#!/usr/bin/env python3
"""Update per-ticker archive sync state and pending sync tasks."""

from __future__ import annotations

import argparse
import csv
import sqlite3
from dataclasses import dataclass
from datetime import date, datetime, timedelta, timezone
from pathlib import Path


DEFAULT_DB_PATH = Path("data/hk_ipo.sqlite")
DEFAULT_SCHEMA_PATH = Path("schema/hk_ipo.schema.sql")
SNAPSHOT_DIR = Path("data/snapshots")


@dataclass(frozen=True)
class Ticker:
    ticker: str
    listing_date: str | None
    application_start_date: str | None
    allotment_results_expected_date: str | None


@dataclass(frozen=True)
class StageState:
    ticker: str
    stage: str
    status: str
    required: int
    due_date: str | None
    completed_at: str | None
    last_source_id: str | None
    data_gap_id: str | None
    notes: str


STAGE_ORDER = [
    "T0_prospectus",
    "T1_allotment",
    "T2_grey_market",
    "D1",
    "D5",
    "D20",
    "D60",
]

TASK_TYPES = {
    "T0_prospectus": "archive_prospectus_and_terms",
    "T1_allotment": "archive_allotment_results",
    "T2_grey_market": "archive_grey_market_result",
    "D1": "archive_price_performance",
    "D5": "archive_price_performance",
    "D20": "archive_price_performance",
    "D60": "archive_price_performance",
}


def parse_as_of(value: str | None) -> datetime:
    if value:
        normalized = value.replace("Z", "+00:00")
        return datetime.fromisoformat(normalized)
    return datetime.now(timezone.utc).replace(microsecond=0)


def parse_date(value: str | None) -> date | None:
    if not value:
        return None
    return date.fromisoformat(value)


def due_status(due_date: str | None, as_of_date: date) -> str:
    if due_date is None:
        return "pending_due"
    due = parse_date(due_date)
    if due is None or due <= as_of_date:
        return "pending_due"
    return "pending_not_due"


def query_one(conn: sqlite3.Connection, sql: str, params: tuple[object, ...]) -> sqlite3.Row | None:
    return conn.execute(sql, params).fetchone()


def load_tickers(conn: sqlite3.Connection) -> list[Ticker]:
    rows = conn.execute(
        """
        SELECT ticker, listing_date, application_start_date, allotment_results_expected_date
        FROM ipo_master
        ORDER BY ticker
        """
    ).fetchall()
    return [Ticker(**dict(row)) for row in rows]


def data_gap_for(conn: sqlite3.Connection, ticker: str, stage: str) -> sqlite3.Row | None:
    return query_one(
        conn,
        """
        SELECT gap_id, reason, expected_resolution_date
        FROM data_gaps
        WHERE ticker = ? AND stage = ?
        ORDER BY created_at DESC, gap_id DESC
        LIMIT 1
        """,
        (ticker, stage),
    )


def prospectus_state(conn: sqlite3.Connection, ticker: Ticker, as_of_date: date) -> StageState:
    source = query_one(
        conn,
        """
        SELECT source_id, source_date
        FROM source_refs
        WHERE ticker = ? AND source_type = 'prospectus'
        ORDER BY source_date DESC, source_id DESC
        LIMIT 1
        """,
        (ticker.ticker,),
    )
    terms = query_one(conn, "SELECT ticker FROM offering_terms WHERE ticker = ?", (ticker.ticker,))
    if source and terms:
        return StageState(
            ticker.ticker,
            "T0_prospectus",
            "complete",
            1,
            ticker.application_start_date,
            source["source_date"],
            source["source_id"],
            None,
            "Prospectus source and offering terms are archived.",
        )
    gap = data_gap_for(conn, ticker.ticker, "T0_prospectus")
    status = "blocked" if gap and gap["expected_resolution_date"] is None else due_status(ticker.application_start_date, as_of_date)
    return StageState(
        ticker.ticker,
        "T0_prospectus",
        status,
        1,
        ticker.application_start_date,
        None,
        source["source_id"] if source else None,
        gap["gap_id"] if gap else None,
        "Missing prospectus source or offering terms.",
    )


def allotment_state(conn: sqlite3.Connection, ticker: Ticker, as_of_date: date) -> StageState:
    demand = query_one(
        conn,
        """
        SELECT source_id, stage_date
        FROM ipo_demand
        WHERE ticker = ?
        ORDER BY stage_date DESC, demand_id DESC
        LIMIT 1
        """,
        (ticker.ticker,),
    )
    source = query_one(
        conn,
        """
        SELECT source_id, source_date
        FROM source_refs
        WHERE ticker = ? AND source_type = 'allotment_results'
        ORDER BY source_date DESC, source_id DESC
        LIMIT 1
        """,
        (ticker.ticker,),
    )
    if demand or source:
        return StageState(
            ticker.ticker,
            "T1_allotment",
            "complete",
            1,
            ticker.allotment_results_expected_date,
            (demand or source)["stage_date" if demand else "source_date"],
            (demand or source)["source_id"],
            None,
            "Allotment result facts are archived.",
        )
    gap = data_gap_for(conn, ticker.ticker, "T1_allotment")
    status = "blocked" if gap and gap["expected_resolution_date"] is None else due_status(ticker.allotment_results_expected_date, as_of_date)
    return StageState(
        ticker.ticker,
        "T1_allotment",
        status,
        1,
        ticker.allotment_results_expected_date,
        None,
        None,
        gap["gap_id"] if gap else None,
        "Allotment result facts are not archived yet.",
    )


def price_state(conn: sqlite3.Connection, ticker: Ticker, stage: str, due_date: str | None, as_of_date: date) -> StageState:
    perf = query_one(
        conn,
        """
        SELECT source_id, as_of_date
        FROM price_performance
        WHERE ticker = ? AND stage = ?
        LIMIT 1
        """,
        (ticker.ticker, stage),
    )
    source_types = {
        "T2_grey_market": ("grey_market", "dark_market", "grey_market_performance"),
    }.get(stage, ())
    source = None
    if source_types:
        placeholders = ", ".join("?" for _ in source_types)
        source = query_one(
            conn,
            f"""
            SELECT source_id, source_date
            FROM source_refs
            WHERE ticker = ? AND source_type IN ({placeholders})
            ORDER BY source_date DESC, source_id DESC
            LIMIT 1
            """,
            (ticker.ticker, *source_types),
        )
    if perf or source:
        row = perf or source
        completed_key = "as_of_date" if perf else "source_date"
        return StageState(
            ticker.ticker,
            stage,
            "complete",
            1,
            due_date,
            row[completed_key],
            row["source_id"],
            None,
            "Performance source is archived.",
        )
    gap = data_gap_for(conn, ticker.ticker, stage)
    status = "blocked" if gap and gap["expected_resolution_date"] is None else due_status(due_date, as_of_date)
    note = "Price/performance source is not archived yet."
    if stage in {"D5", "D20", "D60"}:
        note += " Due date uses calendar days until trading-calendar support is added."
    return StageState(
        ticker.ticker,
        stage,
        status,
        1,
        due_date,
        None,
        None,
        gap["gap_id"] if gap else None,
        note,
    )


def listing_offset_due(listing_date: str | None, days_after_listing: int) -> str | None:
    listed = parse_date(listing_date)
    if listed is None:
        return None
    return (listed + timedelta(days=days_after_listing)).isoformat()


def build_states(conn: sqlite3.Connection, ticker: Ticker, as_of_date: date) -> list[StageState]:
    return [
        prospectus_state(conn, ticker, as_of_date),
        allotment_state(conn, ticker, as_of_date),
        price_state(conn, ticker, "T2_grey_market", ticker.listing_date, as_of_date),
        price_state(conn, ticker, "D1", listing_offset_due(ticker.listing_date, 0), as_of_date),
        price_state(conn, ticker, "D5", listing_offset_due(ticker.listing_date, 4), as_of_date),
        price_state(conn, ticker, "D20", listing_offset_due(ticker.listing_date, 19), as_of_date),
        price_state(conn, ticker, "D60", listing_offset_due(ticker.listing_date, 59), as_of_date),
    ]


def upsert_sync_run(conn: sqlite3.Connection, run_id: str, mode: str, as_of: str, status: str, notes: str) -> None:
    conn.execute(
        """
        INSERT INTO sync_runs (sync_run_id, mode, as_of, started_at, finished_at, status, notes)
        VALUES (?, ?, ?, ?, ?, ?, ?)
        ON CONFLICT(sync_run_id) DO UPDATE SET
          mode = excluded.mode,
          as_of = excluded.as_of,
          started_at = excluded.started_at,
          finished_at = excluded.finished_at,
          status = excluded.status,
          notes = excluded.notes
        """,
        (run_id, mode, as_of, as_of, as_of, status, notes),
    )


def replace_state(conn: sqlite3.Connection, states: list[StageState], run_id: str, updated_at: str) -> None:
    conn.executemany(
        """
        INSERT INTO ticker_sync_state (
          ticker, stage, status, required, due_date, completed_at, last_source_id,
          data_gap_id, last_sync_run_id, updated_at, notes
        )
        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
        ON CONFLICT(ticker, stage) DO UPDATE SET
          status = excluded.status,
          required = excluded.required,
          due_date = excluded.due_date,
          completed_at = excluded.completed_at,
          last_source_id = excluded.last_source_id,
          data_gap_id = excluded.data_gap_id,
          last_sync_run_id = excluded.last_sync_run_id,
          updated_at = excluded.updated_at,
          notes = excluded.notes
        """,
        [
            (
                state.ticker,
                state.stage,
                state.status,
                state.required,
                state.due_date,
                state.completed_at,
                state.last_source_id,
                state.data_gap_id,
                run_id,
                updated_at,
                state.notes,
            )
            for state in states
        ],
    )


def rebuild_tasks(conn: sqlite3.Connection, states: list[StageState], run_id: str, updated_at: str) -> None:
    conn.execute("DELETE FROM sync_tasks")
    rows = []
    for state in states:
        if state.status == "complete" or state.required == 0:
            continue
        task_status = {
            "pending_due": "open",
            "pending_not_due": "waiting_until_due",
            "blocked": "blocked",
        }.get(state.status)
        if task_status is None:
            continue
        rows.append(
            (
                f"{state.ticker}_{state.stage}",
                state.ticker,
                state.stage,
                TASK_TYPES[state.stage],
                task_status,
                state.due_date,
                state.data_gap_id,
                run_id,
                updated_at,
                state.notes,
            )
        )
    conn.executemany(
        """
        INSERT INTO sync_tasks (
          task_id, ticker, stage, task_type, task_status, due_date, data_gap_id,
          last_sync_run_id, updated_at, notes
        )
        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
        """,
        rows,
    )


def export_snapshot(conn: sqlite3.Connection, table: str, order_by: str = "1") -> None:
    SNAPSHOT_DIR.mkdir(parents=True, exist_ok=True)
    cursor = conn.execute(f"SELECT * FROM {table} ORDER BY {order_by}")
    columns = [description[0] for description in cursor.description]
    with (SNAPSHOT_DIR / f"{table}.csv").open("w", newline="", encoding="utf-8") as handle:
        writer = csv.writer(handle, lineterminator="\n")
        writer.writerow(columns)
        writer.writerows(cursor.fetchall())


def print_summary(states: list[StageState]) -> None:
    counts: dict[str, int] = {}
    for state in states:
        counts[state.status] = counts.get(state.status, 0) + 1
    print("sync state updated")
    for status in sorted(counts):
        print(f"{status}: {counts[status]}")
    open_items = [state for state in states if state.status in {"pending_due", "blocked"}]
    if open_items:
        print("actionable items:")
        for state in open_items:
            print(f"- {state.ticker} {state.stage}: {state.status} due={state.due_date or ''}")


def main() -> int:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--db", default=str(DEFAULT_DB_PATH), help="Repo-relative SQLite database path.")
    parser.add_argument("--schema", default=str(DEFAULT_SCHEMA_PATH), help="Repo-relative schema path.")
    parser.add_argument("--as-of", help="ISO timestamp for deterministic sync-state snapshots.")
    parser.add_argument("--run-id", help="Stable sync run id. Defaults to sync_state_<timestamp>.")
    parser.add_argument("--mode", default="state_refresh", help="Sync run mode label.")
    args = parser.parse_args()

    as_of_dt = parse_as_of(args.as_of)
    as_of = as_of_dt.isoformat().replace("+00:00", "Z")
    as_of_date = as_of_dt.date()
    run_id = args.run_id or "sync_state_" + as_of.replace(":", "").replace("-", "").replace("+", "").replace("Z", "Z")

    db_path = Path(args.db)
    schema_path = Path(args.schema)
    with sqlite3.connect(db_path) as conn:
        conn.row_factory = sqlite3.Row
        conn.executescript(schema_path.read_text(encoding="utf-8"))
        upsert_sync_run(conn, run_id, args.mode, as_of, "running", "Refreshing derived ticker sync state.")
        states = [state for ticker in load_tickers(conn) for state in build_states(conn, ticker, as_of_date)]
        replace_state(conn, states, run_id, as_of)
        rebuild_tasks(conn, states, run_id, as_of)
        upsert_sync_run(conn, run_id, args.mode, as_of, "complete", "Derived ticker sync state refreshed.")
        export_snapshot(conn, "sync_runs", "sync_run_id")
        export_snapshot(
            conn,
            "ticker_sync_state",
            """
            ticker,
            CASE stage
              WHEN 'T0_prospectus' THEN 0
              WHEN 'T1_allotment' THEN 1
              WHEN 'T2_grey_market' THEN 2
              WHEN 'D1' THEN 3
              WHEN 'D5' THEN 4
              WHEN 'D20' THEN 5
              WHEN 'D60' THEN 6
              ELSE 99
            END
            """,
        )
        export_snapshot(conn, "sync_tasks", "task_status, due_date, ticker, stage")
    print_summary(states)
    return 0


if __name__ == "__main__":
    raise SystemExit(main())