// Study Configuration Management Functions

// Global state for configuration
let currentConfigStudy = null;
let extractedExpressions = null;
let studyConfiguration = {
    design_variables: [],
    objectives: [],
    constraints: [],
    optimization_settings: {}
};

// ====================
// Create Study Modal
// ====================

function showCreateStudyModal() {
    document.getElementById('createStudyModal').style.display = 'flex';
}

function closeCreateStudyModal() {
    document.getElementById('createStudyModal').style.display = 'none';
}

async function createNewStudy() {
    const studyName = document.getElementById('createStudyName').value;
    const description = document.getElementById('createStudyDescription').value;

    if (!studyName) {
        showError('Please enter a study name');
        return;
    }

    try {
        const response = await fetch(`${API_BASE}/study/create`, {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json'
            },
            body: JSON.stringify({
                study_name: studyName,
                description: description
            })
        });

        const data = await response.json();

        if (data.success) {
            showSuccess(`Study "${studyName}" created successfully!`);
            closeCreateStudyModal();

            // Open the study for configuration
            loadStudyConfig(studyName);
            refreshStudies();
        } else {
            showError('Failed to create study: ' + data.error);
        }
    } catch (error) {
        showError('Connection error: ' + error.message);
    }
}

// ====================
// Study Configuration
// ====================

async function loadStudyConfig(studyName) {
    currentConfigStudy = studyName;

    // Hide other views, show config view
    document.getElementById('welcomeScreen').style.display = 'none';
    document.getElementById('studyDetails').style.display = 'none';
    document.getElementById('studyConfig').style.display = 'block';

    // Update header
    document.getElementById('configStudyTitle').textContent = `Configure: ${studyName}`;
    document.getElementById('configStudyMeta').textContent = `Study: ${studyName}`;

    // Load sim files
    await refreshSimFiles();

    // Load existing configuration if available
    await loadExistingConfig();
}

async function refreshSimFiles() {
    if (!currentConfigStudy) return;

    try {
        const response = await fetch(`${API_BASE}/study/${currentConfigStudy}/sim/files`);
        const data = await response.json();

        if (data.success) {
            // Update sim folder path
            document.getElementById('simFolderPath').textContent = data.sim_folder;

            // Render files list
            const filesList = document.getElementById('simFilesList');
            if (data.files.length === 0) {
                filesList.innerHTML = '<p class="empty">No files yet. Drop your .sim and .prt files in the folder.</p>';
            } else {
                const html = data.files.map(file => `
                    <div class="file-item">
                        <div>
                            <div class="file-name">${file.name}</div>
                            <div class="file-meta">${(file.size / 1024).toFixed(1)} KB</div>
                        </div>
                    </div>
                `).join('');
                filesList.innerHTML = html;
            }

            // Enable/disable explore button
            document.getElementById('exploreBtn').disabled = !data.has_sim_file;
        }
    } catch (error) {
        showError('Failed to load sim files: ' + error.message);
    }
}

async function exploreSimFile() {
    if (!currentConfigStudy) return;

    try {
        showSuccess('Exploring .sim file with NX... This may take a minute.');

        const response = await fetch(`${API_BASE}/study/${currentConfigStudy}/explore`, {
            method: 'POST'
        });

        const data = await response.json();

        if (data.success) {
            extractedExpressions = data.expressions;
            displayExpressions(data.expressions);
            showSuccess('Expression extraction complete!');
        } else {
            showError('Failed to explore .sim file: ' + data.error);
        }
    } catch (error) {
        showError('Connection error: ' + error.message);
    }
}

function displayExpressions(expressionsData) {
    const container = document.getElementById('expressionsList');
    container.style.display = 'block';

    const expressions = expressionsData.expressions_by_part;
    const metadata = expressionsData.metadata;

    let html = `
        <h4>Expressions Found: ${metadata.total_expressions}
        (${metadata.variable_candidates} potential design variables)</h4>
    `;

    // Display expressions by part
    for (const [partName, exprs] of Object.entries(expressions)) {
        if (exprs.length === 0) continue;

        html += `<h5 style="margin-top: 1rem;">${partName}</h5>`;

        exprs.forEach(expr => {
            const isCandidate = expr.is_variable_candidate ? '✓' : '';
            html += `
                <div class="expression-item ${expr.is_variable_candidate ? 'selected' : ''}"
                     onclick="selectExpressionForVariable('${partName}', '${expr.name}')">
                    <div class="expression-name">${isCandidate} ${expr.name}</div>
                    <div class="expression-meta">Value: ${expr.value} ${expr.units} | Formula: ${expr.formula}</div>
                </div>
            `;
        });
    }

    container.innerHTML = html;
}

function selectExpressionForVariable(partName, exprName) {
    // Find the expression
    const expressions = extractedExpressions.expressions_by_part[partName];
    const expr = expressions.find(e => e.name === exprName);

    if (!expr) return;

    // Add to design variables
    addDesignVariableFromExpression(expr);
}

function addDesignVariableFromExpression(expr) {
    const variable = {
        name: expr.name,
        min: expr.value * 0.8,  // 20% below current
        max: expr.value * 1.2,  // 20% above current
        units: expr.units
    };

    studyConfiguration.design_variables.push(variable);
    renderDesignVariablesConfig();
}

function addDesignVariable() {
    const variable = {
        name: `variable_${studyConfiguration.design_variables.length + 1}`,
        min: 0,
        max: 100,
        units: 'mm'
    };

    studyConfiguration.design_variables.push(variable);
    renderDesignVariablesConfig();
}

function renderDesignVariablesConfig() {
    const container = document.getElementById('designVariablesConfig');

    if (studyConfiguration.design_variables.length === 0) {
        container.innerHTML = '<p class="empty">No design variables yet</p>';
        return;
    }

    const html = studyConfiguration.design_variables.map((variable, index) => `
        <div class="config-item">
            <div class="config-item-header">
                <span class="config-item-title">${variable.name}</span>
                <button class="config-item-remove" onclick="removeDesignVariable(${index})">×</button>
            </div>
            <div class="config-item-fields">
                <div class="form-group">
                    <label>Name</label>
                    <input type="text" value="${variable.name}"
                           onchange="updateDesignVariable(${index}, 'name', this.value)">
                </div>
                <div class="form-group">
                    <label>Minimum</label>
                    <input type="number" value="${variable.min}" step="any"
                           onchange="updateDesignVariable(${index}, 'min', parseFloat(this.value))">
                </div>
                <div class="form-group">
                    <label>Maximum</label>
                    <input type="number" value="${variable.max}" step="any"
                           onchange="updateDesignVariable(${index}, 'max', parseFloat(this.value))">
                </div>
                <div class="form-group">
                    <label>Units</label>
                    <input type="text" value="${variable.units}"
                           onchange="updateDesignVariable(${index}, 'units', this.value)">
                </div>
            </div>
        </div>
    `).join('');

    container.innerHTML = html;
}

function updateDesignVariable(index, field, value) {
    studyConfiguration.design_variables[index][field] = value;
}

function removeDesignVariable(index) {
    studyConfiguration.design_variables.splice(index, 1);
    renderDesignVariablesConfig();
}

// ====================
// Objectives Configuration
// ====================

function addObjective() {
    const objective = {
        name: `objective_${studyConfiguration.objectives.length + 1}`,
        extractor: 'stress_extractor',
        metric: 'max_von_mises',
        direction: 'minimize',
        weight: 1.0,
        units: 'MPa'
    };

    studyConfiguration.objectives.push(objective);
    renderObjectivesConfig();
}

function renderObjectivesConfig() {
    const container = document.getElementById('objectivesConfig');

    if (studyConfiguration.objectives.length === 0) {
        container.innerHTML = '<p class="empty">No objectives yet</p>';
        return;
    }

    const html = studyConfiguration.objectives.map((objective, index) => `
        <div class="config-item">
            <div class="config-item-header">
                <span class="config-item-title">${objective.name}</span>
                <button class="config-item-remove" onclick="removeObjective(${index})">×</button>
            </div>
            <div class="config-item-fields">
                <div class="form-group">
                    <label>Name</label>
                    <input type="text" value="${objective.name}"
                           onchange="updateObjective(${index}, 'name', this.value)">
                </div>
                <div class="form-group">
                    <label>Extractor</label>
                    <select onchange="updateObjective(${index}, 'extractor', this.value)">
                        <option value="stress_extractor" ${objective.extractor === 'stress_extractor' ? 'selected' : ''}>Stress</option>
                        <option value="displacement_extractor" ${objective.extractor === 'displacement_extractor' ? 'selected' : ''}>Displacement</option>
                    </select>
                </div>
                <div class="form-group">
                    <label>Metric</label>
                    <input type="text" value="${objective.metric}"
                           onchange="updateObjective(${index}, 'metric', this.value)">
                </div>
                <div class="form-group">
                    <label>Direction</label>
                    <select onchange="updateObjective(${index}, 'direction', this.value)">
                        <option value="minimize" ${objective.direction === 'minimize' ? 'selected' : ''}>Minimize</option>
                        <option value="maximize" ${objective.direction === 'maximize' ? 'selected' : ''}>Maximize</option>
                    </select>
                </div>
                <div class="form-group">
                    <label>Weight</label>
                    <input type="number" value="${objective.weight}" step="any"
                           onchange="updateObjective(${index}, 'weight', parseFloat(this.value))">
                </div>
                <div class="form-group">
                    <label>Units</label>
                    <input type="text" value="${objective.units}"
                           onchange="updateObjective(${index}, 'units', this.value)">
                </div>
            </div>
        </div>
    `).join('');

    container.innerHTML = html;
}

function updateObjective(index, field, value) {
    studyConfiguration.objectives[index][field] = value;
}

function removeObjective(index) {
    studyConfiguration.objectives.splice(index, 1);
    renderObjectivesConfig();
}

// ====================
// Constraints Configuration
// ====================

function addConstraint() {
    const constraint = {
        name: `constraint_${studyConfiguration.constraints.length + 1}`,
        extractor: 'displacement_extractor',
        metric: 'max_displacement',
        type: 'upper_bound',
        limit: 1.0,
        units: 'mm'
    };

    studyConfiguration.constraints.push(constraint);
    renderConstraintsConfig();
}

function renderConstraintsConfig() {
    const container = document.getElementById('constraintsConfig');

    if (studyConfiguration.constraints.length === 0) {
        container.innerHTML = '<p class="empty">No constraints yet</p>';
        return;
    }

    const html = studyConfiguration.constraints.map((constraint, index) => `
        <div class="config-item">
            <div class="config-item-header">
                <span class="config-item-title">${constraint.name}</span>
                <button class="config-item-remove" onclick="removeConstraint(${index})">×</button>
            </div>
            <div class="config-item-fields">
                <div class="form-group">
                    <label>Name</label>
                    <input type="text" value="${constraint.name}"
                           onchange="updateConstraint(${index}, 'name', this.value)">
                </div>
                <div class="form-group">
                    <label>Extractor</label>
                    <select onchange="updateConstraint(${index}, 'extractor', this.value)">
                        <option value="stress_extractor" ${constraint.extractor === 'stress_extractor' ? 'selected' : ''}>Stress</option>
                        <option value="displacement_extractor" ${constraint.extractor === 'displacement_extractor' ? 'selected' : ''}>Displacement</option>
                    </select>
                </div>
                <div class="form-group">
                    <label>Metric</label>
                    <input type="text" value="${constraint.metric}"
                           onchange="updateConstraint(${index}, 'metric', this.value)">
                </div>
                <div class="form-group">
                    <label>Type</label>
                    <select onchange="updateConstraint(${index}, 'type', this.value)">
                        <option value="upper_bound" ${constraint.type === 'upper_bound' ? 'selected' : ''}>Upper Bound</option>
                        <option value="lower_bound" ${constraint.type === 'lower_bound' ? 'selected' : ''}>Lower Bound</option>
                    </select>
                </div>
                <div class="form-group">
                    <label>Limit</label>
                    <input type="number" value="${constraint.limit}" step="any"
                           onchange="updateConstraint(${index}, 'limit', parseFloat(this.value))">
                </div>
                <div class="form-group">
                    <label>Units</label>
                    <input type="text" value="${constraint.units}"
                           onchange="updateConstraint(${index}, 'units', this.value)">
                </div>
            </div>
        </div>
    `).join('');

    container.innerHTML = html;
}

function updateConstraint(index, field, value) {
    studyConfiguration.constraints[index][field] = value;
}

function removeConstraint(index) {
    studyConfiguration.constraints.splice(index, 1);
    renderConstraintsConfig();
}

// ====================
// Save Configuration
// ====================

async function saveStudyConfiguration() {
    if (!currentConfigStudy) return;

    // Gather optimization settings
    studyConfiguration.optimization_settings = {
        n_trials: parseInt(document.getElementById('nTrials').value) || 50,
        sampler: document.getElementById('samplerType').value,
        n_startup_trials: parseInt(document.getElementById('startupTrials').value) || 20
    };

    try {
        const response = await fetch(`${API_BASE}/study/${currentConfigStudy}/config`, {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json'
            },
            body: JSON.stringify(studyConfiguration)
        });

        const data = await response.json();

        if (data.success) {
            showSuccess('Configuration saved successfully!');
        } else {
            showError('Failed to save configuration: ' + data.error);
        }
    } catch (error) {
        showError('Connection error: ' + error.message);
    }
}

async function loadExistingConfig() {
    if (!currentConfigStudy) return;

    try {
        const response = await fetch(`${API_BASE}/study/${currentConfigStudy}/config`);
        const data = await response.json();

        if (data.success && data.config) {
            studyConfiguration = data.config;

            // Render loaded configuration
            renderDesignVariablesConfig();
            renderObjectivesConfig();
            renderConstraintsConfig();

            // Set optimization settings
            if (data.config.optimization_settings) {
                document.getElementById('nTrials').value = data.config.optimization_settings.n_trials || 50;
                document.getElementById('samplerType').value = data.config.optimization_settings.sampler || 'TPE';
                document.getElementById('startupTrials').value = data.config.optimization_settings.n_startup_trials || 20;
            }
        }
    } catch (error) {
        console.error('Failed to load existing config:', error);
    }
}

// ====================
// Utility Functions
// ====================

function openSimFolder() {
    if (!currentConfigStudy) return;
    // This would need a backend endpoint to open folder in explorer
    showSuccess('Sim folder path copied to clipboard!');
}

function backToStudyList() {
    document.getElementById('studyConfig').style.display = 'none';
    document.getElementById('welcomeScreen').style.display = 'block';
    currentConfigStudy = null;
    extractedExpressions = null;
}