"""
pipeline.py — orchestrates the full ingestion flow for a single PDF.
Calls detector → chunker → summarizer → mem0_writer → manifest in order.
"""

from __future__ import annotations

import logging
import shutil
from pathlib import Path

from rich.console import Console
from rich.progress import Progress, SpinnerColumn, TextColumn, BarColumn, TaskProgressColumn

from .config import cfg
from .detector import detect_structure, DocumentStructure
from .chunker import chunk_section
from .summarizer import summarize_book, summarize_chapter, summarize_flat_document
from .mem0_writer import (
    write_book_summary,
    write_chapter_summary,
    write_content_chunks_batch,
)
from .manifest import compute_file_hash, already_ingested, build_manifest, save_manifest

log = logging.getLogger(__name__)
console = Console()


def ingest(pdf_path: str | Path) -> bool:
    """
    Full ingestion pipeline for a single PDF.
    Moves file through inbox → processing → done.
    Returns True on success, False on failure.
    """
    pdf_path = Path(pdf_path)
    processing_path = Path(cfg.books_processing) / pdf_path.name
    done_path = Path(cfg.books_done) / pdf_path.name

    # ── Deduplication check ──────────────────────────────────────────────────
    console.print(f"\n[bold cyan]📚 Ingesting:[/] {pdf_path.name}")
    file_hash = compute_file_hash(pdf_path)

    if already_ingested(file_hash):
        console.print("[yellow]⚠ Already ingested (hash match). Skipping.[/]")
        return True

    # ── Move to processing ───────────────────────────────────────────────────
    Path(cfg.books_processing).mkdir(parents=True, exist_ok=True)
    shutil.move(str(pdf_path), processing_path)
    log.info("Moved to processing: %s", processing_path)

    try:
        result = _run_pipeline(processing_path, file_hash)
    except Exception as e:
        log.exception("Pipeline failed for %s: %s", pdf_path.name, e)
        console.print(f"[red]✗ Pipeline failed: {e}[/]")
        # Move back to inbox so user can retry
        shutil.move(str(processing_path), pdf_path)
        return False

    # ── Archive ──────────────────────────────────────────────────────────────
    Path(cfg.books_done).mkdir(parents=True, exist_ok=True)
    shutil.move(str(processing_path), done_path)
    log.info("Archived to done: %s", done_path)

    return result


def _run_pipeline(pdf_path: Path, file_hash: str) -> bool:
    """Inner pipeline — assumes file is already in processing/."""

    with Progress(
        SpinnerColumn(),
        TextColumn("[progress.description]{task.description}"),
        BarColumn(),
        TaskProgressColumn(),
        console=console,
        transient=True,
    ) as progress:

        # ── Step 1: Detect structure ─────────────────────────────────────────
        task = progress.add_task("Detecting structure...", total=None)
        structure = detect_structure(pdf_path)
        progress.update(task, completed=True)

        console.print(
            f"  [green]✓[/] [bold]{structure.doc_type.upper()}[/] document — "
            f"[dim]{structure.title}[/]"
        )
        if structure.doc_type == "structured":
            console.print(f"  [green]✓[/] {len(structure.sections)} sections detected")

        # ── Route to appropriate sub-pipeline ───────────────────────────────
        if structure.doc_type == "structured":
            return _structured_pipeline(pdf_path, structure, file_hash, progress)
        else:
            return _flat_pipeline(pdf_path, structure, file_hash, progress)


def _structured_pipeline(
    pdf_path: Path,
    structure: DocumentStructure,
    file_hash: str,
    progress: Progress,
) -> bool:

    chapter_summary_ids: list[str] = []
    chapter_summaries: list[str] = []
    all_content_ids: list[str] = []

    # ── Step 2: Summarize chapters ───────────────────────────────────────────
    task = progress.add_task("Summarizing chapters...", total=len(structure.sections))

    for section in structure.sections:
        summary = summarize_chapter(
            book_title=structure.title,
            chapter_title=section.title,
            chapter_text=section.raw_text,
        )
        chapter_summaries.append(summary)

        mem_id = write_chapter_summary(
            title=structure.title,
            chapter_title=section.title,
            chapter_number=section.chapter_number,
            summary=summary,
            source_file=structure.source_file,
            page_start=section.page_start,
            page_end=section.page_end,
        )
        if mem_id:
            chapter_summary_ids.append(mem_id)

        progress.advance(task)

    # ── Step 3: Book-level summary ───────────────────────────────────────────
    task2 = progress.add_task("Generating book summary...", total=None)
    book_summary = summarize_book(structure.title, chapter_summaries)
    book_summary_id = write_book_summary(
        title=structure.title,
        summary=book_summary,
        source_file=structure.source_file,
    )
    progress.update(task2, completed=True)

    # ── Step 4: Chunk and store content ─────────────────────────────────────
    task3 = progress.add_task("Chunking content...", total=len(structure.sections))

    for section in structure.sections:
        chunks = chunk_section(
            text=section.raw_text,
            source_file=structure.source_file,
            section_title=section.title,
            chapter_number=section.chapter_number,
            page_start=section.page_start,
            page_end=section.page_end,
        )
        ids = write_content_chunks_batch(chunks, doc_title=structure.title)
        all_content_ids.extend(ids)
        progress.advance(task3)

    # ── Step 5: Save manifest ────────────────────────────────────────────────
    manifest = build_manifest(
        source_file=structure.source_file,
        file_hash=file_hash,
        doc_type="structured",
        doc_title=structure.title,
        chapters_detected=len(structure.sections),
        book_summary_id=book_summary_id,
        chapter_summary_ids=chapter_summary_ids,
        content_ids=all_content_ids,
    )
    save_manifest(manifest)

    _print_summary(manifest.memories, structure.title)
    return True


def _flat_pipeline(
    pdf_path: Path,
    structure: DocumentStructure,
    file_hash: str,
    progress: Progress,
) -> bool:

    # ── Step 2: Summarize whole doc ──────────────────────────────────────────
    task = progress.add_task("Summarizing document...", total=None)
    doc_summary = summarize_flat_document(structure.title, structure.full_text)
    book_summary_id = write_book_summary(
        title=structure.title,
        summary=doc_summary,
        source_file=structure.source_file,
    )
    progress.update(task, completed=True)

    # ── Step 3: Chunk and store content ─────────────────────────────────────
    task2 = progress.add_task("Chunking content...", total=None)
    chunks = chunk_section(
        text=structure.full_text,
        source_file=structure.source_file,
    )
    content_ids = write_content_chunks_batch(chunks, doc_title=structure.title)
    progress.update(task2, completed=True)

    # ── Step 4: Save manifest ────────────────────────────────────────────────
    manifest = build_manifest(
        source_file=structure.source_file,
        file_hash=file_hash,
        doc_type="flat",
        doc_title=structure.title,
        chapters_detected=0,
        book_summary_id=book_summary_id,
        chapter_summary_ids=[],
        content_ids=content_ids,
    )
    save_manifest(manifest)

    _print_summary(manifest.memories, structure.title)
    return True


def _print_summary(memories: dict, title: str) -> None:
    total = sum(memories.values())
    console.print(
        f"\n[bold green]✓ Done![/] [dim]{title}[/]\n"
        f"  Memories stored: "
        f"[cyan]{memories.get('book_summary', 0)}[/] book · "
        f"[cyan]{memories.get('chapter_summary', 0)}[/] chapters · "
        f"[cyan]{memories.get('content', 0)}[/] chunks · "
        f"[bold]{total}[/] total\n"
    )