#!/usr/bin/env python3
import hashlib
import json
import os
import pathlib
import sys
import tempfile

import bpy


def action_view_report():
    screen = None
    area = None
    for candidate_screen in bpy.data.screens:
        candidate_area = next(
            (candidate for candidate in candidate_screen.areas
             if candidate.type == "DOPESHEET_EDITOR" and candidate.spaces.active.ui_mode == "ACTION"),
            None,
        )
        if candidate_area is not None:
            screen, area = candidate_screen, candidate_area
            break
    if area is None:
        raise RuntimeError("Action Editor area is missing")
    region = next((candidate for candidate in area.regions if candidate.type == "WINDOW"), None)
    if region is None:
        raise RuntimeError("Action Editor window region is missing")
    view = region.view2d
    xmin, ymin = view.region_to_view(0, 0)
    xmax, ymax = view.region_to_view(region.width - 1, region.height - 1)
    return {
        "areaType": area.type,
        "uiMode": area.spaces.active.ui_mode,
        "currentFrame": int(bpy.context.scene.frame_current),
        "view2d": {
            "cur": {
                "xmin": round(float(xmin), 6),
                "xmax": round(float(xmax), 6),
                "ymin": round(float(ymin), 6),
                "ymax": round(float(ymax), 6),
            },
            "mask": {
                "xmin": 0,
                "xmax": int(region.width - 1),
                "ymin": 0,
                "ymax": int(region.height - 1),
            },
        },
    }


def main():
    arguments = sys.argv[sys.argv.index("--") + 1 :]
    if len(arguments) != 2:
        raise SystemExit("usage: blender -b --python check-action-view-frame-desktop.py -- FIXTURE REPORT")
    fixture, output = (pathlib.Path(value).resolve() for value in arguments)
    bpy.ops.wm.open_mainfile(filepath=str(fixture), load_ui=True)
    before = action_view_report()
    if before["currentFrame"] != 3:
        raise RuntimeError(f"unexpected current frame: {before}")
    descriptor, temporary = tempfile.mkstemp(prefix="m16-action-view-frame-reopen-", suffix=".blend")
    os.close(descriptor)
    try:
        bpy.ops.wm.save_as_mainfile(filepath=temporary, check_existing=False, compress=True)
        bpy.ops.wm.open_mainfile(filepath=temporary, load_ui=True)
        after = action_view_report()
    finally:
        pathlib.Path(temporary).unlink(missing_ok=True)
    if before != after:
        raise RuntimeError(f"action.view_frame save/reopen drift: {before} != {after}")
    report = {
        "schemaVersion": 1,
        "task": "M16-GAP-00148",
        "operation": "ACTION_VIEW_FRAME_DESKTOP",
        "fixture": str(fixture),
        "fixtureSha256": hashlib.sha256(fixture.read_bytes()).hexdigest(),
        "action": after,
        "saveReopen": "EXACT",
        "blenderVersion": bpy.app.version_string,
    }
    output.parent.mkdir(parents=True, exist_ok=True)
    output.write_text(json.dumps(report, indent=2, sort_keys=True) + "\n", encoding="utf-8")
    print(
        "action-view-frame-desktop-ok area=DOPESHEET_EDITOR mode=ACTION currentFrame=3 "
        "saveReopen=exact"
    )


if __name__ == "__main__":
    main()