#!/usr/bin/env bash
set -euo pipefail
APP=opencode

MUTED='\033[0;2m'
RED='\033[0;31m'
ORANGE='\033[38;2;255;140;0m'
NC='\033[0m' # No Color

requested_version=${VERSION:-}

raw_os=$(uname -s)
os=$(echo "$raw_os" | tr '[:upper:]' '[:lower:]')
# Normalize various Unix-like identifiers
case "$raw_os" in
  Darwin*) os="darwin" ;;
  Linux*) os="linux" ;;
  MINGW*|MSYS*|CYGWIN*) os="windows" ;;
 esac
arch=$(uname -m)

if [[ "$arch" == "aarch64" ]]; then
  arch="arm64"
elif [[ "$arch" == "x86_64" ]]; then
  arch="x64"
fi

filename="$APP-$os-$arch.zip"


case "$filename" in
    *"-linux-"*)
        [[ "$arch" == "x64" || "$arch" == "arm64" ]] || exit 1
    ;;
    *"-darwin-"*)
        [[ "$arch" == "x64" || "$arch" == "arm64" ]] || exit 1
    ;;
    *"-windows-"*)
        [[ "$arch" == "x64" ]] || exit 1
    ;;
    *)
        echo -e "${RED}Unsupported OS/Arch: $os/$arch${NC}"
        exit 1
    ;;
esac

if ! command -v unzip >/dev/null 2>&1; then
    echo -e "${RED}Error: 'unzip' is required but not installed.${NC}"
    exit 1
fi

INSTALL_DIR=$HOME/.opencode/bin
mkdir -p "$INSTALL_DIR"

if [ -z "$requested_version" ]; then
    url="https://github.com/sst/opencode/releases/latest/download/$filename"
    specific_version=$(curl -s https://api.github.com/repos/sst/opencode/releases/latest | sed -n 's/.*"tag_name": *"v\([^"]*\)".*/\1/p')

    if [[ $? -ne 0 || -z "$specific_version" ]]; then
        echo -e "${RED}Failed to fetch version information${NC}"
        exit 1
    fi
else
    url="https://github.com/sst/opencode/releases/download/v${requested_version}/$filename"
    specific_version=$requested_version
fi

print_message() {
    local level=$1
    local message=$2
    local color=""

    case $level in
        info) color="${NC}" ;;
        warning) color="${NC}" ;;
        error) color="${RED}" ;;
    esac

    echo -e "${color}${message}${NC}"
}

check_version() {
    if command -v opencode >/dev/null 2>&1; then
        opencode_path=$(which opencode)


        ## TODO: check if version is installed
        # installed_version=$(opencode version)
        installed_version="0.0.1"
        installed_version=$(echo $installed_version | awk '{print $2}')

        if [[ "$installed_version" != "$specific_version" ]]; then
            print_message info "${MUTED}Installed version: ${NC}$installed_version."
        else
            print_message info "${MUTED}Version ${NC}$specific_version${MUTED} already installed"
            exit 0
        fi
    fi
}

unbuffered_sed() {
    if echo | sed -u -e "" >/dev/null 2>&1; then
        sed -nu "$@"
    elif echo | sed -l -e "" >/dev/null 2>&1; then
        sed -nl "$@"
    else
        local pad="$(printf "\n%512s" "")"
        sed -ne "s/$/\\${pad}/" "$@"
    fi
}

print_progress() {
    local bytes="$1"
    local length="$2"
    [ "$length" -gt 0 ] || return 0

    local width=50
    local percent=$(( bytes * 100 / length ))
    [ "$percent" -gt 100 ] && percent=100
    local on=$(( percent * width / 100 ))
    local off=$(( width - on ))

    local filled=$(printf "%*s" "$on" "")
    filled=${filled// /■}
    local empty=$(printf "%*s" "$off" "")
    empty=${empty// /･}

    printf "\r${ORANGE}%s%s %3d%%${NC}" "$filled" "$empty" "$percent" >&4
}

download_with_progress() {
    local url="$1"
    local output="$2"

    if [ -t 2 ]; then
        exec 4>&2
    else
        exec 4>/dev/null
    fi

    local tmp_dir=${TMPDIR:-/tmp}
    local basename="${tmp_dir}/opencode_install_$$"
    local tracefile="${basename}.trace"

    rm -f "$tracefile"
    mkfifo "$tracefile"

    # Hide cursor
    printf "\033[?25l" >&4

    trap "trap - RETURN; rm -f \"$tracefile\"; printf '\033[?25h' >&4; exec 4>&-" RETURN

    (
        curl --trace-ascii "$tracefile" -s -L -o "$output" "$url"
    ) &
    local curl_pid=$!

    unbuffered_sed \
        -e 'y/ACDEGHLNORTV/acdeghlnortv/' \
        -e '/^0000: content-length:/p' \
        -e '/^<= recv data/p' \
        "$tracefile" | \
    {
        local length=0
        local bytes=0
        
        while IFS=" " read -r -a line; do
            [ "${#line[@]}" -lt 2 ] && continue
            local tag="${line[0]} ${line[1]}"
            
            if [ "$tag" = "0000: content-length:" ]; then
                length="${line[2]}"
                length=$(echo "$length" | tr -d '\r')
                bytes=0
            elif [ "$tag" = "<= recv" ]; then
                local size="${line[3]}"
                bytes=$(( bytes + size ))
                if [ "$length" -gt 0 ]; then
                    print_progress "$bytes" "$length"
                fi
            fi
        done
    }

    wait $curl_pid
    local ret=$?
    echo "" >&4
    return $ret
}

download_and_install() {
    print_message info "\n${MUTED}Installing ${NC}opencode ${MUTED}version: ${NC}$specific_version"
    mkdir -p opencodetmp && cd opencodetmp
    
    if [[ "$os" == "windows" ]] || ! download_with_progress "$url" "$filename"; then
        # Fallback to standard curl on Windows or if custom progress fails
        curl -# -L -o "$filename" "$url"
    fi

    unzip -q "$filename"
    mv opencode "$INSTALL_DIR"
    chmod 755 "${INSTALL_DIR}/opencode"
    cd .. && rm -rf opencodetmp
}

check_version
download_and_install


add_to_path() {
    local config_file=$1
    local command=$2

    if grep -Fxq "$command" "$config_file"; then
        print_message info "Command already exists in $config_file, skipping write."
    elif [[ -w $config_file ]]; then
        echo -e "\n# opencode" >> "$config_file"
        echo "$command" >> "$config_file"
        print_message info "${MUTED}Successfully added ${NC}opencode ${MUTED}to \$PATH in ${NC}$config_file"
    else
        print_message warning "Manually add the directory to $config_file (or similar):"
        print_message info "  $command"
    fi
}

XDG_CONFIG_HOME=${XDG_CONFIG_HOME:-$HOME/.config}

current_shell=$(basename "$SHELL")
case $current_shell in
    fish)
        config_files="$HOME/.config/fish/config.fish"
    ;;
    zsh)
        config_files="$HOME/.zshrc $HOME/.zshenv $XDG_CONFIG_HOME/zsh/.zshrc $XDG_CONFIG_HOME/zsh/.zshenv"
    ;;
    bash)
        config_files="$HOME/.bashrc $HOME/.bash_profile $HOME/.profile $XDG_CONFIG_HOME/bash/.bashrc $XDG_CONFIG_HOME/bash/.bash_profile"
    ;;
    ash)
        config_files="$HOME/.ashrc $HOME/.profile /etc/profile"
    ;;
    sh)
        config_files="$HOME/.ashrc $HOME/.profile /etc/profile"
    ;;
    *)
        # Default case if none of the above matches
        config_files="$HOME/.bashrc $HOME/.bash_profile $XDG_CONFIG_HOME/bash/.bashrc $XDG_CONFIG_HOME/bash/.bash_profile"
    ;;
esac

config_file=""
for file in $config_files; do
    if [[ -f $file ]]; then
        config_file=$file
        break
    fi
done

if [[ -z $config_file ]]; then
    print_message error "No config file found for $current_shell. Checked files: ${config_files[@]}"
    exit 1
fi

if [[ ":$PATH:" != *":$INSTALL_DIR:"* ]]; then
    case $current_shell in
        fish)
            add_to_path "$config_file" "fish_add_path $INSTALL_DIR"
        ;;
        zsh)
            add_to_path "$config_file" "export PATH=$INSTALL_DIR:\$PATH"
        ;;
        bash)
            add_to_path "$config_file" "export PATH=$INSTALL_DIR:\$PATH"
        ;;
        ash)
            add_to_path "$config_file" "export PATH=$INSTALL_DIR:\$PATH"
        ;;
        sh)
            add_to_path "$config_file" "export PATH=$INSTALL_DIR:\$PATH"
        ;;
        *)
            export PATH=$INSTALL_DIR:$PATH
            print_message warning "Manually add the directory to $config_file (or similar):"
            print_message info "  export PATH=$INSTALL_DIR:\$PATH"
        ;;
    esac
fi

if [ -n "${GITHUB_ACTIONS-}" ] && [ "${GITHUB_ACTIONS}" == "true" ]; then
    echo "$INSTALL_DIR" >> $GITHUB_PATH
    print_message info "Added $INSTALL_DIR to \$GITHUB_PATH"
fi

echo -e ""
echo -e "${MUTED}                    ${NC}             ▄     "
echo -e "${MUTED}█▀▀█ █▀▀█ █▀▀█ █▀▀▄ ${NC}█▀▀▀ █▀▀█ █▀▀█ █▀▀█"
echo -e "${MUTED}█░░█ █░░█ █▀▀▀ █░░█ ${NC}█░░░ █░░█ █░░█ █▀▀▀"
echo -e "${MUTED}▀▀▀▀ █▀▀▀ ▀▀▀▀ ▀  ▀ ${NC}▀▀▀▀ ▀▀▀▀ ▀▀▀▀ ▀▀▀▀"
echo -e ""
echo -e ""
echo -e "${MUTED}To get started, navigate to a project and run:${NC}"
echo -e "opencode                   ${MUTED}Use free models${NC}"
echo -e "opencode auth login        ${MUTED}Add paid provider API keys${NC}"
echo -e "opencode help              ${MUTED}List commands and options${NC}"
echo -e ""
echo -e "${MUTED}For more information visit ${NC}https://opencode.ai/docs"
echo -e ""
echo -e ""