#!/usr/bin/env bash
# Usage:
#   bash <(curl -fsSL <raw-url>)     install mode
#   wget -qO- <raw-url> | bash       install mode
#
# Assumes Neovim is already installed and functional on the machine.
# Wires up:
#   - telescope.nvim   (Ctrl-P fuzzy file finder)
#   - bufferline.nvim  (always-visible buffer tabline)
#   - lazy.nvim        (plugin manager, bootstrapped on first nvim launch)
#
# Keymaps installed:
#   <C-p>       find files (telescope)
#   <S-h>       previous buffer
#   <S-l>       next buffer
#   <leader>x   close current buffer   (leader defaults to space)

set -e

NVIM_MIN_VERSION="0.9.0"   # telescope.nvim's stated minimum; also satisfies lazy.nvim/bufferline.nvim

# ---- version checks (fail closed) --------------------------------

_version_ge() {
    # returns 0 if $1 >= $2, for dotted "major.minor.patch" strings
    local IFS=.
    local -a v1=($1) v2=($2)
    local i a b
    for i in 0 1 2; do
        a=${v1[i]:-0}
        b=${v2[i]:-0}
        if (( a > b )); then return 0; fi
        if (( a < b )); then return 1; fi
    done
    return 0
}

if ! command -v nvim >/dev/null 2>&1; then
    echo "ERROR: nvim not found on PATH. This script assumes Neovim is already installed." >&2
    exit 1
fi

nvim_version_raw="$(nvim --version | head -n1)"
nvim_version="$(printf '%s' "$nvim_version_raw" | grep -oE '[0-9]+\.[0-9]+\.[0-9]+' | head -n1)"

if [ -z "$nvim_version" ]; then
    echo "ERROR: could not parse Neovim version from: $nvim_version_raw" >&2
    exit 1
fi

if ! _version_ge "$nvim_version" "$NVIM_MIN_VERSION"; then
    echo "ERROR: Neovim >= $NVIM_MIN_VERSION required (found $nvim_version)." >&2
    echo "       telescope.nvim and bufferline.nvim need a recent Neovim." >&2
    exit 1
fi

if ! command -v git >/dev/null 2>&1; then
    echo "ERROR: git not found on PATH. Required by lazy.nvim to install plugins." >&2
    exit 1
fi

if ! command -v rg >/dev/null 2>&1; then
    echo "WARNING: ripgrep (rg) not found. File finding will still work but will be slower," >&2
    echo "         and Telescope live_grep won't work. Install ripgrep for the full experience." >&2
fi

# ---- paths ---------------------------------------------------------

CONFIG_DIR="${XDG_CONFIG_HOME:-$HOME/.config}/nvim"
LUA_DIR="$CONFIG_DIR/lua"
PLUGIN_FILE="$LUA_DIR/supraa-nvim-setup.lua"

_write_plugin_file() {
    cat > "$PLUGIN_FILE" << 'EOF'
-- ------------------------------------------------------------------
-- supraa-nvim-setup.lua — telescope + bufferline, bootstrapped via lazy.nvim
-- ------------------------------------------------------------------

if vim.g.mapleader == nil then
    vim.g.mapleader = " "
end

vim.opt.termguicolors = true

-- bootstrap lazy.nvim
local lazypath = vim.fn.stdpath("data") .. "/lazy/lazy.nvim"
if not vim.loop.fs_stat(lazypath) then
    vim.fn.system({
        "git", "clone", "--filter=blob:none",
        "https://github.com/folke/lazy.nvim.git",
        "--branch=stable",
        lazypath,
    })
end
vim.opt.rtp:prepend(lazypath)

require("lazy").setup({
    {
        "nvim-telescope/telescope.nvim",
        tag = "0.1.8",
        dependencies = { "nvim-lua/plenary.nvim" },
    },
    {
        "akinsho/bufferline.nvim",
        version = "*",
        dependencies = { "nvim-tree/nvim-web-devicons" },
    },
})

require("bufferline").setup({
    options = {
        always_show_bufferline = true,
        diagnostics = "nvim_lsp",
    },
})

-- fuzzy file finder: Ctrl-P
vim.keymap.set("n", "<C-p>", require("telescope.builtin").find_files, { desc = "Telescope: find files" })

-- buffer navigation: Shift-H / Shift-L
vim.keymap.set("n", "<S-h>", "<cmd>BufferLineCyclePrev<CR>", { desc = "Previous buffer" })
vim.keymap.set("n", "<S-l>", "<cmd>BufferLineCycleNext<CR>", { desc = "Next buffer" })

-- close buffer: <leader>x (space+x by default)
vim.keymap.set("n", "<leader>x", "<cmd>bdelete<CR>", { desc = "Close buffer" })
EOF
}

_hook_init() {
    local init_lua="$CONFIG_DIR/init.lua"
    local init_vim="$CONFIG_DIR/init.vim"
    local marker="supraa-nvim-setup"

    if [ -f "$init_vim" ] && [ ! -f "$init_lua" ]; then
        if grep -q "$marker" "$init_vim" 2>/dev/null; then
            echo "  already hooked into $init_vim"
        else
            printf '\nlua require("supraa-nvim-setup")\n' >> "$init_vim"
            echo "  hooked into $init_vim"
        fi
        return
    fi

    touch "$init_lua"
    if grep -q "$marker" "$init_lua" 2>/dev/null; then
        echo "  already hooked into $init_lua"
    else
        printf '\nrequire("supraa-nvim-setup")\n' >> "$init_lua"
        echo "  hooked into $init_lua"
    fi
}

# ---- main ----------------------------------------------------------

echo "Installing Neovim setup (telescope + bufferline) ..."
mkdir -p "$LUA_DIR"
_write_plugin_file
echo "  written $PLUGIN_FILE"

echo "Hooking into Neovim config ..."
_hook_init

echo ""
echo "Done. Open nvim — plugins install automatically on first launch (lazy.nvim bootstrap)."
echo "Keymaps: <C-p> find files | <S-h>/<S-l> prev/next buffer | <leader>x close buffer (leader = space)"