"""
minimateplus/bw_ascii_report.py — parser for Blastware's per-event ASCII
report (the .TXT file BW writes alongside each saved event binary).

The ASCII export is the authoritative source for every "rich" per-event
field that BW computes from the waveform but never persists in the BW
binary itself:

  - Per-channel PPV (Tran / Vert / Long / MicL)
  - Peak Vector Sum + Peak Vector Sum Time
  - Per-channel ZC Freq, Time of Peak, Peak Acceleration, Peak Displacement
  - MicL PSPL, MicL Time of Peak, MicL ZC Freq
  - Per-channel Sensor Self-Check (Test Freq / Test Ratio / Test Results)
  - MicL Test Amplitude (mV)
  - Battery, calibration date, monitor-log timestamps

Persisting these values into the SFM database lets the monthly-summary
review workflow ("show me events at Location X with PVS > 0.5") work
without depending on the (still-undecoded) waveform body codec.

Format (verified against decode-re/5-8-26 4-event bundle):

  - One field per line, wrapped in double quotes:   `"Field Name : Value"`
  - Field/value separator: literal ` : ` (space-colon-space).
  - Some field names contain an internal `:` already (e.g. `"Project:"`),
    so we split on the FIRST ` : ` only.
  - Some fields have unit suffixes:  `"0.500 in/s"` / `"7.5 Hz"` / `"533 mv"`.
  - A `"Monitor Log(s)"` marker line is followed by tab-separated rows
    of `start_time<TAB>stop_time<TAB>description`.
  - Final `"PC SW Version : ..."` line ends the metadata block.
  - A blank line separates metadata from the sample table.
  - Sample table starts with `   Tran   <TAB>   Vert   <TAB>...`, then
    one row per sample (tab-separated, right-padded numeric values).
  - Geo channel values are in in/s; MicL in dB(L) (or 0.000 below threshold).

Because some metadata fields have whitespace quirks ("MicL  Time of
Peak" has two spaces; the leading "Project:" value has its own colon),
we normalise whitespace in the key before lookup.
"""

from __future__ import annotations

import datetime
import re
from dataclasses import dataclass, field
from pathlib import Path
from typing import Dict, List, Optional, Tuple, Union


# ─────────────────────────────────────────────────────────────────────────────
# Output dataclasses
# ─────────────────────────────────────────────────────────────────────────────


@dataclass
class ChannelStats:
    """Per-channel derived stats, populated from an event report."""
    ppv_ips:           Optional[float] = None      # in/s            (geo channels only)
    zc_freq_hz:        Optional[float] = None      # Hz
    time_of_peak_s:    Optional[float] = None      # seconds (relative to trigger; can be negative)
    peak_accel_g:      Optional[float] = None      # g               (geo channels only)
    peak_disp_in:      Optional[float] = None      # in              (geo channels only)


@dataclass
class MicStats:
    """MicL-specific stats."""
    weighting:         Optional[str]   = None      # e.g. "Linear Weighting"
    pspl_dbl:          Optional[float] = None      # dB(L)
    zc_freq_hz:        Optional[float] = None
    time_of_peak_s:    Optional[float] = None


@dataclass
class SensorCheck:
    """Per-channel sensor self-check result.

    Geo channels report a frequency + ratio; MicL reports a frequency +
    amplitude (mV).  All channels also have a Pass/Fail string.
    """
    test_freq_hz:      Optional[float] = None
    test_ratio:        Optional[float] = None      # geo channels only
    test_amplitude_mv: Optional[float] = None      # MicL only
    test_results:      Optional[str]   = None      # "Passed" / "Failed"


@dataclass
class MonitorLogEntry:
    """One row of the trailing Monitor Log(s) block."""
    start_time:  Optional[datetime.datetime] = None
    stop_time:   Optional[datetime.datetime] = None
    description: Optional[str] = None


@dataclass
class BwAsciiReport:
    """Structured representation of one BW per-event ASCII export."""
    # ── Identity ─────────────────────────────────────────────────────────────
    event_type:        Optional[str] = None         # e.g. "Full Waveform"
    serial:            Optional[str] = None         # e.g. "BE11529"
    version:           Optional[str] = None         # firmware version line
    file_name:         Optional[str] = None         # e.g. "M529LK44.AB0"
    event_datetime:    Optional[datetime.datetime] = None  # parsed from Event Time + Event Date

    # ── Trigger / recording config ──────────────────────────────────────────
    trigger_channel:        Optional[str]   = None  # e.g. "Vert" or "From Unit"
    geo_trigger_level_ips:  Optional[float] = None
    pretrig_s:              Optional[float] = None  # negative seconds
    record_time_s:          Optional[float] = None
    record_stop_mode:       Optional[str]   = None
    sample_rate_sps:        Optional[int]   = None
    battery_volts:          Optional[float] = None
    calibration_date:       Optional[datetime.date] = None
    calibration_by:         Optional[str]   = None  # e.g. "Instantel"
    units:                  Optional[str]   = None  # e.g. "in/s and dB(L)"

    # ── Operator-supplied metadata ──────────────────────────────────────────
    project:           Optional[str] = None
    client:            Optional[str] = None
    operator:          Optional[str] = None         # User Name
    sensor_location:   Optional[str] = None         # Seis Loc

    # ── Geo channel scaling ─────────────────────────────────────────────────
    geo_range_ips:     Optional[float] = None       # 10.000 / 1.250

    # ── Per-channel derived stats (geo + mic) ───────────────────────────────
    channels:          Dict[str, ChannelStats] = field(default_factory=dict)
    mic:               MicStats = field(default_factory=MicStats)

    # ── Vector sum ──────────────────────────────────────────────────────────
    peak_vector_sum_ips:    Optional[float] = None
    peak_vector_sum_time_s: Optional[float] = None

    # ── Sensor self-check (per channel) ─────────────────────────────────────
    sensor_check:      Dict[str, SensorCheck] = field(default_factory=dict)

    # ── Monitor log + tooling version ───────────────────────────────────────
    monitor_log:       List[MonitorLogEntry] = field(default_factory=list)
    pc_sw_version:     Optional[str] = None

    # ── Sample table (optional; only parsed if requested) ───────────────────
    # Each entry: (Tran, Vert, Long, MicL) in the report's units (geo
    # channels in in/s, MicL in dB(L)).  None when parse_samples=False.
    samples:           Optional[List[Tuple[float, float, float, float]]] = None


# ─────────────────────────────────────────────────────────────────────────────
# Helpers
# ─────────────────────────────────────────────────────────────────────────────


_KEY_NORMALISE_RE = re.compile(r"\s+")
_NUMERIC_RE       = re.compile(r"^-?\d+(?:\.\d+)?")


def _normalise_key(k: str) -> str:
    """Collapse whitespace runs (incl. tabs) and strip — handles BW's
    "MicL  Time of Peak" double-space and leading-colon quirks."""
    return _KEY_NORMALISE_RE.sub(" ", k).strip()


def _strip_quotes(line: str) -> str:
    line = line.rstrip("\r\n")
    if len(line) >= 2 and line.startswith('"') and line.endswith('"'):
        return line[1:-1]
    return line


def _parse_number(value: str) -> Optional[float]:
    """Pull the leading numeric portion out of a value like "0.500 in/s"."""
    m = _NUMERIC_RE.match(value.strip())
    if not m:
        return None
    try:
        return float(m.group(0))
    except ValueError:
        return None


def _parse_int(value: str) -> Optional[int]:
    n = _parse_number(value)
    return None if n is None else int(round(n))


# Months exactly as BW writes them.
_MONTHS = {
    "January": 1, "February": 2, "March": 3, "April": 4,
    "May": 5, "June": 6, "July": 7, "August": 8,
    "September": 9, "October": 10, "November": 11, "December": 12,
    # Short forms used in monitor-log rows ("Apr 23 /26").
    "Jan": 1, "Feb": 2, "Mar": 3, "Apr": 4, "Jun": 6, "Jul": 7,
    "Aug": 8, "Sep": 9, "Oct": 10, "Nov": 11, "Dec": 12,
}


def _parse_event_date(s: str) -> Optional[datetime.date]:
    """Parse "April 23, 2026" or "May 8, 2026" → date."""
    s = s.strip()
    parts = s.replace(",", " ").split()
    if len(parts) < 3:
        return None
    month_name, day_str, year_str = parts[0], parts[1], parts[2]
    month = _MONTHS.get(month_name)
    if month is None:
        return None
    try:
        return datetime.date(int(year_str), month, int(day_str))
    except ValueError:
        return None


def _parse_event_time(s: str) -> Optional[datetime.time]:
    """Parse "15:56:35" → time."""
    s = s.strip()
    try:
        h, m, sec = s.split(":")
        return datetime.time(int(h), int(m), int(sec))
    except (ValueError, IndexError):
        return None


def _parse_calibration(value: str) -> Tuple[Optional[datetime.date], Optional[str]]:
    """Parse "April 29, 2025 by Instantel" → (date, "Instantel")."""
    parts = value.split(" by ", 1)
    date = _parse_event_date(parts[0])
    by = parts[1].strip() if len(parts) > 1 else None
    return date, by


def _parse_monitor_row(line: str) -> Optional[MonitorLogEntry]:
    """Parse a tab-separated monitor log row.

    Format: `<start>\t<stop>\t<desc>` where each timestamp is BW's
    short form "Mon DD /YY HH:MM:SS" (e.g. "Apr 23 /26 15:46:16").
    Year is encoded as a 2-digit suffix; we expand "/26" → 2026.
    """
    parts = line.split("\t")
    if len(parts) < 2:
        return None
    start = _parse_monitor_ts(parts[0])
    stop  = _parse_monitor_ts(parts[1])
    desc  = parts[2].strip() if len(parts) > 2 else None
    if start is None and stop is None and not desc:
        return None
    return MonitorLogEntry(start_time=start, stop_time=stop, description=desc)


def _parse_monitor_ts(s: str) -> Optional[datetime.datetime]:
    """Parse "Apr 23 /26 15:46:16" → datetime."""
    s = s.strip()
    parts = s.split()
    if len(parts) < 4:
        return None
    month = _MONTHS.get(parts[0])
    if month is None:
        return None
    try:
        day = int(parts[1])
        # parts[2] looks like "/26" → century-flip to 2026
        yy = int(parts[2].lstrip("/"))
        year = 2000 + yy if yy < 80 else 1900 + yy
        h, m, sec = (int(x) for x in parts[3].split(":"))
        return datetime.datetime(year, month, day, h, m, sec)
    except (ValueError, IndexError):
        return None


# ─────────────────────────────────────────────────────────────────────────────
# Top-level parser
# ─────────────────────────────────────────────────────────────────────────────


def parse_report(text: Union[str, bytes], *, parse_samples: bool = False) -> BwAsciiReport:
    """Parse a BW per-event ASCII export into a structured BwAsciiReport.

    Set ``parse_samples=True`` to also populate ``report.samples`` with
    the trailing sample table.  Default False because the table is
    huge and most callers only want metadata for indexing.
    """
    if isinstance(text, bytes):
        text = text.decode("ascii", errors="replace")

    report = BwAsciiReport()
    # Pre-create channel stat slots so callers can rely on them existing.
    for ch in ("Tran", "Vert", "Long", "MicL"):
        report.channels.setdefault(ch, ChannelStats())
        report.sensor_check.setdefault(ch, SensorCheck())

    lines = text.splitlines()
    i = 0
    n = len(lines)

    in_monitor_log_section = False
    event_time_str: Optional[str] = None
    event_date: Optional[datetime.date] = None

    while i < n:
        raw_line = lines[i]
        i += 1
        # Blank line marks the start of the sample table.
        if raw_line.strip() == "":
            break

        line = _strip_quotes(raw_line)

        # Monitor log section: "Monitor Log(s)" header followed by N rows
        # (still inside double-quoted lines), terminated by a non-row line
        # like "PC SW Version : ..." or a blank line.
        if not in_monitor_log_section and line.strip() == "Monitor Log(s)":
            in_monitor_log_section = True
            continue
        if in_monitor_log_section:
            # Heuristic: monitor rows contain a tab; the next "Field : Value"
            # line ends the section.
            if "\t" in line:
                entry = _parse_monitor_row(line)
                if entry:
                    report.monitor_log.append(entry)
                continue
            # Falls through to the field parser below; clear the flag.
            in_monitor_log_section = False

        # "Field : Value" — split on FIRST occurrence of " : "
        idx = line.find(" : ")
        if idx < 0:
            continue
        key = _normalise_key(line[:idx])
        value = line[idx + 3 :].strip()

        # ── Identity / config ────────────────────────────────────────────────
        if   key == "Event Type":           report.event_type = value
        elif key == "Serial Number":        report.serial = value
        elif key == "Version":              report.version = value
        elif key == "File Name":            report.file_name = value
        elif key == "Event Time":           event_time_str = value
        elif key == "Event Date":           event_date = _parse_event_date(value)

        elif key == "Trigger":              report.trigger_channel = value
        elif key == "Geo Trigger Level":    report.geo_trigger_level_ips = _parse_number(value)
        elif key == "Pre-trigger Length":   report.pretrig_s = _parse_number(value)
        elif key == "Record Time":          report.record_time_s = _parse_number(value)
        elif key == "Record Stop Mode":     report.record_stop_mode = value
        elif key == "Sample Rate":          report.sample_rate_sps = _parse_int(value)
        elif key == "Battery Level":        report.battery_volts = _parse_number(value)
        elif key == "Calibration":
            report.calibration_date, report.calibration_by = _parse_calibration(value)
        elif key == "Units":                report.units = value

        # Project labels in BW carry their own trailing colon — after
        # _normalise_key we just strip it for matching.
        elif key.rstrip(":") == "Project":  report.project = value
        elif key.rstrip(":") == "Client":   report.client = value
        elif key.rstrip(":") == "User Name":report.operator = value
        elif key.rstrip(":") == "Seis Loc": report.sensor_location = value

        elif key == "Geo Range":            report.geo_range_ips = _parse_number(value)

        # ── Per-channel stats ────────────────────────────────────────────────
        # All match the pattern "{Channel} <stat-name>"
        elif key in (
            "Tran PPV", "Vert PPV", "Long PPV",
            "Tran ZC Freq", "Vert ZC Freq", "Long ZC Freq",
            "Tran Time of Peak", "Vert Time of Peak", "Long Time of Peak",
            "Tran Peak Acceleration", "Vert Peak Acceleration", "Long Peak Acceleration",
            "Tran Peak Displacement", "Vert Peak Displacement", "Long Peak Displacement",
        ):
            ch_name, stat = key.split(" ", 1)
            cs = report.channels.setdefault(ch_name, ChannelStats())
            num = _parse_number(value)
            if   stat == "PPV":                 cs.ppv_ips        = num
            elif stat == "ZC Freq":             cs.zc_freq_hz     = num
            elif stat == "Time of Peak":        cs.time_of_peak_s = num
            elif stat == "Peak Acceleration":   cs.peak_accel_g   = num
            elif stat == "Peak Displacement":   cs.peak_disp_in   = num

        # ── Vector Sum ───────────────────────────────────────────────────────
        elif key == "Peak Vector Sum":
            report.peak_vector_sum_ips = _parse_number(value)
        elif key == "Peak Vector Sum Time":
            report.peak_vector_sum_time_s = _parse_number(value)

        # ── Microphone block ────────────────────────────────────────────────
        elif key == "Microphone":
            report.mic.weighting = value
        elif key == "MicL PSPL":
            report.mic.pspl_dbl = _parse_number(value)
            # Mirror onto the "MicL" entry in channels so callers querying
            # `channels["MicL"].ppv_ips` see something — but it's dB(L), not
            # in/s, so we store as-is in the MicStats and mark the channel.
        elif key == "MicL Time of Peak":
            report.mic.time_of_peak_s = _parse_number(value)
            cs = report.channels.setdefault("MicL", ChannelStats())
            cs.time_of_peak_s = report.mic.time_of_peak_s
        elif key == "MicL ZC Freq":
            report.mic.zc_freq_hz = _parse_number(value)
            cs = report.channels.setdefault("MicL", ChannelStats())
            cs.zc_freq_hz = report.mic.zc_freq_hz

        # ── Sensor self-check ────────────────────────────────────────────────
        elif key in (
            "Tran Test Freq", "Vert Test Freq", "Long Test Freq", "MicL Test Freq",
            "Tran Test Ratio", "Vert Test Ratio", "Long Test Ratio",
            "MicL Test Amplitude",
            "Tran Test Results", "Vert Test Results", "Long Test Results", "MicL Test Results",
        ):
            ch_name, stat = key.split(" ", 1)
            sc = report.sensor_check.setdefault(ch_name, SensorCheck())
            if   stat == "Test Freq":      sc.test_freq_hz      = _parse_number(value)
            elif stat == "Test Ratio":     sc.test_ratio        = _parse_number(value)
            elif stat == "Test Amplitude": sc.test_amplitude_mv = _parse_number(value)
            elif stat == "Test Results":   sc.test_results      = value

        # ── Trailer ─────────────────────────────────────────────────────────
        elif key == "PC SW Version":
            report.pc_sw_version = value

        # Unknown keys are silently dropped — forward-compat for future
        # BW versions that may add fields.

    # Combine event date + time into a datetime
    if event_date is not None and event_time_str is not None:
        t = _parse_event_time(event_time_str)
        if t is not None:
            report.event_datetime = datetime.datetime.combine(event_date, t)

    if parse_samples:
        report.samples = _parse_sample_table(lines, i)

    return report


def _parse_sample_table(
    lines: List[str], start: int,
) -> List[Tuple[float, float, float, float]]:
    """Parse the trailing sample table.

    The table starts with a header row ("   Tran   <TAB>...") and continues
    until EOF.  Each data row is a tab-separated quartet of numeric values.
    """
    samples: List[Tuple[float, float, float, float]] = []
    seen_header = False
    for line in lines[start:]:
        line = line.rstrip("\r\n")
        if not line.strip():
            continue
        cols = [c.strip() for c in line.split("\t") if c.strip()]
        if not seen_header:
            # Header row contains channel names; numeric rows don't.
            if any(c in ("Tran", "Vert", "Long", "MicL") for c in cols):
                seen_header = True
            continue
        if len(cols) < 4:
            continue
        try:
            samples.append((
                float(cols[0]), float(cols[1]),
                float(cols[2]), float(cols[3]),
            ))
        except ValueError:
            continue
    return samples


def parse_report_file(
    path: Union[str, Path], *, parse_samples: bool = False,
) -> BwAsciiReport:
    """Convenience: read a .TXT file from disk and parse it."""
    return parse_report(Path(path).read_bytes(), parse_samples=parse_samples)