#!/bin/sh
# Install Miguel F. Serna's Neovim config. Documentation: https://www.mfserna.dev/nvim
#
#   curl -fsSL https://www.mfserna.dev/nvim/install.sh | sh
#   curl -fsSL https://www.mfserna.dev/nvim/install.sh | sh -s -- --install-nvim
#   curl -fsSL https://www.mfserna.dev/nvim/install.sh | sh -s -- --minimal
#
# Flags
#   --install-nvim   If nvim is missing or older than 0.11, install the official
#                    release tarball into ~/.local/opt/nvim (no sudo, no package
#                    manager) and link ~/.local/bin/nvim.
#   --minimal        Install init.min.lua only: no plugins, no git, no network
#                    after the download.
#   --no-sync        Write the files but skip the headless plugin install.
#   --dry-run        Print every step without touching the filesystem.
#   --help           Show this text.
#
# Environment
#   NVIM_CONFIG_URL  Base URL for the files (default https://www.mfserna.dev/nvim).
#   XDG_CONFIG_HOME  Config root (default ~/.config). The config lands in $XDG_CONFIG_HOME/nvim.
#
# Writes only to: $XDG_CONFIG_HOME/nvim, $XDG_DATA_HOME/nvim (plugins), and,
# with --install-nvim, ~/.local/opt/nvim and ~/.local/bin/nvim. An existing
# config that differs from this one is moved to nvim.bak.<timestamp>, never deleted.

set -eu

BASE="${NVIM_CONFIG_URL:-https://www.mfserna.dev/nvim}"
CONFIG_DIR="${XDG_CONFIG_HOME:-$HOME/.config}/nvim"
DATA_DIR="${XDG_DATA_HOME:-$HOME/.local/share}/nvim"
NVIM_PREFIX="$HOME/.local/opt/nvim"
NVIM_LINK="$HOME/.local/bin/nvim"
MIN_MAJOR=0
MIN_MINOR=11

INSTALL_NVIM=0
MINIMAL=0
SYNC=1
DRY_RUN=0

usage() {
    cat <<'EOF'
Install Miguel F. Serna's Neovim config. Documentation: https://www.mfserna.dev/nvim

  curl -fsSL https://www.mfserna.dev/nvim/install.sh | sh
  curl -fsSL https://www.mfserna.dev/nvim/install.sh | sh -s -- --install-nvim
  curl -fsSL https://www.mfserna.dev/nvim/install.sh | sh -s -- --minimal

Flags
  --install-nvim   If nvim is missing or older than 0.11, install the official
                   release tarball into ~/.local/opt/nvim (no sudo) and link
                   ~/.local/bin/nvim.
  --minimal        Install init.min.lua only: no plugins, no git, no network
                   after the download.
  --no-sync        Write the files but skip the headless plugin install.
  --dry-run        Print every step without touching the filesystem.
  --help           Show this text.

Environment
  NVIM_CONFIG_URL  Base URL for the files (default https://www.mfserna.dev/nvim).
  XDG_CONFIG_HOME  Config root (default ~/.config). The config lands in $XDG_CONFIG_HOME/nvim.
EOF
}

while [ $# -gt 0 ]; do
    case "$1" in
        --install-nvim) INSTALL_NVIM=1 ;;
        --minimal) MINIMAL=1 ;;
        --no-sync) SYNC=0 ;;
        --dry-run) DRY_RUN=1 ;;
        -h|--help) usage; exit 0 ;;
        *) printf 'unknown flag: %s\n' "$1" >&2; exit 2 ;;
    esac
    shift
done

log() { printf '%s\n' "$*"; }
die() { printf 'error: %s\n' "$*" >&2; exit 1; }
have() { command -v "$1" >/dev/null 2>&1; }
run() {
    if [ "$DRY_RUN" -eq 1 ]; then log "+ $*"; else "$@"; fi
}

TMP=$(mktemp -d 2>/dev/null || mktemp -d -t nvimcfg)
trap 'rm -rf "$TMP"' EXIT INT TERM

fetch() {
    # fetch <relative path> <destination>
    mkdir -p "$(dirname "$2")"
    if have curl; then
        curl -fsSL "$BASE/$1" -o "$2"
    elif have wget; then
        wget -qO "$2" "$BASE/$1"
    else
        die "need curl or wget to download $BASE/$1"
    fi
}

nvim_ok() {
    # Succeeds when the nvim on PATH is at least $MIN_MAJOR.$MIN_MINOR.
    have nvim || return 1
    version=$(nvim --version 2>/dev/null | sed -n '1s/^NVIM v\([0-9][0-9]*\)\.\([0-9][0-9]*\).*/\1 \2/p')
    [ -n "$version" ] || return 1
    major=${version% *}
    minor=${version#* }
    [ "$major" -gt "$MIN_MAJOR" ] || { [ "$major" -eq "$MIN_MAJOR" ] && [ "$minor" -ge "$MIN_MINOR" ]; }
}

install_nvim() {
    os=$(uname -s)
    arch=$(uname -m)
    case "$os-$arch" in
        Linux-x86_64) asset=nvim-linux-x86_64.tar.gz ;;
        Linux-aarch64|Linux-arm64) asset=nvim-linux-arm64.tar.gz ;;
        Darwin-arm64) asset=nvim-macos-arm64.tar.gz ;;
        Darwin-x86_64) asset=nvim-macos-x86_64.tar.gz ;;
        *) die "no official Neovim tarball for $os/$arch; install nvim >= $MIN_MAJOR.$MIN_MINOR yourself and rerun" ;;
    esac
    url="https://github.com/neovim/neovim/releases/download/stable/$asset"
    log "Installing Neovim stable from $url"
    if [ "$DRY_RUN" -eq 1 ]; then
        log "+ extract to $NVIM_PREFIX and link $NVIM_LINK"
        return
    fi
    have tar || die "need tar to unpack $asset"
    if have curl; then curl -fsSL "$url" -o "$TMP/$asset"; else wget -qO "$TMP/$asset" "$url"; fi
    rm -rf "$NVIM_PREFIX"
    mkdir -p "$NVIM_PREFIX" "$(dirname "$NVIM_LINK")"
    tar -xzf "$TMP/$asset" --strip-components=1 -C "$NVIM_PREFIX"
    ln -sf "$NVIM_PREFIX/bin/nvim" "$NVIM_LINK"
    bin_dir=$(dirname "$NVIM_LINK")
    case ":$PATH:" in
        *":$bin_dir:"*) ;;
        *) log "note: $bin_dir is not on PATH; add it in your shell profile" ;;
    esac
    PATH="$bin_dir:$PATH"
    export PATH
    nvim_ok || die "installed $NVIM_PREFIX/bin/nvim but it did not report >= $MIN_MAJOR.$MIN_MINOR (old glibc? try the AppImage from https://github.com/neovim/neovim/releases)"
}

# 1. Neovim
if nvim_ok; then
    log "Found $(nvim --version | sed -n 1p) at $(command -v nvim)"
elif [ "$INSTALL_NVIM" -eq 1 ]; then
    install_nvim
else
    die "nvim >= $MIN_MAJOR.$MIN_MINOR not found. Rerun with --install-nvim to fetch the official tarball into ~/.local, or install it with your package manager."
fi

# 2. Download
if [ "$MINIMAL" -eq 1 ]; then
    FILES="init.min.lua"
else
    have git || die "git is required: init.lua bootstraps lazy.nvim with git clone. Use --minimal for a plugin-free config."
    FILES="init.lua lazy-lock.json syntax/baml.vim"
fi
for file in $FILES; do
    log "Fetching $BASE/$file"
    fetch "$file" "$TMP/config/$file"
done
if [ "$MINIMAL" -eq 1 ]; then
    mv "$TMP/config/init.min.lua" "$TMP/config/init.lua"
fi

# 3. Back up, then install
if [ -e "$CONFIG_DIR" ]; then
    if [ -f "$CONFIG_DIR/init.lua" ] && cmp -s "$CONFIG_DIR/init.lua" "$TMP/config/init.lua" 2>/dev/null; then
        log "Existing config at $CONFIG_DIR already matches; refreshing in place"
    else
        backup="$CONFIG_DIR.bak.$(date +%Y%m%d%H%M%S)"
        log "Moving existing $CONFIG_DIR to $backup"
        run mv "$CONFIG_DIR" "$backup"
    fi
fi
run mkdir -p "$CONFIG_DIR"
if [ "$DRY_RUN" -eq 1 ]; then
    log "+ copy $FILES into $CONFIG_DIR"
else
    (cd "$TMP/config" && find . -type f) | while IFS= read -r path; do
        mkdir -p "$CONFIG_DIR/$(dirname "$path")"
        cp "$TMP/config/$path" "$CONFIG_DIR/$path"
    done
fi
log "Installed config to $CONFIG_DIR"

# 4. Plugins
if [ "$MINIMAL" -eq 0 ] && [ "$SYNC" -eq 1 ]; then
    log "Installing plugins pinned in lazy-lock.json (headless, may take a minute)"
    run nvim --headless "+Lazy! restore" +qa
    if [ "$DRY_RUN" -eq 0 ]; then
        expected=$(grep -c '"branch"' "$CONFIG_DIR/lazy-lock.json")
        installed=$(ls -1 "$DATA_DIR/lazy" 2>/dev/null | wc -l | tr -d ' ')
        if [ "$installed" -ge "$expected" ]; then
            log "Plugins: $installed/$expected present in $DATA_DIR/lazy"
        else
            log "warning: $installed/$expected plugins present; open nvim and run :Lazy restore"
        fi
    fi
fi

# 5. Report optional tooling
if [ "$MINIMAL" -eq 0 ]; then
    log ""
    log "Optional tools (missing ones only reduce features, nothing fails):"
    for tool in rg cc make tree-sitter node cargo go java python3; do
        if have "$tool"; then state=ok; else state=missing; fi
        log "  $tool: $state"
    done
    log "Language servers install through :Mason on first interactive launch."
fi

log ""
log "Done. Verify with: nvim --headless +checkhealth +qa"