import os
import gradio as gr
from git import InvalidGitRepositoryError
from git_graph import render_branch_graph

DEFAULT_REPO_PATH = os.environ.get("REPO_PATH", os.getcwd())


def draw_graph(repo_path: str, next_commit_message: str):
    repo_path = repo_path.strip() or DEFAULT_REPO_PATH
    try:
        return render_branch_graph(repo_path, next_commit_message)
    except InvalidGitRepositoryError:
        raise gr.Error(f"'{repo_path}' is not a git repository.")


with gr.Blocks(title="Git Branch Visualizer", theme=gr.themes.Base()) as demo:
    gr.Markdown("## Git Branch Graph Visualizer")
    gr.Markdown(
        "Shows all local **and remote** branches as a commit DAG. "
        "Type a commit message to preview **where the next commit lands** (gold ghost node)."
    )

    with gr.Row():
        repo_path_input = gr.Textbox(
            label="Repository path",
            value=DEFAULT_REPO_PATH,
            placeholder="/path/to/your/repo",
            scale=3,
        )
        next_commit_input = gr.Textbox(
            label="Next commit message (preview)",
            placeholder="feat: add new feature",
            scale=2,
        )

    render_button = gr.Button("Render Graph", variant="primary")

    graph_output = gr.Plot(label="Branch Graph")
    info_output = gr.Markdown()

    render_button.click(
        fn=draw_graph,
        inputs=[repo_path_input, next_commit_input],
        outputs=[graph_output, info_output],
    )
    demo.load(
        fn=draw_graph,
        inputs=[repo_path_input, next_commit_input],
        outputs=[graph_output, info_output],
    )

if __name__ == "__main__":
    demo.launch()