// Initialize the chart
const chartDom = document.getElementById('chart-container');
const myChart = echarts.init(chartDom);
let option;

// Function to parse CSV data
async function parseCSV(file) {
    const response = await fetch(file);
    const data = await response.text();
    
    // Split the CSV into rows
    const rows = data.split('\n');
    
    // Extract headers and remove quotes
    const headers = rows[0].split(',').map(header => header.replace(/"/g, ''));
    
    // Parse the data rows
    const result = [];
    for (let i = 1; i < rows.length; i++) {
        if (!rows[i].trim()) continue;
        
        // Handle commas within quoted fields
        const row = [];
        let inQuote = false;
        let currentValue = '';
        
        for (let j = 0; j < rows[i].length; j++) {
            const char = rows[i][j];
            
            if (char === '"') {
                inQuote = !inQuote;
            } else if (char === ',' && !inQuote) {
                row.push(currentValue.replace(/"/g, ''));
                currentValue = '';
            } else {
                currentValue += char;
            }
        }
        
        // Push the last value
        row.push(currentValue.replace(/"/g, ''));
        
        // Create an object from headers and row values
        const obj = {};
        for (let j = 0; j < headers.length; j++) {
            obj[headers[j]] = row[j];
        }
        
        result.push(obj);
    }
    
    return result;
}

// Function to transform data into a sunburst format
function transformToSunburst(data) {
    // Calculate total spending
    let totalSpending = 0;
    
    // Group by categories
    const categories = [];
    const categoryMap = {};
    
    // Predefined colors for categories
    const colors = [
        '#5470c6', '#91cc75', '#fac858', '#ee6666', '#73c0de',
        '#3ba272', '#fc8452', '#9a60b4', '#ea7ccc', '#4cae72',
        '#d56358', '#82b1ff', '#f19143', '#addf84', '#6f7787'
    ];
    
    data.forEach(item => {
        const category = item.category || '';
        const subcategory = item.subcategory || '';
        const microcategory = item.microcategory || '';
        const amount = Math.abs(parseFloat(item.amount_rub));
        
        if (!isNaN(amount)) {
            totalSpending += amount;
            
            if (!categoryMap[category] && category !== '') {
                categoryMap[category] = {
                    name: category,
                    value: 0,
                    children: {},
                    itemStyle: {}
                };
                categories.push(categoryMap[category]);
            }
            
            if (category !== '') {
                if (!categoryMap[category].children[subcategory] && subcategory !== '') {
                    categoryMap[category].children[subcategory] = {
                        name: subcategory,
                        value: 0,
                        children: {},
                        itemStyle: {}
                    };
                }
                
                if (subcategory !== '') {
                    if (!categoryMap[category].children[subcategory].children[microcategory] && microcategory !== '') {
                        categoryMap[category].children[subcategory].children[microcategory] = {
                            name: microcategory,
                            value: 0,
                            itemStyle: {}
                        };
                    }
                    
                    categoryMap[category].value += amount;
                    categoryMap[category].children[subcategory].value += amount;
                    
                    if (microcategory !== '') {
                        categoryMap[category].children[subcategory].children[microcategory].value += amount;
                    }
                } else {
                    categoryMap[category].value += amount;
                }
            }
        }
    });
    
    // Convert the map to an array structure for ECharts
    const result = [];
    
    // Assign colors to categories
    categories.forEach((category, index) => {
        const colorIndex = index % colors.length;
        const categoryNode = {
            name: category.name,
            value: category.value,
            children: [],
            itemStyle: {
                color: colors[colorIndex]
            }
        };
        
        const subcategories = [];
        for (const subcatKey in category.children) {
            subcategories.push(category.children[subcatKey]);
        }
        
        subcategories.forEach(subcategory => {
            const subcategoryNode = {
                name: subcategory.name,
                value: subcategory.value,
                children: [],
                itemStyle: {
                    color: colors[colorIndex]
                }
            };
            
            const microcategories = [];
            for (const microKey in subcategory.children) {
                microcategories.push(subcategory.children[microKey]);
            }
            
            microcategories.forEach(micro => {
                subcategoryNode.children.push({
                    name: micro.name,
                    value: micro.value,
                    itemStyle: {
                        color: colors[colorIndex]
                    }
                });
            });
            
            if (subcategoryNode.children.length > 0) {
                categoryNode.children.push(subcategoryNode);
            } else {
                categoryNode.children.push({
                    name: subcategory.name,
                    value: subcategory.value,
                    itemStyle: {
                        color: colors[colorIndex]
                    }
                });
            }
        });
        
        result.push(categoryNode);
    });
    
    return {
        total: totalSpending,
        data: result
    };
}

// Function to render the chart
function renderChart(data) {
    const sunburstData = transformToSunburst(data);
    
    option = {
        backgroundColor: '#fff',
        grid: {
            left: '10%', // Move chart to the left
            containLabel: true
        },
        series: {
            type: 'sunburst',
            radius: [0, '95%'],
            center: ['40%', '50%'], // Move chart to the left
            nodeClick: 'rootToNode', // To enable drill down on click
            data: sunburstData.data,
            label: {
                show: true,
                formatter: function(param) {
                    if (param.depth === 0) {
                        // Add line breaks for long category names
                        if (param.name.length > 10) {
                            return param.name.replace(/(.{1,10})(?: |$)/g, "$1\n").trim();
                        }
                        return param.name;
                    } else {
                        return '';
                    }
                },
                minAngle: 5,
                align: 'center',
                verticalAlign: 'middle',
                position: 'inside'
            },
            itemStyle: {
                borderWidth: 1,
                borderColor: '#fff'
            },
            levels: [
                {},
                {
                    // First level - Categories
                    r0: '20%',
                    r: '45%',
                    label: {
                        show: true,
                        rotate: 'radial',
                        fontSize: 12,
                        lineHeight: 15,
                        verticalAlign: 'center',
                        position: 'inside',
                    },
                    itemStyle: {
                        borderWidth: 2
                    }

                },
                {
                    // Second level - Subcategories
                    r0: '45%',
                    r: '70%',
                    label: {
                        show: false,
                        fontSize: 11,
                        align: 'left',
                        position: 'inside',
                        distance: 5,

                    },
                    itemStyle: {
                        borderWidth: 1
                    },
                    emphasis: {
                        label: {
                            show: true,
                            distance: 20,
                        }
                    }
                },
                {
                    // Third level - Microcategories - a bit wider than before
                    r0: '70%',
                    r: '75%',
                    label: {
                        show: false,
                        position: 'outside',
                        padding: 3,
                        silent: false,
                        fontSize: 10,
                        formatter: function(param) {
                            if (param.name.length > 10) {
                                return param.name.slice(0, 8) + '...';
                            }
                            return param.name;
                        }
                    },
                    itemStyle: {
                        borderWidth: 3
                    }
                }
            ],
            emphasis: {
                focus: 'relative',
            },
            // Add more space between wedges
            gap: 2,
            // Allow the chart to sort segments by value
            sort: null,
            tooltip: {
                trigger: 'item',
                formatter: function(info) {
                    const value = info.value.toLocaleString();
                    const name = info.name;
                    
                    // Calculate percentage of total
                    const percentage = ((info.value / sunburstData.total) * 100).toFixed(1);
                    
                    return `${name}<br/>Amount: ${value} RUB<br/>Percentage: ${percentage}%`;
                }
            }
        },
        graphic: [
            {
                type: 'text',
                left: '37%', // Align with new center position
                top: '49%',
                style: {
                    text: sunburstData.total.toFixed(0).toLocaleString()+" ₽",
                    fontWeight: 'bold',
                    fontSize: 18,
                    textAlign: 'center',
                    textVerticalAlign: 'middle',
                    position: 'center',
                    width: 20,
                    height: 40
                },
                z: 100 // Ensure it's on top
            }
           
        ]
    };
    
    // Handle chart events - recolor on drill down
    myChart.off('click');
    myChart.on('click', function(params) {
        if (params.depth >= 0) { // Handle clicks on any level, not just depth 0
            const colorPalette = [
                '#5470c6', '#91cc75', '#fac858', '#ee6666', '#73c0de',
                '#3ba272', '#fc8452', '#9a60b4', '#ea7ccc', '#4cae72'
            ];
            
            // Clone the data to modify it
            const currentData = JSON.parse(JSON.stringify(option.series.data));
            
            // Find the path to the clicked item
            let targetData;
            let categoryIndex = -1;
            
            if (params.depth === 0) {
                // If clicking on a top-level category
                categoryIndex = currentData.findIndex(item => item.name === params.name);
                if (categoryIndex !== -1) {
                    targetData = currentData[categoryIndex];
                }
            } else if (params.depth === 1) {
                // If clicking on a subcategory, find its parent category first
                for (let i = 0; i < currentData.length; i++) {
                    if (currentData[i].children) {
                        const subIndex = currentData[i].children.findIndex(sub => sub.name === params.name);
                        if (subIndex !== -1) {
                            targetData = currentData[i].children[subIndex];
                            categoryIndex = i;
                            break;
                        }
                    }
                }
            }
            
            if (targetData && targetData.children && targetData.children.length > 0) {
                // Recolor children with unique colors
                targetData.children.forEach((child, i) => {
                    const color = colorPalette[i % colorPalette.length];
                    child.itemStyle = {
                        color: color
                    };
                    
                    // If the child has children (microcategories), color them too
                    if (child.children && child.children.length > 0) {
                        const microColors = generateColorGradient(color, child.children.length);
                        child.children.forEach((micro, j) => {
                            micro.itemStyle = {
                                color: microColors[j]
                            };
                        });
                    }
                });
                
                // Update the chart with modified data
                if (params.depth === 0) {
                    currentData[categoryIndex] = targetData;
                } else if (params.depth === 1) {
                    // Update the subcategory within its parent category
                    for (let i = 0; i < currentData[categoryIndex].children.length; i++) {
                        if (currentData[categoryIndex].children[i].name === params.name) {
                            currentData[categoryIndex].children[i] = targetData;
                            break;
                        }
                    }
                }
                
                option.series.data = currentData;
                myChart.setOption(option, { replaceMerge: ['series'] });
            }
        }
    });
    
    myChart.setOption(option);
    
    // Set up hover events for the details box
    setupHoverEvents();
}

// Function to generate a color gradient
function generateColorGradient(baseColor, steps) {
    const result = [];
    const base = tinycolor(baseColor);
    
    // Generate lighter shades for better contrast
    for (let i = 0; i < steps; i++) {
        // Create various tints and shades based on the position
        let color;
        if (i % 3 === 0) {
            color = base.clone().lighten(15);
        } else if (i % 3 === 1) {
            color = base.clone().darken(10);
        } else {
            color = base.clone().saturate(20);
        }
        result.push(color.toString());
    }
    
    return result;
}

// Load TinyColor library for color manipulation
function loadTinyColor() {
    return new Promise((resolve, reject) => {
        if (window.tinycolor) {
            resolve();
            return;
        }
        
        const script = document.createElement('script');
        script.src = 'https://cdnjs.cloudflare.com/ajax/libs/tinycolor/1.4.2/tinycolor.min.js';
        script.onload = resolve;
        script.onerror = reject;
        document.head.appendChild(script);
    });
}

// Load all available month files
async function loadAvailableMonths() {
    // Load TinyColor first
    await loadTinyColor();
    
    // For now, we only have one month
    const months = ['2025-01'];
    const select = document.getElementById('month-select');
    
    months.forEach(month => {
        const option = document.createElement('option');
        option.value = month;
        option.textContent = month;
        select.appendChild(option);
    });
    
    // Load the first month by default
    const data = await parseCSV(`altcats-${months[0]}.csv`);
    renderChart(data);
    
    // Add event listener for month selection
    select.addEventListener('change', async (e) => {
        const month = e.target.value;
        const data = await parseCSV(`altcats-${month}.csv`);
        renderChart(data);
    });
}

// Initialize the visualization
loadAvailableMonths();

// Handle window resize
window.addEventListener('resize', function() {
    myChart.resize();
});

// Add mouseover handler to update details box
function setupHoverEvents() {
    const hoverNameElement = document.getElementById('hover-name');
    const hoverAmountElement = document.getElementById('hover-amount');
    const topItemsElement = document.getElementById('top-items');
    
    // Add mouseover event listener
    myChart.on('mouseover', function(params) {
        // Only process data nodes, not empty areas
        if (params.data) {
            // Set the name and amount
            hoverNameElement.textContent = params.name;
            hoverAmountElement.textContent = params.value.toLocaleString() + ' RUB';
            
            // Clear previous top items
            topItemsElement.innerHTML = '';
            
            // Find top items if there are children
            if (params.data.children && params.data.children.length > 0) {
                // Sort children by value
                const sortedChildren = [...params.data.children].sort((a, b) => b.value - a.value);
                
                // Display top 10 or fewer
                const topChildren = sortedChildren.slice(0, 10);
                
                // Create elements for each top item
                topChildren.forEach(child => {
                    const itemDiv = document.createElement('div');
                    itemDiv.className = 'top-item';
                    
                    const nameSpan = document.createElement('span');
                    nameSpan.className = 'top-item-name';
                    nameSpan.textContent = child.name;
                    itemDiv.appendChild(nameSpan);
                    
                    const amountSpan = document.createElement('span');
                    amountSpan.className = 'top-item-amount';
                    amountSpan.textContent = child.value.toLocaleString() + ' ₽';
                    itemDiv.appendChild(amountSpan);
                    
                    // Add percentage
                    const percentage = ((child.value / params.value) * 100).toFixed(1);
                    amountSpan.textContent += ` (${percentage}%)`;
                    
                    topItemsElement.appendChild(itemDiv);
                });
            } else {
                // No children, show a message
                topItemsElement.innerHTML = '<div>No subcategories available</div>';
            }
        }
    });
    
    // Reset on mouseout from the chart
    myChart.on('mouseout', function(params) {
        if (!params.data) {
            hoverNameElement.textContent = 'Hover over a segment to see details';
            hoverAmountElement.textContent = '';
            topItemsElement.innerHTML = '';
        }
    });
}