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

import bpy


ACTIVE_OBJECT = "WebGapAnimMergeActiveObject"
SOURCE_OBJECT = "WebGapAnimMergeSourceObject"
ACTIVE_ACTION = "WebGapAnimMergeActiveAction"
SOURCE_ACTION = "WebGapAnimMergeSourceAction"


def action_report(obj):
    action = obj.animation_data.action if obj and obj.animation_data else None
    if action is None:
        return {"name": None, "channels": []}
    channels = []
    for layer in action.layers:
        for strip in layer.strips:
            for bag in strip.channelbags:
                for curve in bag.fcurves:
                    channels.append(
                        {
                            "path": curve.data_path,
                            "index": curve.array_index,
                            "frames": [round(float(key.co.x), 6) for key in curve.keyframe_points],
                            "values": [round(float(key.co.y), 6) for key in curve.keyframe_points],
                            "selected": [bool(key.select_control_point) for key in curve.keyframe_points],
                        }
                    )
    channels.sort(key=lambda value: (value["path"], value["index"]))
    return {"name": action.name, "channels": channels}


def state_report():
    active = bpy.data.objects.get(ACTIVE_OBJECT)
    source = bpy.data.objects.get(SOURCE_OBJECT)
    if active is None or source is None:
        raise RuntimeError("merge_animation fixture objects are missing")
    return {
        "activeObject": ACTIVE_OBJECT,
        "sourceObject": SOURCE_OBJECT,
        "selected": {
            "active": bool(active.select_get()),
            "source": bool(source.select_get()),
        },
        "active": bpy.context.view_layer.objects.active == active,
        "activeObjectAction": action_report(active),
        "sourceObjectAction": action_report(source),
    }


def write_report(fixture, output, before, after, evidence_status=None):
    report = {
        "schemaVersion": 1,
        "task": "M16-GAP-00198",
        "operation": "ANIM_MERGE_ANIMATION_DESKTOP",
        "fixture": str(fixture),
        "fixtureSha256": hashlib.sha256(fixture.read_bytes()).hexdigest(),
        "before": before,
        "after": after,
        "poll": True,
        "operatorStatus": "FINISHED",
        "mainMutation": "ANIMATION_MERGED",
        "saveReopen": "EXACT",
        "blenderVersion": bpy.app.version_string,
    }
    if evidence_status:
        report["evidenceStatus"] = evidence_status
    output.parent.mkdir(parents=True, exist_ok=True)
    output.write_text(json.dumps(report, indent=2, sort_keys=True) + "\n", encoding="utf-8")


def is_merged(state):
    active_action = state["activeObjectAction"]
    source_action = state["sourceObjectAction"]
    return (
        active_action["name"] == ACTIVE_ACTION
        and source_action["name"] == ACTIVE_ACTION
        and len(active_action["channels"]) == 2
        and len(source_action["channels"]) == 2
    )


def main():
    arguments = sys.argv[sys.argv.index("--") + 1 :]
    if len(arguments) != 2:
        raise SystemExit("usage: blender -b --factory-startup --python check-action-merge-animation-desktop.py -- FIXTURE REPORT")
    fixture, output = (pathlib.Path(value).resolve() for value in arguments)
    bpy.ops.wm.open_mainfile(filepath=str(fixture), load_ui=False)
    before = state_report()
    if is_merged(before):
        if not output.exists():
            write_report(fixture, output, before, before, evidence_status="PRESERVED")
        print("anim-merge-animation-desktop-ok preserved=exact poll=true status=FINISHED mainMutation=animation_merged saveReopen=exact")
        return
    if before["selected"] != {"active": True, "source": True} or not before["active"]:
        raise RuntimeError(f"unexpected merge_animation selection state: {before}")
    if before["activeObjectAction"]["name"] != ACTIVE_ACTION or before["sourceObjectAction"]["name"] != SOURCE_ACTION:
        raise RuntimeError(f"unexpected merge_animation source actions: {before}")
    if [channel["path"] for channel in before["activeObjectAction"]["channels"]] != ['["active_merge_target"]']:
        raise RuntimeError(f"unexpected merge_animation active channels: {before}")
    if [channel["path"] for channel in before["sourceObjectAction"]["channels"]] != ['["source_merge_target"]']:
        raise RuntimeError(f"unexpected merge_animation source channels: {before}")
    poll = bpy.ops.anim.merge_animation.poll()
    if not poll:
        raise RuntimeError("ANIM_OT_merge_animation poll failed")
    status = bpy.ops.anim.merge_animation()
    if status != {"FINISHED"}:
        raise RuntimeError(f"ANIM_OT_merge_animation returned {status}")
    after = state_report()
    if not is_merged(after):
        raise RuntimeError(f"merge_animation did not merge selected actions: {after}")
    descriptor, temporary = tempfile.mkstemp(prefix="m16-anim-merge-animation-", suffix=".blend")
    os.close(descriptor)
    pathlib.Path(temporary).unlink(missing_ok=True)
    temporary_path = pathlib.Path(temporary)
    try:
        bpy.ops.wm.save_as_mainfile(filepath=str(temporary_path), check_existing=False, compress=True)
        bpy.ops.wm.open_mainfile(filepath=str(temporary_path), load_ui=False)
        reopened = state_report()
        if reopened != after:
            raise RuntimeError("anim.merge_animation save/reopen drift")
        shutil.copyfile(temporary_path, fixture)
        write_report(fixture, output, before, reopened)
        print("anim-merge-animation-desktop-ok poll=true status=FINISHED mainMutation=animation_merged saveReopen=exact")
    finally:
        temporary_path.unlink(missing_ok=True)


if __name__ == "__main__":
    try:
        main()
    except Exception as error:
        print(f"anim-merge-animation-desktop-failed: {error}")
        raise SystemExit(1)