"""
Reassign speakers in a transcript
=================================

"""

from typing import Annotated, Optional

from fastapi import APIRouter, Depends, HTTPException
from pydantic import BaseModel, Field

import reflector.auth as auth
from reflector.db.transcripts import transcripts_controller

router = APIRouter()


class SpeakerAssignment(BaseModel):
    speaker: Optional[int] = Field(None, ge=0)
    participant: Optional[str] = Field(None)
    timestamp_from: float
    timestamp_to: float


class SpeakerAssignmentStatus(BaseModel):
    status: str


class SpeakerMerge(BaseModel):
    speaker_from: int
    speaker_to: int


@router.patch("/transcripts/{transcript_id}/speaker/assign")
async def transcript_assign_speaker(
    transcript_id: str,
    assignment: SpeakerAssignment,
    user: Annotated[auth.UserInfo, Depends(auth.current_user)],
) -> SpeakerAssignmentStatus:
    user_id = user["sub"]
    transcript = await transcripts_controller.get_by_id_for_http(
        transcript_id, user_id=user_id
    )
    if transcript.user_id is not None and transcript.user_id != user_id:
        raise HTTPException(status_code=403, detail="Not authorized")

    if not transcript:
        raise HTTPException(status_code=404, detail="Transcript not found")

    if assignment.speaker is None and assignment.participant is None:
        raise HTTPException(
            status_code=400,
            detail="Either speaker or participant must be provided",
        )

    if assignment.speaker is not None and assignment.participant is not None:
        raise HTTPException(
            status_code=400,
            detail="Only one of speaker or participant must be provided",
        )

    # if it's a participant, search for it
    if assignment.speaker is not None:
        speaker = assignment.speaker

    elif assignment.participant is not None:
        participant = next(
            (
                participant
                for participant in transcript.participants
                if participant.id == assignment.participant
            ),
            None,
        )
        if not participant:
            raise HTTPException(
                status_code=404,
                detail="Participant not found",
            )

        # if the participant does not have a speaker, create one
        if participant.speaker is None:
            participant.speaker = transcript.find_empty_speaker()
            await transcripts_controller.upsert_participant(transcript, participant)

        speaker = participant.speaker

    # reassign speakers from words in the transcript
    ts_from = assignment.timestamp_from
    ts_to = assignment.timestamp_to
    changed_topics = []
    for topic in transcript.topics:
        changed = False
        for word in topic.words:
            if ts_from <= word.start <= ts_to:
                word.speaker = speaker
                changed = True
        if changed:
            changed_topics.append(topic)

    # batch changes
    for topic in changed_topics:
        transcript.upsert_topic(topic)
    await transcripts_controller.update(
        transcript,
        {
            "topics": transcript.topics_dump(),
        },
    )

    return SpeakerAssignmentStatus(status="ok")


@router.patch("/transcripts/{transcript_id}/speaker/merge")
async def transcript_merge_speaker(
    transcript_id: str,
    merge: SpeakerMerge,
    user: Annotated[auth.UserInfo, Depends(auth.current_user)],
) -> SpeakerAssignmentStatus:
    user_id = user["sub"]
    transcript = await transcripts_controller.get_by_id_for_http(
        transcript_id, user_id=user_id
    )
    if transcript.user_id is not None and transcript.user_id != user_id:
        raise HTTPException(status_code=403, detail="Not authorized")

    if not transcript:
        raise HTTPException(status_code=404, detail="Transcript not found")

    # ensure both speaker are not assigned to the 2 differents participants
    participant_from = next(
        (
            participant
            for participant in transcript.participants
            if participant.speaker == merge.speaker_from
        ),
        None,
    )
    participant_to = next(
        (
            participant
            for participant in transcript.participants
            if participant.speaker == merge.speaker_to
        ),
        None,
    )
    if participant_from and participant_to:
        raise HTTPException(
            status_code=400,
            detail="Both speakers are assigned to participants",
        )

    # reassign speakers from words in the transcript
    speaker_from = merge.speaker_from
    speaker_to = merge.speaker_to
    changed_topics = []
    for topic in transcript.topics:
        changed = False
        for word in topic.words:
            if word.speaker == speaker_from:
                word.speaker = speaker_to
                changed = True
        if changed:
            changed_topics.append(topic)

    # batch changes
    for topic in changed_topics:
        transcript.upsert_topic(topic)
    await transcripts_controller.update(
        transcript,
        {
            "topics": transcript.topics_dump(),
        },
    )

    return SpeakerAssignmentStatus(status="ok")