#!/bin/bash
# bman - view man pages in browser

set -o pipefail

show_help() {
    cat <<EOF
Usage: bman [OPTIONS] [MAN_PAGE...]

Display man pages in your web browser with custom CSS styling.

Options:
  --dark          Use dark theme
  --modern        Use modern theme
  -h, --help      Show this help message

If no MAN_PAGE is given and fzf is installed, opens an interactive fzf selection
where you can select multiple pages (TAB to toggle).

Examples:
  bman geany
  bman --dark ls
  bman --modern bash

Requires: man, xdg-open (or similar), sed, and fzf (for interactive mode).
EOF
}

# Check core dependencies
for cmd in man xdg-open sed; do
    if ! command -v "$cmd" >/dev/null 2>&1; then
        echo "Error: required command '$cmd' not found." >&2
        exit 1
    fi
done

# Parse options
theme="default"
while [[ $# -gt 0 ]]; do
    case "$1" in
        --dark)
            theme="dark"
            shift
            ;;
        --modern)
            theme="modern"
            shift
            ;;
        -h|--help)
            show_help
            exit 0
            ;;
        --) # end of options
            shift
            break
            ;;
        -*)
            echo "Error: unknown option $1" >&2
            show_help
            exit 1
            ;;
        *)
            break # non-option argument
            ;;
    esac
done

# If no man pages given, try fzf interactive mode
if [ $# -eq 0 ]; then
    # Check if fzf is available
    if ! command -v fzf >/dev/null 2>&1; then
        echo "Error: fzf is not installed. Please install it (e.g., 'sudo apt install fzf' or from https://github.com/junegunn/fzf)." >&2
        show_help
        exit 1
    fi

    # Generate list of all man page names (strip section numbers)
    mapfile -t pages < <(
        man -k . 2>/dev/null |
        awk '{print $1}' |
        sed 's/([0-9])//' |
        sort -u |
        fzf --height=80% --marker="*" --multi --bind='tab:toggle' --reverse --prompt="Select man page(s) (TAB to toggle): "
    )

    # If user cancels (no selection), exit gracefully
    if [ ${#pages[@]} -eq 0 ]; then
        echo "No selection made. Exiting."
        exit 0
    fi

    # Replace positional parameters with the selected pages
    set -- "${pages[@]}"
fi

# Persistent cache directory for HTML files
CACHE_DIR="$HOME/.cache/bman"
mkdir -p "$CACHE_DIR" || { echo "Error: failed to create cache directory" >&2; exit 1; }
chmod 700 "$CACHE_DIR"

# Clean up HTML files older than 1 minute
find "$CACHE_DIR" -name "*.html" -type f -mmin +1 -delete 2>/dev/null

# Build CSS based on theme (collapse newlines to one line for sed substitution)
case "$theme" in
    dark)
        css_raw=$(cat <<'CSS'
<!-- Bronto custom css -->
<style type="text/css">
    /* centered, 85‑character‑wide container */
    body {
        max-width: 85ch;
        margin: 0 auto;
        padding: 0 1em;
        background-color: #333D4D;
        background-color: #13181B;
        background-image: url(https://brontosaurusrex.github.io/public/mozillaGrain.png);
        color: #96b0bf;
        line-height: 1.6;
    }
    p       { margin-top: 0; margin-bottom: 0; vertical-align: top; font-family: 'Noto Serif light', serif; font-size: large }
    a       { font-family: 'Noto Serif light', serif; font-size: large }
    pre     { margin-top: 0; margin-bottom: 0; vertical-align: top; font-size: large }
    table   { margin-top: 0; margin-bottom: 0; vertical-align: top }
    h1      { text-align: center; font-family: 'Noto Serif light', serif; font-size: xx-large; color: #28c1d7 }
    h2      { font-family: 'Noto Serif light', serif; color: #cb6317; }
    hr      { border-top: 1px solid black; visibility: hidden; }
    a:link {
        text-decoration: none;
        color: #4BB2C9;
    }
    a:visited {
        text-decoration: none;
        color: #4BB2C9;
    }
    a:hover {
        text-decoration: underline;
        color: #4BB2C9;
    }
    a:active {
        text-decoration: underline;
        color: #4BB2C9;
    }
    b {
        color: #4BB2C9;
    }
</style>
CSS
)
        ;;
    modern)
        css_raw=$(cat <<'CSS'
<!-- Bronto custom css -->
<style type="text/css">
    /* centered, 85‑character‑wide container */
    body {
        max-width: 85ch;
        margin: 0 auto;
        padding: 0 1em;
        background-color: #F5F5F5;
        color: #111111;
        line-height: 1.6;
    }
    p       { margin-top: 0; margin-bottom: 0; vertical-align: top; font-family: 'Latin Modern Roman Unslanted', serif; font-size: large }
    a       { font-family: 'Latin Modern Roman', serif; font-size: large }
    pre     { margin-top: 0; margin-bottom: 0; vertical-align: top; font-size: large }
    table   { margin-top: 0; margin-bottom: 0; vertical-align: top }
    h1      { text-align: center; font-family: 'Latin Modern Roman', serif; font-size: xx-large }
    h2      { text-align: center; font-family: 'Latin Modern Roman', sans; }
    hr      { border-top: 1px solid black; visibility: hidden; }
    a:link {
        text-decoration: none;
    }
    a:visited {
        text-decoration: none;
    }
    a:hover {
        text-decoration: underline;
    }
    a:active {
        text-decoration: underline;
    }
</style>
CSS
)
        ;;
    default|*)
        css_raw=$(cat <<'CSS'
<!-- Bronto custom css -->
<style type="text/css">
    /* centered, 85‑character‑wide container */
    body {
        max-width: 85ch;
        margin: 0 auto;
        padding: 0 1em;
        background-color: #F5F5F5;
        color: #111111;
        line-height: 1.6;
    }
    p       { margin-top: 0; margin-bottom: 0; vertical-align: top; font-family: 'Noto Serif', serif; font-size: large }
    a       { font-family: 'Noto Sans', sans; font-size: large }
    pre     { margin-top: 0; margin-bottom: 0; vertical-align: top; font-size: large }
    table   { margin-top: 0; margin-bottom: 0; vertical-align: top }
    h1      { text-align: center; font-family: 'Noto Serif', serif; font-size: xxx-large }
    h2      { font-family: 'Noto Sans', sans; font-size: xx-large }
    hr      { border-top: 1px solid black; visibility: hidden; }
    a:link {
        text-decoration: none;
    }
    a:visited {
        text-decoration: none;
    }
    a:hover {
        text-decoration: underline;
    }
    a:active {
        text-decoration: underline;
    }
</style>
CSS
)
        ;;
esac

# Collapse newlines to make the CSS a single line for sed substitution
css="$(echo "$css_raw" | tr '\n' ' ')"

# Process each man page
for man in "$@"; do
    # Create a temporary file in the cache directory
    html_file=$(mktemp -p "$CACHE_DIR" --suffix=".html" 2>/dev/null) || {
        echo "Warning: failed to create temporary file for '$man', skipping." >&2
        continue
    }

    # Generate HTML version of the man page
    if ! man -Thtml "$man" > "$html_file.tmp" 2>/dev/null; then
        echo "Warning: man page for '$man' not found, skipping." >&2
        rm -f "$html_file" "$html_file.tmp" 2>/dev/null
        continue
    fi

    # Insert the custom CSS before </head>
    sed "s|^</head>*|${css}</head>|g" < "$html_file.tmp" > "$html_file"
    rm -f "$html_file.tmp"

    # Open the HTML file in the default browser
    xdg-open "$html_file" 2>/dev/null &
done