"""FCPXMLWriter: gera um documento novo a partir de objetos Python.

Extraído de writer.py — ver fcpxml/writer/__init__.py para o conjunto.
"""

import uuid
import xml.etree.ElementTree as ET
from datetime import datetime

from ..models import (
    Marker,
    Project,
    Timecode,
)
from .document import write_fcpxml
from .helpers import build_marker_element

# ============================================================================
# FCPXML GENERATOR - Create from Python objects
# ============================================================================

class FCPXMLWriter:
    """Generate a new FCPXML document from Python dataclass objects.

    Converts a ``Project`` (containing ``Timeline`` → ``Clip`` → ``Marker``
    hierarchies) into a spec-compliant FCPXML v1.11 element tree and writes
    it to disk.  Used by ``RoughCutGenerator`` and the ``generate_*`` MCP
    tools to create fresh timelines from scratch.

    Unlike ``FCPXMLModifier`` (which mutates existing XML), this class
    *creates* XML from structured Python objects.

    Example::

        from fcpxml.models import Project, Timeline, Clip, Timecode
        project = Project(name="My Edit", timelines=[...])
        writer = FCPXMLWriter()
        writer.write_project(project, "output.fcpxml")
    """

    def __init__(self, version: str = "1.13"):
        """Initialize writer targeting the given FCPXML version."""
        self.version = version
        self.resource_counter = 1

    def _next_resource_id(self) -> str:
        """Return an auto-incrementing resource ID (r1, r2, ...)."""
        rid = f"r{self.resource_counter}"
        self.resource_counter += 1
        return rid

    def _generate_uid(self) -> str:
        """Generate a unique identifier for FCPXML elements."""
        return str(uuid.uuid4()).upper()

    def _tc_to_rational(self, tc: Timecode) -> str:
        """Convert a Timecode to FCPXML rational time string (e.g. '48/24s')."""
        return f"{tc.frames}/{int(tc.frame_rate)}s"

    def write_project(self, project: Project, filepath: str):
        """Write a project to an FCPXML file."""
        root = self._build_fcpxml(project)
        write_fcpxml(root, filepath)

    def _build_fcpxml(self, project: Project) -> ET.Element:
        """Build the full FCPXML element tree: fcpxml > resources + library > event > project."""
        root = ET.Element('fcpxml', version=self.version)
        resources = ET.SubElement(root, 'resources')
        resource_map = {}

        if project.timelines:
            timeline = project.timelines[0]
            format_id = self._next_resource_id()
            ET.SubElement(resources, 'format',
                id=format_id,
                name=f"FFVideoFormat{timeline.height}p{int(timeline.frame_rate)}",
                frameDuration=f"1/{int(timeline.frame_rate)}s",
                width=str(timeline.width), height=str(timeline.height))
            resource_map['_format'] = format_id

        library = ET.SubElement(root, 'library',
            location=f"file:///Users/editor/Movies/{project.name}.fcpbundle/")
        event = ET.SubElement(library, 'event', name=project.name, uid=self._generate_uid())

        for timeline in project.timelines:
            self._add_timeline(event, timeline, resources, resource_map)
        return root

    def _add_timeline(self, event, timeline, resources, resource_map):
        """Add a timeline as a project > sequence > spine structure under the event."""
        project_elem = ET.SubElement(event, 'project',
            name=timeline.name, uid=self._generate_uid(),
            modDate=datetime.now().strftime("%Y-%m-%d %H:%M:%S -0500"))

        format_id = resource_map.get('_format', 'r1')
        sequence = ET.SubElement(project_elem, 'sequence',
            format=format_id, duration=self._tc_to_rational(timeline.duration),
            tcStart="0s", tcFormat="NDF", audioLayout="stereo", audioRate="48k")

        spine = ET.SubElement(sequence, 'spine')
        for clip in timeline.clips:
            self._add_clip(spine, clip, resources, resource_map)
        for marker in timeline.markers:
            self._add_marker(sequence, marker)

    def _add_clip(self, spine, clip, resources, resource_map):
        """Add a clip as an asset-clip element, creating its asset resource if needed."""
        if clip.media_path and clip.media_path not in resource_map:
            asset_id = self._next_resource_id()
            ET.SubElement(resources, 'asset', id=asset_id, name=clip.name,
                uid=self._generate_uid(), src=clip.media_path, start="0s",
                duration=self._tc_to_rational(clip.duration), hasVideo="1", hasAudio="1")
            resource_map[clip.media_path] = asset_id

        asset_id = resource_map.get(clip.media_path, 'r1')
        format_id = resource_map.get('_format', 'r1')
        clip_elem = ET.SubElement(spine, 'asset-clip',
            ref=asset_id, offset=self._tc_to_rational(clip.start), name=clip.name,
            start=self._tc_to_rational(clip.source_start) if clip.source_start else "0s",
            duration=self._tc_to_rational(clip.duration), format=format_id, tcFormat="NDF")

        for marker in clip.markers:
            self._add_marker(clip_elem, marker)
        for keyword in clip.keywords:
            self._add_keyword(clip_elem, keyword)

    def _add_marker(self, parent: ET.Element, marker: Marker):
        """Add a marker or chapter-marker element to a parent clip or sequence."""
        build_marker_element(
            parent=parent,
            marker_type=marker.marker_type,
            start=self._tc_to_rational(marker.start),
            duration=self._tc_to_rational(marker.duration) if marker.duration else "1/24s",
            name=marker.name,
            note=marker.note or None,
        )

    def _add_keyword(self, parent, keyword):
        """Add a keyword element with optional start/duration range to a parent clip."""
        attrs = {'value': keyword.value}
        if keyword.start:
            attrs['start'] = self._tc_to_rational(keyword.start)
        if keyword.duration:
            attrs['duration'] = self._tc_to_rational(keyword.duration)
        ET.SubElement(parent, 'keyword', **attrs)