-- Island Miner v0.2.0
-- A turtle program that mines gravel and andesite around an island
-- This program requires a turtle with a pickaxe

-- Constants
local VERSION = "0.2.0"
local STARTING_POSITION = {x = -279, y = 64, z = -182}
local MAX_Y_LEVEL = 70
local REFUEL_THRESHOLD = 50 -- Refuel when fuel level drops below this value
local TARGET_BLOCKS = {
    ["minecraft:gravel"] = true,
    ["minecraft:andesite"] = true
}

-- Debug logging function
local function log(message)
    print("[DEBUG] " .. message)
end

-- Current position and orientation
local position = {
    x = STARTING_POSITION.x,
    y = STARTING_POSITION.y,
    z = STARTING_POSITION.z
}
local facing = 0 -- 0 = north, 1 = east, 2 = south, 3 = west

-- Function to check if a block is a target block
local function isTargetBlock()
    local success, data = turtle.inspect()
    if success then
        -- Log the block type we found
        log("Found block: " .. data.name)

        -- Check if it's in our target list
        local isTarget = TARGET_BLOCKS[data.name] == true

        if not isTarget then
            log("Block is not a target block, skipping")
        end

        return isTarget
    end
    return false
end

-- Function to check if a block is exposed to air
local function isExposedToAir()
    -- Check if we can move up first before trying to move up
    if turtle.detectUp() then
        log("Block above is not air, can't check if target is exposed to air")
        return false
    end

    -- Move up to check if the block above is air
    turtle.up()
    position.y = position.y + 1

    -- Look down to check the block below
    turtle.turnLeft()
    turtle.turnLeft()
    facing = (facing + 2) % 4

    local success, data = turtle.inspect()
    local isAir = not success

    if success then
        isAir = data.name == "minecraft:air"
        log("Block above target is: " .. data.name .. ", isAir: " .. tostring(isAir))
    else
        log("No block detected above target, treating as air")
    end

    -- Return to original position and orientation
    turtle.turnLeft()
    turtle.turnLeft()
    facing = (facing + 2) % 4
    turtle.down()
    position.y = position.y - 1

    return isAir
end

-- Function to refuel if needed
local function refuelIfNeeded()
    local fuelLevel = turtle.getFuelLevel()

    if fuelLevel < REFUEL_THRESHOLD then
        print("Fuel low (" .. fuelLevel .. "), attempting to refuel...")

        -- Try each inventory slot for fuel
        for i = 1, 16 do
            turtle.select(i)
            if turtle.refuel(0) then
                local before = turtle.getFuelLevel()
                turtle.refuel(1)
                local after = turtle.getFuelLevel()
                print("Refueled with " .. (after - before) .. " fuel units")
                if turtle.getFuelLevel() >= REFUEL_THRESHOLD then
                    break
                end
            end
        end

        -- Check if refueling was successful
        if turtle.getFuelLevel() < REFUEL_THRESHOLD then
            print("WARNING: Unable to refuel to threshold. Current fuel: " .. turtle.getFuelLevel())
        end
    end
end

-- Movement functions that update position
local function forward()
    refuelIfNeeded()
    if turtle.forward() then
        if facing == 0 then position.z = position.z - 1      -- North
        elseif facing == 1 then position.x = position.x + 1  -- East
        elseif facing == 2 then position.z = position.z + 1  -- South
        elseif facing == 3 then position.x = position.x - 1  -- West
        end
        return true
    end
    return false
end

local function up()
    refuelIfNeeded()
    if position.y < MAX_Y_LEVEL and turtle.up() then
        position.y = position.y + 1
        return true
    end
    return false
end

local function down()
    refuelIfNeeded()
    if turtle.down() then
        position.y = position.y - 1
        return true
    end
    return false
end

local function turnLeft()
    turtle.turnLeft()
    facing = (facing - 1) % 4
end

local function turnRight()
    turtle.turnRight()
    facing = (facing + 1) % 4
end

-- Function to check and mine target blocks
local function checkAndMine()
    -- Only check if it's exposed to air if it's a target block
    if isTargetBlock() then
        if isExposedToAir() then
            print("Mining " .. position.x .. "," .. position.y .. "," .. position.z)
            turtle.dig()
            return true
        else
            log("Block not exposed to air, skipping")
        end
    end
    return false
end

-- Spiral search pattern to find and mine blocks
local function spiralSearch(maxRadius)
    local radius = 1
    local direction = 0  -- 0 = north, 1 = east, 2 = south, 3 = west
    local steps = 1

    while radius <= maxRadius do
        for i = 1, 2 do
            for j = 1, steps do
                checkAndMine()

                -- Check blocks in other directions
                turnLeft()
                checkAndMine()
                turnRight()

                turnRight()
                checkAndMine()
                turnLeft()

                -- Move forward, but try not to dig if it's not a target block
                if not forward() then
                    -- Check if it's a target block before digging
                    if isTargetBlock() then
                        log("Target block in path, digging to move forward")
                        turtle.dig()
                    else
                        -- Try to go around the obstacle
                        log("Non-target block in path, trying to go around")
                        -- Try going up and over
                        if position.y < MAX_Y_LEVEL - 1 and up() then
                            forward()
                            down()
                        else
                            -- If we can't go over, try going around
                            turnLeft()
                            if forward() then
                                turnRight()
                                forward()
                                turnRight()
                                forward()
                                turnLeft()
                            else
                                turnRight()
                                turnRight()
                                if forward() then
                                    turnLeft()
                                    forward()
                                    turnLeft()
                                    forward()
                                    turnRight()
                                else
                                    -- If we can't go around, just dig through as a last resort
                                    turnRight()
                                    log("Unable to navigate around obstacle, digging through")
                                    turtle.dig()
                                    if not forward() then
                                        print("Path completely blocked at " .. position.x .. "," .. position.y .. "," .. position.z)
                                    end
                                end
                            end
                        end
                    end
                end
            end

            -- Change direction
            turnLeft()
            direction = (direction + 1) % 4
        end

        steps = steps + 1
        radius = radius + 1
    end
end

-- Main function to search at different y levels
local function searchArea()
    print("Island Miner v" .. VERSION)
    print("Starting at position: " .. position.x .. "," .. position.y .. "," .. position.z)

    -- Start at the initial position
    for y = position.y, MAX_Y_LEVEL - 1 do
        print("Searching at y level: " .. position.y)
        spiralSearch(20)  -- Search in a spiral pattern with max radius of 20 blocks

        -- Move up to the next level if not at max height
        if position.y < MAX_Y_LEVEL - 1 then
            up()
        end
    end

    -- Return to starting position
    print("Mining complete, returning to start position")

    -- Navigate back to starting coordinates
    while position.y > STARTING_POSITION.y do
        down()
    end

    print("Mining operation completed")
end

-- Run the program
searchArea()