Format `mysqldump` sql file into editable style.

sqlfmt.py

#!/usr/bin/env python3
# coding: utf-8
"""
Author       : weaming
Created Time : 2019-04-18 15:18:31
"""
import sys
import argparse


class TextState:
    last_2_state = None
    last_1_state = None
    state = None
    levels = []  # (), ", ', `
    wrap = False

    def need_wrap(self):
        rv = False
        if self.wrap:
            self.wrap = False
            return True

        if self.is_escaped():
            return False

        self.wrap = False
        return rv

    def forward(self, char):
        self.last_2_state = self.last_1_state
        self.last_1_state = self.state
        self.state = char

        if not self.is_escaped():
            l12 = f"{self.last_1_state}{self.state}"

            if char == "(" and self.level(-1) not in ["--", "/*"]:
                self.levels.append("()")
                if self.level(-2) == "()":
                    return char
                else:
                    return "\n" + char

            if not self.levels:
                if l12 == "--":
                    self.levels.append("--")
                elif l12 == "/*":
                    self.levels.append("/*")
                elif char == "`":
                    self.levels.append("`")
            else:
                ll = self.levels[-1]
                if ll == "()":
                    if char == '"':
                        self.levels.append('"')
                    elif char == "'":
                        self.levels.append("'")

                for last, current in [
                    ("()", ")"),
                    ('"', '"'),
                    ("'", "'"),
                    ("`", "`"),
                    ("--", "\n"),
                    ("/*", "*/"),
                ]:
                    if ll == last and (char == current or l12 == current):
                        self.levels and self.levels.pop()
                        break

        if self.need_wrap():
            return char + "\n"
        else:
            return char

    def level(self, n):
        try:
            return self.levels[n]
        except IndexError:
            return None

    def is_escaped(self):
        return (
            self.level(-1) != "--"
            and self.last_2_state != "\\"
            and self.last_1_state == "\\"
        )


def main(args):
    with open(args.file) as f:
        text = f.read()
    sm = TextState()
    with open(args.out, "w") as out:
        for c in text:
            v = sm.forward(c)
            out.write(v)


if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument("file")
    parser.add_argument("-o", "--out", default="/dev/stdout")
    args = parser.parse_args()

    main(args)