#!/usr/bin/env python3
"""
Clamp VerifiedBuild literals to signed MEDIUMINT range for DBs that still use
MEDIUMINT on VerifiedBuild (see data/sql/old/db_world/8.x/2022_10_30_01.sql).

Processes INSERT (explicit column lists) and simple UPDATE ... VerifiedBuild = N.
"""
from __future__ import annotations

import re
import sys
from pathlib import Path

MAX_SIGNED_MEDIUMINT = 8388607
MIN_SIGNED_MEDIUMINT = -8388608

INSERT_RE = re.compile(
    r"INSERT\s+INTO\s+`(?P<table>\w+)`\s*\((?P<cols>[^)]+)\)\s*VALUES\s*",
    re.IGNORECASE,
)

# Base dumps: full row order ends with VerifiedBuild (6- or 8-column layouts).
INSERT_SPELL_TP_VALUES_RE = re.compile(
    r"INSERT\s+INTO\s+`spell_target_position`\s*VALUES\s*",
    re.IGNORECASE,
)

STMT_START = (
    "INSERT ",
    "DELETE ",
    "UPDATE ",
    "ALTER ",
    "DROP ",
    "CREATE ",
    "SET ",
    "REPLACE ",
)


def split_fields(inner: str) -> list[str]:
    fields: list[str] = []
    cur: list[str] = []
    depth = 0
    in_str = False
    str_ch = ""
    esc = False
    for ch in inner:
        if in_str:
            cur.append(ch)
            if esc:
                esc = False
            elif ch == "\\":
                esc = True
            elif ch == str_ch:
                in_str = False
            continue
        if ch in "'\"":
            in_str = True
            str_ch = ch
            cur.append(ch)
            continue
        if ch == "(":
            depth += 1
        elif ch == ")":
            depth -= 1
        if ch == "," and depth == 0:
            fields.append("".join(cur).strip())
            cur = []
        else:
            cur.append(ch)
    fields.append("".join(cur).strip())
    return fields


def join_fields(fields: list[str]) -> str:
    return ", ".join(fields)


def clamp_tuple(tuple_str: str, vb_idx: int) -> str:
    t = tuple_str.strip()
    if not (t.startswith("(") and t.endswith(")")):
        return tuple_str
    fields = split_fields(t[1:-1])
    if vb_idx >= len(fields):
        return tuple_str
    raw = fields[vb_idx].strip()
    if not re.fullmatch(r"-?\d+", raw):
        return tuple_str
    n = int(raw)
    if MIN_SIGNED_MEDIUMINT <= n <= MAX_SIGNED_MEDIUMINT:
        return tuple_str
    fields[vb_idx] = "0"
    return "(" + join_fields(fields) + ")"


def process_value_segment(segment: str, vb_idx: int) -> tuple[str, int]:
    out: list[str] = []
    changes = 0
    i, n = 0, len(segment)
    while i < n:
        if segment[i] == "(":
            depth = 1
            j = i + 1
            while j < n and depth > 0:
                if segment[j] == "(":
                    depth += 1
                elif segment[j] == ")":
                    depth -= 1
                j += 1
            tup = segment[i:j]
            new_tup = clamp_tuple(tup, vb_idx)
            if new_tup != tup:
                changes += 1
            out.append(new_tup)
            i = j
            continue
        out.append(segment[i])
        i += 1
    return "".join(out), changes


def clamp_update_verifiedbuild(line: str) -> tuple[str, int]:
    changes = 0

    def repl(m: re.Match[str]) -> str:
        nonlocal changes
        num = m.group(1)
        n = int(num)
        if MIN_SIGNED_MEDIUMINT <= n <= MAX_SIGNED_MEDIUMINT:
            return m.group(0)
        changes += 1
        return f"`VerifiedBuild` = 0"

    new_line = re.sub(
        r"`VerifiedBuild`\s*=\s*([0-9]+)",
        repl,
        line,
        flags=re.IGNORECASE,
    )
    return new_line, changes


def first_tuple_vb_index(segment: str) -> int | None:
    i, n = 0, len(segment)
    while i < n:
        if segment[i] == "(":
            depth = 1
            j = i + 1
            while j < n and depth > 0:
                if segment[j] == "(":
                    depth += 1
                elif segment[j] == ")":
                    depth -= 1
                j += 1
            tup = segment[i:j]
            fields = split_fields(tup[1:-1])
            if fields:
                return len(fields) - 1
            return None
        i += 1
    return None


def process_sql_text(text: str) -> tuple[str, int]:
    lines = text.splitlines(keepends=True)
    out: list[str] = []
    mode: str | None = None
    vb_idx = 0
    total_changes = 0

    for line in lines:
        nl, ch = clamp_update_verifiedbuild(line)
        total_changes += ch
        line = nl

        stripped = line.lstrip()

        if mode == "insert_values":
            if stripped and not stripped.startswith("(") and not stripped.startswith("--"):
                if any(stripped.startswith(p) for p in STMT_START):
                    mode = None

        if mode == "spell_tp_values":
            if stripped and not stripped.startswith("(") and not stripped.startswith("--"):
                if any(stripped.startswith(p) for p in STMT_START):
                    mode = None

        if mode is None:
            m = INSERT_RE.search(line)
            if m and "`VerifiedBuild`" in m.group("cols"):
                cols = [c.strip().strip("`") for c in m.group("cols").split(",")]
                vb_idx = cols.index("VerifiedBuild")
                mode = "insert_values"
                prefix = line[: m.end()]
                suffix = line[m.end() :]
                if suffix.strip():
                    new_suf, ch2 = process_value_segment(suffix, vb_idx)
                    total_changes += ch2
                    line = prefix + new_suf
                if ");" in line or line.rstrip().endswith(");"):
                    mode = None
                out.append(line)
                continue
            m2 = INSERT_SPELL_TP_VALUES_RE.search(line)
            if m2:
                mode = "spell_tp_values"
                vb_idx = -1
                prefix = line[: m2.end()]
                suffix = line[m2.end() :]
                if suffix.strip():
                    vb_idx = first_tuple_vb_index(suffix)
                    if vb_idx is None:
                        vb_idx = 7
                    new_suf, ch2 = process_value_segment(suffix, vb_idx)
                    total_changes += ch2
                    line = prefix + new_suf
                if ");" in line or line.rstrip().endswith(");"):
                    mode = None
                out.append(line)
                continue
            out.append(line)
            continue

        if mode == "spell_tp_values":
            if vb_idx < 0:
                vb_idx = first_tuple_vb_index(line)
                if vb_idx is None:
                    vb_idx = 7
            new_line, ch3 = process_value_segment(line, vb_idx)
            total_changes += ch3
            out.append(new_line)
            if ");" in line or line.rstrip().endswith(");"):
                mode = None
            continue

        # insert_values continuation
        new_line, ch3 = process_value_segment(line, vb_idx)
        total_changes += ch3
        out.append(new_line)
        if ");" in line or line.rstrip().endswith(");"):
            mode = None

    return "".join(out), total_changes


def main() -> int:
    sql_root = Path(__file__).resolve().parents[1]
    roots = [
        sql_root / "archive" / "db_world",
        sql_root / "updates" / "db_world",
        sql_root / "base" / "db_world",
    ]
    file_count = 0
    change_lines = 0
    for root in roots:
        if not root.exists():
            continue
        for path in sorted(root.glob("*.sql")):
            text = path.read_text(encoding="utf-8", errors="strict")
            new_text, ch = process_sql_text(text)
            if ch:
                path.write_text(new_text, encoding="utf-8")
                change_lines += ch
                file_count += 1
                print(f"{path.relative_to(sql_root)}: {ch} change(s)")
    print(f"Done. {file_count} file(s) written, {change_lines} change(s).")
    return 0


if __name__ == "__main__":
    sys.exit(main())