import io
from typing import List, Tuple, Dict, Any, Optional
from pptx import Presentation
from pptx.util import Inches, Pt
from pptx.enum.text import PP_ALIGN
from pptx.dml.color import RGBColor
from pptx.enum.shapes import MSO_AUTO_SHAPE_TYPE
from PIL import Image
import matplotlib.pyplot as plt


def _add_logo(prs: Presentation, slide, logo_bytes: Optional[bytes]):
    if not logo_bytes:
        return
    img = Image.open(io.BytesIO(logo_bytes)).convert("RGBA")
    # Resize to fit width<=2.0in, height<=1.0in
    max_w, max_h = Inches(2.0), Inches(1.0)
    w, h = img.size
    ratio = min(max_w / max(w, 1), max_h / max(h, 1))
    new_size = (max(1, int(w * ratio)), max(1, int(h * ratio)))
    resized = img.resize(new_size)
    b = io.BytesIO()
    resized.save(b, format="PNG")
    b.seek(0)
    # Place top-right with small margin
    left = prs.slide_width - max_w - Inches(0.5)
    top = Inches(0.2)
    slide.shapes.add_picture(b, left, top)


def _apply_theme_bg(slide, rgb):
    fill = slide.background.fill
    fill.solid()
    fill.fore_color.rgb = RGBColor(*rgb)


def _title_slide(prs, title_text: str, theme_rgb, logo_bytes):
    slide_layout = prs.slide_layouts[0]  # Title slide
    slide = prs.slides.add_slide(slide_layout)
    title = slide.shapes.title
    subtitle = slide.placeholders[1]
    title.text = title_text
    subtitle.text = "自動生成プレゼンテーション"
    # Accent band
    _apply_theme_bg(slide, theme_rgb)
    # White rounded rectangle for readability
    left = Inches(0.6)
    top = Inches(1.8)
    width = prs.slide_width - Inches(1.2)
    height = Inches(2.2)
    box = slide.shapes.add_shape(MSO_AUTO_SHAPE_TYPE.ROUNDED_RECTANGLE, left, top, width, height)
    box.fill.solid()
    box.fill.fore_color.rgb = RGBColor(255, 255, 255)
    box.line.color.rgb = RGBColor(0, 0, 0)
    box.line.transparency = 0.8
    # Reposition title
    title.left = left + Inches(0.3)
    title.top = top + Inches(0.3)
    title.width = width - Inches(0.6)
    title.height = Inches(1.4)
    for p in title.text_frame.paragraphs:
        p.font.size = Pt(40)
        p.font.bold = True
    # Subtitle
    subtitle.left = left + Inches(0.3)
    subtitle.top = top + Inches(1.6)
    subtitle.width = width - Inches(0.6)
    subtitle.height = Inches(0.8)
    for p in subtitle.text_frame.paragraphs:
        p.font.size = Pt(16)
        p.font.bold = False
    _add_logo(prs, slide, logo_bytes)


def _summary_slide(prs, summary: str):
    if not summary:
        return
    slide = prs.slides.add_slide(prs.slide_layouts[1])  # Title and Content
    slide.shapes.title.text = "エグゼクティブサマリー"
    tf = slide.placeholders[1].text_frame
    tf.clear()
    # Split summary into bullet-ish lines
    lines = [ln.strip() for ln in summary.splitlines() if ln.strip()]
    if not lines:
        lines = [summary]
    for i, ln in enumerate(lines):
        p = tf.add_paragraph() if i > 0 else tf.paragraphs[0]
        p.text = ln
        p.level = 0


def _section_slide(prs, title: str, bullets: List[str]):
    slide = prs.slides.add_slide(prs.slide_layouts[1])
    slide.shapes.title.text = title[:90]
    tf = slide.placeholders[1].text_frame
    tf.clear()
    if not bullets:
        bullets = ["(要点なし)"]
    for i, b in enumerate(bullets[:12]):
        p = tf.add_paragraph() if i > 0 else tf.paragraphs[0]
        p.text = b
        p.level = 0


def _table_slide(prs, title: str, pairs: List[tuple]):
    slide = prs.slides.add_slide(prs.slide_layouts[5])  # Title Only
    slide.shapes.title.text = title
    rows = len(pairs) + 1
    cols = 2
    left = Inches(0.5)
    top = Inches(1.8)
    width = prs.slide_width - Inches(1.0)
    height = prs.slide_height - Inches(2.6)
    table = slide.shapes.add_table(rows, cols, left, top, width, height).table
    table.cell(0, 0).text = "項目"
    table.cell(0, 1).text = "値"
    for r, (k, v) in enumerate(pairs, start=1):
        table.cell(r, 0).text = str(k)
        table.cell(r, 1).text = str(v)


def _chart_slide(prs, title: str, series: List[tuple]):
    slide = prs.slides.add_slide(prs.slide_layouts[5])  # Title Only
    slide.shapes.title.text = title
    # Build bar chart via matplotlib and embed as image
    labels = [x[0] for x in series]
    values = [x[1] for x in series]
    fig = plt.figure(figsize=(8, 4.5))
    plt.bar(range(len(values)), values)
    plt.xticks(range(len(labels)), labels, rotation=20, ha='right')
    plt.tight_layout()
    buf = io.BytesIO()
    fig.savefig(buf, format='png', dpi=200)
    plt.close(fig)
    buf.seek(0)
    left = Inches(0.5)
    top = Inches(1.6)
    width = prs.slide_width - Inches(1.0)
    height = prs.slide_height - Inches(2.2)
    slide.shapes.add_picture(buf, left, top, width=width, height=height)


def _add_footer(prs, theme_rgb):
    for idx, slide in enumerate(prs.slides, start=1):
        left = Inches(0.3)
        top = prs.slide_height - Inches(0.4)
        width = prs.slide_width - Inches(0.6)
        height = Inches(0.3)
        shp = slide.shapes.add_shape(MSO_AUTO_SHAPE_TYPE.RECTANGLE, left, top, width, height)
        shp.fill.solid()
        shp.fill.fore_color.rgb = RGBColor(*theme_rgb)
        shp.line.fill.background()
        # Slide number text box
        tx = slide.shapes.add_textbox(prs.slide_width - Inches(1.0), top - Inches(0.05), Inches(0.8), Inches(0.3))
        tf = tx.text_frame
        p = tf.paragraphs[0]
        p.text = f"{idx}"
        p.font.size = Pt(10)
        p.alignment = PP_ALIGN.RIGHT


def build_presentation(output_path: str,
                        title: str,
                        theme_rgb: tuple,
                        logo_bytes: Optional[bytes],
                        executive_summary: Optional[str],
                        sections: List[Tuple[str, str]],
                        bullets_by_section: Dict[int, List[str]],
                        tables: List[Dict[str, Any]],
                        charts: List[Dict[str, Any]]):
    prs = Presentation()

    # Title slide
    _title_slide(prs, title, theme_rgb, logo_bytes)

    # Summary
    _summary_slide(prs, executive_summary)

    # Sections
    for idx, (sec_title, _body) in enumerate(sections):
        bullets = bullets_by_section.get(idx, [])
        _section_slide(prs, sec_title, bullets)

    # Tables
    for tbl in tables:
        _table_slide(prs, tbl.get("title", "表"), tbl.get("pairs", []))

    # Charts
    for ch in charts:
        _chart_slide(prs, ch.get("title", "チャート"), ch.get("series", []))

    _add_footer(prs, theme_rgb)

    prs.save(output_path)