import os
import gradio as gr
import rag_engine as rag

print("Loading RAG engine...")
RETRIEVER = rag.build_retriever()
print(f"Loaded {len(RETRIEVER['texts'])} FAQ entries.")

API_KEY = os.environ.get("OPENROUTER_API_KEY", "")
DEFAULT_ACCENT = "#667eea"
DEFAULT_BOT_NAME = "FlowBar Support"
DEFAULT_TAGLINE = "Ask me anything about FlowBar -- account setup, features, billing, or troubleshooting."

PRESET_COLORS = [
    ("Violet", "#667eea"),
    ("Teal", "#0d9488"),
    ("Blue", "#3b82f6"),
    ("Green", "#22c55e"),
    ("Orange", "#f97316"),
    ("Pink", "#ec4899"),
    ("Red", "#ef4444"),
    ("Gold", "#eab308"),
    ("Gray", "#6b7280"),
]


def respond(message, history):
    if not message.strip():
        return "Please enter a question."
    results = rag.search(RETRIEVER, message, top_k=3)
    if not results:
        return "I could not find relevant info. Try rephrasing."
    if API_KEY:
        text, _ = rag.generate_response(message, results, API_KEY)
    else:
        text, _ = rag.generate_response_light(message, results)
    return text


def _is_dark_color(hex_color):
    """Returns True if accent is dark (text needs to be white for contrast)."""
    hex_color = hex_color.lstrip("#")
    r, g, b = int(hex_color[0:2], 16), int(hex_color[2:4], 16), int(hex_color[4:6], 16)
    luminance = (0.299 * r + 0.587 * g + 0.114 * b) / 255
    return luminance < 0.5


def make_custom_css(accent):
    """Return full CSS with accent color applied to visible elements."""
    text_color = "#ffffff" if _is_dark_color(accent) else "#1a1a2e"
    # Gradio 5.20 wraps every CSS rule with high-specificity container prefix,
    # so we duplicate each rule with the same prefix to match specificity.
    # With equal specificity, the later rule (our dynamic injection) wins.
    p = ".gradio-container.gradio-container-5-20-0 .contain"
    return f"""
.gradio-container {{ max-width: 800px !important; margin: 0 auto; min-height: 600px; }}
.bot-row {{ background: #2d2d3d !important; }}
{p} .bot-row {{ background: #2d2d3d !important; }}
footer {{ display: none !important; }}
{p} footer {{ display: none !important; }}
/* --- Accent: header text --- */
h1 {{ color: {accent} !important; text-align: center; margin-bottom: 4px; }}
{p} h1 {{ color: {accent} !important; text-align: center; margin-bottom: 4px; }}
/* --- Accent: send button --- */
.submit-button, button.primary {{
    background: {accent} !important;
    border-color: {accent} !important;
    color: {text_color} !important;
}}
{p} .submit-button, {p} button.primary {{
    background: {accent} !important;
    border-color: {accent} !important;
    color: {text_color} !important;
}}
.submit-button:hover, button.primary:hover {{
    filter: brightness(1.15) !important;
}}
{p} .submit-button:hover, {p} button.primary:hover {{
    filter: brightness(1.15) !important;
}}
/* --- Accent: example buttons --- */
button.example {{
    border-color: {accent}66 !important;
    color: {accent} !important;
}}
{p} button.example {{
    border-color: {accent}66 !important;
    color: {accent} !important;
}}
button.example:hover {{
    background: {accent}22 !important;
    border-color: {accent} !important;
}}
{p} button.example:hover {{
    background: {accent}22 !important;
    border-color: {accent} !important;
}}
/* --- Accent: user chat bubbles --- */
.user-row {{
    background: {accent} !important;
    color: {text_color} !important;
    border-radius: 18px 18px 4px 18px !important;
}}
{p} .user-row {{
    background: {accent} !important;
    color: {text_color} !important;
    border-radius: 18px 18px 4px 18px !important;
}}
/* --- Accent: accordion toggle text --- */
.label-wrap {{
    color: {accent} !important;
}}
{p} .label-wrap {{
    color: {accent} !important;
}}
/* --- Accent: accordion open state --- */
.label-wrap.open {{
    border-color: {accent} !important;
}}
{p} .label-wrap.open {{
    border-color: {accent} !important;
}}
"""


def make_header(name, tagline, accent):
    return f"""
<div style="text-align:center;border-bottom:3px solid {accent};padding-bottom:12px;margin-bottom:4px;">
    <h1 style="color:{accent};margin-bottom:2px;">{name}</h1>
    <p style="color:#aaaaaa;margin-top:4px;">{tagline}</p>
</div>
"""


def update_all(name, tagline, accent):
    h = make_header(name, tagline, accent)
    css = f"<style>{make_custom_css(accent)}</style>"
    return h, css


with gr.Blocks(
    css=make_custom_css(DEFAULT_ACCENT),
    theme=gr.themes.Soft(primary_hue="violet", neutral_hue="slate"),
) as demo:
    header = gr.HTML(make_header(DEFAULT_BOT_NAME, DEFAULT_TAGLINE, DEFAULT_ACCENT))
    css_holder = gr.HTML("")

    chatbot = gr.ChatInterface(
        respond,
        examples=[
            "How do I sign up for FlowBar?",
            "Can I cancel anytime?",
            "What's the free plan include?",
            "How do I create a task?",
            "Do you have a mobile app?",
        ],
        cache_examples=False,
    )

    with gr.Accordion("Customize Your Bot", open=False):
        name_input = gr.Textbox(label="Bot Name", value=DEFAULT_BOT_NAME)
        tagline_input = gr.Textbox(label="Tagline", value=DEFAULT_TAGLINE, lines=2)
        color_input = gr.Dropdown(
            label="Accent Color",
            choices=PRESET_COLORS,
            value=DEFAULT_ACCENT,
        )
        apply_btn = gr.Button("Apply", variant="primary", size="sm")
        apply_btn.click(
            update_all,
            inputs=[name_input, tagline_input, color_input],
            outputs=[header, css_holder],
        )

demo.launch(server_name="0.0.0.0", server_port=7860)