import csv
import math
from pathlib import Path

# -----------------------
# CONFIG
# -----------------------
CSV_PATH = "conveyors.csv"
OUT_TSCN = "generated_conveyors.tscn"

SCALE = 0.0254          # AutoCAD units → Godot units
FIXED_Y = 2.5

BELT_RESOURCE_ID = "3_38ygf"  # BeltConveyorAssembly.tscn

# -----------------------
# HELPERS
# -----------------------
def transform_from_points(x1, y1, x2, y2):
    dx = x2 - x1
    dy = y2 - y1

    length = math.hypot(dx, dy) * SCALE
    angle = math.atan2(dy, dx)

    mid_x = (x1 + x2) / 2 * SCALE
    mid_z = (y1 + y2) / 2 * SCALE  # if you need flip: mid_z = -(y1 + y2)/2 * SCALE

    return {
        "length": length,
        "pos": (mid_x, FIXED_Y, mid_z),
        "rot_y": -angle
    }

def transform3d(rot_y, x, y, z):
    c = math.cos(rot_y)
    s = math.sin(rot_y)
    return (
        f"Transform3D({c}, 0, {s}, "
        f"0, 1, 0, "
        f"{-s}, 0, {c}, "
        f"{x}, {y}, {z})"
    )

# -----------------------
# READ CSV
# -----------------------
conveyors = []
skipped = []  # (key, reason)

def is_blank(v):
    return v is None or str(v).strip() == ""

with open(CSV_PATH, newline="") as f:
    reader = csv.DictReader(f)
    for row in reader:
        key = (row.get("conveyor_key") or "").strip()

        included = (row.get("included") or "1").strip()
        if included == "0":
            skipped.append((key, "included=0 (no geometry)"))
            continue

        # guard against blank coords
        for col in ("start_x", "start_y", "end_x", "end_y"):
            if is_blank(row.get(col)):
                skipped.append((key, f"blank {col}"))
                break
        else:
            try:
                x1 = float(row["start_x"])
                y1 = float(row["start_y"])
                x2 = float(row["end_x"])
                y2 = float(row["end_y"])
            except ValueError as e:
                skipped.append((key, f"float parse error: {e}"))
                continue

            conv = transform_from_points(x1, y1, x2, y2)
            conv["name"] = key
            conveyors.append(conv)

# optional: write a simple report so you can see what spurs are missing
Path("skipped_conveyors.txt").write_text(
    "\n".join([f"{k}\t{r}" for k, r in skipped]),
    encoding="utf-8"
)

# -----------------------
# WRITE TSCN
# -----------------------
lines = []
lines.append('[gd_scene load_steps=2 format=3]')
lines.append('')
lines.append(
    '[ext_resource type="PackedScene" path="res://parts/assemblies/BeltConveyorAssembly.tscn" id="3_38ygf"]'
)
lines.append('')
lines.append('[node name="GeneratedConveyors" type="Node3D"]')
lines.append('')

for c in conveyors:
    x, y, z = c["pos"]
    t = transform3d(c["rot_y"], x, y, z)

    lines.append(f'[node name="{c["name"]}" parent="." instance=ExtResource("{BELT_RESOURCE_ID}")]')
    lines.append(f"transform = {t}")
    lines.append("right_side_guards_enabled = false")
    lines.append("left_side_guards_enabled = false")
    lines.append("head_end_leg_enabled = false")
    lines.append("tail_end_leg_enabled = false")
    lines.append("enable_comms = true")
    lines.append(f'speed_tag_name = "{c["name"]}_OIP"')
    lines.append(f"size = Vector3({c['length']:.6f}, 0.5, 1.524)")
    lines.append("")

Path(OUT_TSCN).write_text("\n".join(lines), encoding="utf-8")
print(f"Generated: {OUT_TSCN}")
print(f"Skipped: {len(skipped)} (see skipped_conveyors.txt)")