#!/bin/bash

# Enhanced Himalaya Email Management Script
# Features: Auto-discovery, smart navigation, streamlined UX

# Function to get available message IDs from himalaya
get_available_message_ids() {
    himalaya envelope list | awk 'NR > 2 && /^\| [0-9]/ {gsub(/[| ]/, "", $2); if($2 ~ /^[0-9]+$/) print $2}' | sort -n
}

# Function to get the latest (most recent) message ID
get_latest_message_id() {
    get_available_message_ids | tail -1
}

# Function to find the next valid message ID
find_next_message_id() {
    local current_id="$1"
    get_available_message_ids | awk -v current="$current_id" '$1 > current {print $1; exit}'
}

# Function to find the previous valid message ID
find_previous_message_id() {
    local current_id="$1"
    get_available_message_ids | awk -v current="$current_id" '$1 < current {prev=$1} END {if(prev) print prev}'
}

# Function to refresh the vim-himalaya buffer
refresh_vim_himalaya() {
    if [ -S "/tmp/nvim-server" ]; then
        nvim --server /tmp/nvim-server --remote-send "Himalaya<CR>" 2>/dev/null
    fi
}

# Function to read a single character without waiting for Enter
read_char() {
    stty -echo -icanon time 0 min 1
    char=$(dd bs=1 count=1 2>/dev/null)
    stty echo icanon
    echo "$char"
}

# Function to safely run the himalaya command and handle failures
run_himalaya_message_read() {
    local message_id="$1"
    local temp_output
    temp_output=$(himalaya message read "$message_id" 2>&1)
    local exit_code=$?
    
    if [ $exit_code -eq 0 ]; then
        # Choose email processor based on availability
        local email_processor
        if [ -f "email_processor.awk" ]; then
            email_processor="awk -f email_processor.awk"
        elif command -v python3 >/dev/null 2>&1 && [ -f "email_processor.py" ]; then
            email_processor="python3 email_processor.py"
        else
            email_processor="cat"  # fallback to no processing
        fi
        
        # Process email content, then render with glow and display with less
        echo "$temp_output" | \
            $email_processor | \
            # bat
            glow --width 100 -p 
            # less -R -X -F
        return 0
    else
        echo "Failed to open message $message_id."
        return 1
    fi
}

# Function to create a task for the current message
create_task_for_message() {
    local message_id="$1"
    read -p "Task title: " task_title
    if [ -n "$task_title" ]; then
        if command -v task >/dev/null 2>&1; then
            task add "Followup on email $message_id - $task_title" \
                --project "Email" \
                --due "$(date -d '+1 week' +%Y-%m-%d)" \
                --priority "P3" \
                --tags "email"
            echo "Task created for message $message_id."
        else
            echo "TaskWarrior not found. Task not created."
        fi
    else
        echo "No task title provided. Task not created."
    fi
}

# Function to display the action menu and handle user choice
show_action_menu() {
    local current_id="$1"
    
    # Draw a nice border above the menu
    echo ""
    echo "════════════════════════════════════════════════════════════════════════════════"
    echo "                                     ACTIONS"
    echo "════════════════════════════════════════════════════════════════════════════════"
    echo ""
    echo "  t) Create task for this message"
    echo "  d) Delete message"
    echo "  a) Archive message"
    echo "  n) Next message"
    echo "  p) Previous message"
    echo "  r) Reopen/redisplay current message"
    echo "  q) Quit"
    echo ""
    echo "────────────────────────────────────────────────────────────────────────────────"
    echo -n "Enter choice: "
    
    local choice=$(read_char)
    echo "$choice"  # Echo for feedback
    
    # Clear screen after choice is made
    clear
    
    case "$choice" in
        t|T)
            create_task_for_message "$current_id"
            echo "Press any key to continue..."
            read_char > /dev/null
            process_message "$current_id"
            ;;
        d|D)
            echo "Deleting message $current_id..."
            if himalaya message delete "$current_id"; then
                echo "Message $current_id deleted successfully."
                refresh_vim_himalaya
                # Try to open next available message
                local next_id=$(find_next_message_id "$current_id")
                if [ -n "$next_id" ]; then
                    echo "Opening next message: $next_id"
                    process_message "$next_id"
                else
                    echo "No more messages. Exiting."
                    exit 0
                fi
            else
                echo "Failed to delete message $current_id."
                echo "Press any key to continue..."
                read_char > /dev/null
                process_message "$current_id"
            fi
            ;;
        a|A)
            echo "Archiving message $current_id..."
            if himalaya message move Archives "$current_id"; then
                echo "Message $current_id archived successfully."
                refresh_vim_himalaya
                # Try to open next available message
                local next_id=$(find_next_message_id "$current_id")
                if [ -n "$next_id" ]; then
                    echo "Opening next message: $next_id"
                    process_message "$next_id"
                else
                    echo "No more messages. Exiting."
                    exit 0
                fi
            else
                echo "Failed to archive message $current_id."
                echo "Press any key to continue..."
                read_char > /dev/null
                process_message "$current_id"
            fi
            ;;
        n|N)
            local next_id=$(find_next_message_id "$current_id")
            if [ -n "$next_id" ]; then
                echo "Opening next message: $next_id"
                process_message "$next_id"
            else
                echo "No next message available."
                echo "Press any key to continue..."
                read_char > /dev/null
                process_message "$current_id"
            fi
            ;;
        p|P)
            local prev_id=$(find_previous_message_id "$current_id")
            if [ -n "$prev_id" ]; then
                echo "Opening previous message: $prev_id"
                process_message "$prev_id"
            else
                echo "No previous message available."
                echo "Press any key to continue..."
                read_char > /dev/null
                process_message "$current_id"
            fi
            ;;
        r|R)
            echo "Reopening message $current_id..."
            process_message "$current_id"
            ;;
        q|Q)
            echo "Exiting."
            exit 0
            ;;
        *)
            echo "Invalid choice. Please try again."
            echo "Press any key to continue..."
            read_char > /dev/null
            process_message "$current_id"
            ;;
    esac
}

# Function to process a message (read and show menu)
process_message() {
    local message_id="$1"
    local is_fallback="$2"
    
    echo "Reading message $message_id..."
    if run_himalaya_message_read "$message_id"; then
        show_action_menu "$message_id"
    else
        echo "Error reading message $message_id."
        if [ "$is_fallback" = "true" ]; then
            # If this was already a fallback attempt, don't try again
            echo "Unable to read any messages. Exiting."
            exit 1
        else
            # Try to find a valid message to fall back to
            echo "Trying to find an available message..."
            local latest_id=$(get_latest_message_id)
            if [ -n "$latest_id" ] && [ "$latest_id" != "$message_id" ]; then
                echo "Opening latest message: $latest_id"
                process_message "$latest_id" "true"
            else
                echo "No valid messages found. Exiting."
                exit 1
            fi
        fi
    fi
}

# Main script logic

# Check if message ID is provided, otherwise get the latest
if [ -z "$1" ]; then
    echo "No message ID provided. Finding latest message..."
    message_id=$(get_latest_message_id)
    if [ -z "$message_id" ]; then
        echo "No messages found in inbox."
        exit 1
    fi
    echo "Latest message ID: $message_id"
else
    message_id="$1"
fi

# Validate that himalaya is available
if ! command -v himalaya >/dev/null 2>&1; then
    echo "Error: himalaya command not found. Please install himalaya."
    exit 1
fi

# Start processing the message
process_message "$message_id"