"),("A6","USB_D_P"),("A7","USB_D_N"),("B5","CC2")]),
    ("U2", "Package_TO_SOT_SMD:SOT-223-3Lead_TabPin2",
     20, 20, 0, "AMS1117-3.3", [("1","GND"),("2","3V3"),("3","VBUS")]),
    ("U1", "RF_Module:ESP32-S3-WROOM-1",
     38, 20, 0, "ESP32-S3-WROOM-1", [("1","GND"),("2","3V3"),("3","EN"),
     ("4","SDA"),("5","SCL"),("13","USB_D_N"),("14","USB_D_P"),
     ("20","IO12"),("27","IO0"),("36","RXD0"),("37","TXD0"),("38","IO2_LED")]),
    ("J2", "Connector_PinHeader_2.54mm:PinHeader_1x04_P2.54mm_Vertical",
     56, 20, 0, "I2C_Sensor", [("1","3V3"),("2","SDA"),("3","SCL"),("4","GND")]),
    ("J3", "Connector_PinHeader_2.54mm:PinHeader_1x04_P2.54mm_Vertical",
     25, 3, 0, "PROG", [("1","GND"),("2","RXD0"),("3","TXD0"),("4","3V3")]),
    ("D1", "LED_SMD:LED_0603_1608Metric",
     55, 34, 0, "LED_Green", [("1","GND"),("2","D1_A")]),
]

def create_readme():
    md = f"""# ESP32-S3 Sensor Node — L2.1 Training Exercise

## Project Setup

1. **Open in KiCad 10.0+** — File → Open Project → `{PROJ_DIR}`
2. **Schematic** — Already clean (ERC 0). View in Eeschema.
3. **PCB Layout** — Needs routing. Create board in Pcbnew.

## PCB Spec
- **Size:** 65 × 40mm, 2-layer
- **Stackup:** 1.6mm FR4, 1oz copper, HASL
- **Design rules:** trace/space 0.15mm, drill 0.3mm, annular 0.15mm
- **Target fab:** JLCPCB / PCBWay standard

## Component Placement

```
Board: (0,0) bottom-left, (65,40) top-right

Left edge (x≈5-15):
  J1  USB-C         @ (7, 20)    — left edge, USB mating face outward
  R7  CC1 pull-down @ (11, 28)
  R8  CC2 pull-down @ (11, 25)

Lower-left (x≈15-25, y≈3-15):
  J3  PROG header   @ (25, 3)    — bottom edge
  R3  IO0 pull-up   @ (16, 7)
  R4  IO12 pull-down @ (16, 12)

Center-left (x≈20-30):
  U2  AMS1117-3.3   @ (20, 20)   — regulator
  C5  10µF input    @ (24, 17)   — near U2 pin 3 (VI)
  C6  10µF output   @ (24, 23)   — near U2 pin 2 (VO)

Center (x≈27-38):
  R2  EN pull-up    @ (27, 32)
  C4  EN cap        @ (26, 35)
  C1-C3 decoupling  @ (30, 22-28) — near U1 3V3 pins
  U1  ESP32-S3      @ (38, 20)   — main module

Right side (x≈48-58):
  R5  SDA pull-up   @ (48, 24)
  R6  SCL pull-up   @ (48, 22)
  J2  I2C connector @ (56, 20)   — right edge
  D1  Status LED    @ (55, 34)   — top-right edge
  R1  LED resistor  @ (55, 30)
```

## Antenna Keepout
- **Zone:** x > 46mm, y > 28mm (top-right corner)
- No copper, no traces, no components in this area
- The ESP32-S3-WROOM-1 module has its PCB antenna at the top-right corner

## Routing Order
1. **USB differential pair** — USB_D_P / USB_D_N: 90Ω impedance, length-matched
   - Width: ~0.3mm on 1.6mm FR4 (calc with fab's tool)
   - Gap: ~0.15mm
   - Route on top layer, GND reference on bottom
2. **3V3 power** — 0.5mm traces from U2 VO to U1 3V3 pin + all 3V3 nodes
3. **VBUS power** — 0.5mm from J1 to U2 VI
4. **GND** — Copper pours on both layers with stitching vias
5. **I2C** — SDA/SCL routed together, away from noisy traces
6. **UART** — RXD0/TXD0 to J3
7. **Strapping** — EN, IO0, IO12 to pull resistors
8. **LED** — IO2_LED through R1 to D1

## GND Pour Strategy
- **B.Cu (bottom):** Full copper pour, entire board area
- **F.Cu (top):** Full copper pour EXCEPT antenna keepout zone
- **Antenna keepout:** Keepout zone polygon on both layers (no copper)
- **Stitching vias:** Perimeter every 5mm, plus around module GND pads

## Files
| File | Description |
|------|-------------|
| `*.kicad_sch` | Schematic (ERC 0) |
| `*.kicad_pcb` | PCB layout (empty, needs routing) |
| `*.kicad_pro` | Project file |
| `gen_schematic.py` | Python schematic generator |
| `gen_pcb.py` | Python PCB generator (outline + placement) |
"""
    path = os.path.join(PROJ_DIR, "README.md")
    with open(path, 'w') as f:
        f.write(md)
    print(f"Written: {path}")

def create_placement_csv():
    """Placement file for reference."""
    path = os.path.join(PROJ_DIR, "placement.csv")
    with open(path, 'w') as f:
        f.write("Ref,Footprint,X(mm),Y(mm),Rotation,Net1,Net2\n")
        for ref, fp, x, y, rot, n1, n2, val in PASSIVES:
            f.write(f"{ref},{fp},{x},{y},{rot},{n1},{n2}\n")
        for ref, fp, x, y, rot, val, pins in ICS:
            nets = ", ".join(f"{p[0]}={p[1]}" for p in pins)
            f.write(f"{ref},{fp},{x},{y},{rot},{nets}\n")
    print(f"Written: {path}")

def update_project():
    """Update .kicad_pro with correct board path."""
    # Read existing
    if os.path.exists(PRO):
        with open(PRO) as f:
            config = json.load(f)
    else:
        config = {"board": {}}
    
    # Ensure board settings exist
    config["board"] = config.get("board", {})
    config["board"]["design_settings"] = config["board"].get("design_settings", {})
    
    with open(PRO, 'w') as f:
        json.dump(config, f, indent=2)
    print(f"Updated: {PRO}")

if __name__ == "__main__":
    create_readme()
    create_placement_csv()
    update_project()
    print("\nDone! Open the project in KiCad GUI:")
    print(f"  File → Open Project → {PROJ_DIR}/esp32-s3-sensor-node.kicad_pro")