"""Configuration: sedona home lives in `system.properties` next to this file.

Same key sedonac itself uses, but written as a plain Windows path:

    sedona.home=C:\\path\\to\\sedona

We only *read* this file, so there is no reason to escape anything. Java's
Properties (what sedonac uses) treats `\\` as an escape, so its own files double
them up -- `\\\\path\\\\to`. Both parse here: `\\\\` collapses to `\\`, and every
other backslash is kept literally, so `C:\\niagara` does not turn into a newline.

If the key is missing, or the directory no longer holds `manifests/`, a folder
chooser is shown and the answer is written back to `system.properties`.
"""
import os, sys

HERE = os.path.dirname(os.path.abspath(__file__))
PROPS = os.path.join(HERE, "system.properties")
KEY = "sedona.home"


# ---------- .properties ----------
def _unescape(v):
    """Collapse `\\\\` to `\\`; leave any other backslash alone.

    Accepts both our plain paths and java-escaped ones, and never mistakes a
    path segment for an escape (`C:\\niagara` stays `C:\\niagara`).
    """
    out, i = [], 0
    while i < len(v):
        if v[i] == "\\" and i + 1 < len(v) and v[i + 1] == "\\":
            i += 1
        out.append(v[i])
        i += 1
    return "".join(out)


def read_props(path=PROPS):
    props = {}
    if not os.path.exists(path):
        return props
    with open(path, "r", encoding="utf-8", errors="replace") as f:
        for line in f:
            line = line.strip()
            if not line or line[0] in "#!" or "=" not in line:
                continue
            k, v = line.split("=", 1)
            props[k.strip()] = _unescape(v.strip())   # last wins
    return props


def write_prop(key, value, path=PROPS):
    """Set `key`, keeping every other line of the file intact."""
    lines = []
    if os.path.exists(path):
        with open(path, "r", encoding="utf-8", errors="replace") as f:
            lines = f.read().splitlines()

    new = "%s=%s" % (key, value)
    done = False
    for i, line in enumerate(lines):
        s = line.strip()
        if s and s[0] not in "#!" and "=" in s and s.split("=", 1)[0].strip() == key:
            lines[i] = new if not done else "#" + line   # comment out later dupes
            done = True
    if not done:
        lines.append(new)

    with open(path, "w", encoding="utf-8") as f:
        f.write("\n".join(lines) + "\n")


# ---------- dialogs ----------
def _tk():
    """A hidden root window, or None when no GUI is available."""
    try:
        import tkinter as tk
        root = tk.Tk()
        root.withdraw()
        return root
    except Exception:
        return None


def ask_directory(title, initial=None):
    root = _tk()
    if root is None:
        return None
    try:
        from tkinter import filedialog
        return filedialog.askdirectory(title=title, initialdir=initial or HERE) or None
    finally:
        root.destroy()


def ask_open_file(title, filetypes, initial=None):
    root = _tk()
    if root is None:
        return None
    try:
        from tkinter import filedialog
        return filedialog.askopenfilename(title=title, filetypes=filetypes,
                                          initialdir=initial or HERE) or None
    finally:
        root.destroy()


def ask_save_file(title, filetypes, defaultextension, initialfile=None, initial=None):
    root = _tk()
    if root is None:
        return None
    try:
        from tkinter import filedialog
        return filedialog.asksaveasfilename(title=title, filetypes=filetypes,
                                            defaultextension=defaultextension,
                                            initialfile=initialfile,
                                            initialdir=initial or HERE) or None
    finally:
        root.destroy()


# ---------- api ----------
def is_sedona_home(path):
    return bool(path) and os.path.isdir(os.path.join(path, "manifests"))


def get_sedona_home(interactive=True):
    """Path from system.properties, prompting (and saving) when unusable."""
    home = read_props().get(KEY)
    if is_sedona_home(home):
        return home

    if not interactive:
        raise SystemExit("%s not set (or has no manifests/) in %s" % (KEY, PROPS))

    why = "not set in" if not home else "invalid (%s), update" % home
    print("sedona.home %s %s -- please choose the sedona installation folder" % (why, PROPS))
    while True:
        picked = ask_directory("Select Sedona home (the folder containing manifests/)",
                               home if home and os.path.isdir(home) else None)
        if not picked:
            raise SystemExit("no sedona home selected")
        picked = os.path.normpath(picked)
        if is_sedona_home(picked):
            write_prop(KEY, picked)
            print("saved %s=%s to %s" % (KEY, picked, PROPS))
            return picked
        print("  %s has no manifests/ subfolder -- try again" % picked)


SAX = ("Sedona app XML", "*.sax")
SAB = ("Sedona app binary", "*.sab")
ANY = ("All files", "*.*")


def choose_input_file(initial=None):
    """Pick the file to convert -- direction follows its extension."""
    return ask_open_file("Select the .sax or .sab application file to convert",
                         [("Sedona app (*.sax, *.sab)", "*.sax *.sab"), SAX, SAB, ANY],
                         initial)


def choose_sax_file(initial=None):
    return ask_open_file("Select the .sax application file", [SAX, ANY], initial)


def choose_sab_file(initialfile=None, initial=None):
    """Save-as for the .sab produced from a .sax."""
    return ask_save_file("Save the .sab application file", [SAB, ANY],
                         ".sab", initialfile, initial)


def choose_sax_output(initialfile=None, initial=None):
    """Save-as for the .sax produced from a .sab."""
    return ask_save_file("Save the .sax application file", [SAX, ANY],
                         ".sax", initialfile, initial)


if __name__ == "__main__":
    print(get_sedona_home())