"""
device_server.py  —  deploy this on the target device (192.168.45.8)

Provides:
  PUT /display   {"state": "on"|"off"}   — blank/unblank framebuffer
  GET /registers                          — read MIPI DSI PHY registers via memtool

Add addresses to REGISTER_COMMANDS to capture more register ranges.
"""

import os
import re
import subprocess

from flask import Flask, jsonify, request

app = Flask(__name__)

# ---------------------------------------------------------------------------
# Register commands to execute on each GET /registers request.
# Each entry is a complete memtool command string.
# ---------------------------------------------------------------------------
REGISTER_COMMANDS = [
    "memtool md -l 0x32e100b4+0x0c",   # DSIM_PHYTIMING / PHYTIMING1 / PHYTIMING2
]

# ---------------------------------------------------------------------------
# SN65DSI83 I2C configuration
# ---------------------------------------------------------------------------
SN65_I2C_BUS  = 2      # i2c-2 on i.MX 8M Mini — change if bridge is on a different bus
SN65_I2C_ADDR = 0x2C   # SN65DSI83 fixed 7-bit I2C address

# Known Samsung DSIM register names (base 0x32E10000, i.MX 8M Mini)
_DSIM_NAMES = {
    0x32e10004: "DSIM_STATUS",
    0x32e10008: "DSIM_CLKCTRL",
    0x32e1000c: "DSIM_TIMEOUT",
    0x32e10010: "DSIM_CONFIG",
    0x32e10014: "DSIM_ESCMODE",
    0x32e100ac: "DSIM_PHYACCHR",
    0x32e100b0: "DSIM_PHYACCHR1",
    0x32e100b4: "DSIM_PHYTIMING",
    0x32e100b8: "DSIM_PHYTIMING1",
    0x32e100bc: "DSIM_PHYTIMING2",
}


def _parse_memtool_output(raw: str) -> list:
    """
    Parse 'memtool md -l' output into a list of dicts.

    Handles both formats:
      32e100b4: 00000001 12345678 ...
      0x32e100b4:  0x00000001  0x12345678 ...
    """
    registers = []
    for line in raw.splitlines():
        line = line.strip()
        if not line:
            continue
        m = re.match(r"(?:0x)?([0-9a-fA-F]+)\s*:\s*(.+)", line)
        if not m:
            continue
        base_addr = int(m.group(1), 16)
        values = re.findall(r"[0-9a-fA-F]{8}", m.group(2))
        for i, val in enumerate(values):
            addr = base_addr + i * 4
            registers.append({
                "address": f"0x{addr:08x}",
                "value":   f"0x{val.lower()}",
                "name":    _DSIM_NAMES.get(addr, ""),
            })
    return registers


# ---------------------------------------------------------------------------
# Routes
# ---------------------------------------------------------------------------

@app.route("/display", methods=["PUT"])
def control_display():
    data  = request.get_json()
    state = data.get("state", "").lower()
    if state == "off":
        os.system("echo 4 > /sys/class/graphics/fb0/blank")
        return jsonify({"status": "Display OFF"}), 200
    elif state == "on":
        os.system("echo 0 > /sys/class/graphics/fb0/blank")
        return jsonify({"status": "Display ON"}), 200
    else:
        return jsonify({"error": "Invalid state. Use 'on' or 'off'"}), 400


@app.route("/registers", methods=["GET"])
def get_registers():
    """Read MIPI DSI PHY timing registers via memtool and return JSON."""
    all_registers = []
    raw_lines     = []
    errors        = []

    for cmd_str in REGISTER_COMMANDS:
        try:
            result = subprocess.run(
                cmd_str.split(), capture_output=True, text=True, timeout=5
            )
            raw = result.stdout.strip()
            if raw:
                raw_lines.append(raw)
                all_registers.extend(_parse_memtool_output(raw))
            if result.returncode != 0 and result.stderr.strip():
                errors.append(f"{cmd_str}: {result.stderr.strip()}")
        except FileNotFoundError:
            errors.append(f"{cmd_str}: memtool not found in PATH")
        except subprocess.TimeoutExpired:
            errors.append(f"{cmd_str}: timed out after 5 s")
        except Exception as e:
            errors.append(f"{cmd_str}: {e}")

    return jsonify({
        "commands":  REGISTER_COMMANDS,
        "registers": all_registers,
        "raw":       "\n".join(raw_lines),
        "errors":    errors if errors else None,
    }), 200


def _i2c_read_byte(bus: int, addr: int, reg: int) -> int | None:
    """Read one byte from an I2C device using i2cget. Returns None on failure."""
    try:
        result = subprocess.run(
            ["i2cget", "-y", str(bus), f"0x{addr:02x}", f"0x{reg:02x}"],
            capture_output=True, text=True, timeout=3
        )
        if result.returncode == 0:
            return int(result.stdout.strip(), 16)
    except Exception:
        pass
    return None


@app.route("/sn65_registers", methods=["GET"])
def get_sn65_registers():
    """Read SN65DSI83 CSR 0x0A (PLL/CLK status) and 0xE5 (error flags) via I2C."""
    csr_0a = _i2c_read_byte(SN65_I2C_BUS, SN65_I2C_ADDR, 0x0A)
    csr_e5 = _i2c_read_byte(SN65_I2C_BUS, SN65_I2C_ADDR, 0xE5)

    regs   = {}
    errors = []

    if csr_0a is not None:
        regs["csr_0a"] = {
            "value":    f"0x{csr_0a:02x}",
            "pll_lock": bool(csr_0a & 0x80),   # bit 7: PLL_EN_STAT (powered + locked)
            "clk_det":  bool(csr_0a & 0x40),   # bit 6: high-speed CLK lane detected
        }
    else:
        errors.append("CSR 0x0A: i2cget failed")

    if csr_e5 is not None:
        regs["csr_e5"] = {
            "value":           f"0x{csr_e5:02x}",
            "pll_unlock":      bool(csr_e5 & 0x01),  # default=1 at reset; must clear after init
            "cha_sot_bit_err": bool(csr_e5 & 0x04),
            "cha_llp_err":     bool(csr_e5 & 0x08),  # SoT/EoT/lane-merge error
            "cha_ecc_err":     bool(csr_e5 & 0x10),
            "cha_lp_err":      bool(csr_e5 & 0x20),
            "cha_crc_err":     bool(csr_e5 & 0x40),
        }
    else:
        errors.append("CSR 0xE5: i2cget failed")

    return jsonify({
        "i2c_bus":   SN65_I2C_BUS,
        "i2c_addr":  f"0x{SN65_I2C_ADDR:02x}",
        "registers": regs,
        "errors":    errors if errors else None,
    }), 200


if __name__ == "__main__":
    app.run(host="0.0.0.0", port=5000)