//! Batch operations handler for bulk project management
//!
//! Supports batch create, update, delete, and phase transitions.

#![allow(dead_code)]

use anyhow::{anyhow, Result};
use serde::{Deserialize, Serialize};
use std::path::Path;

/// Batch operation types
#[derive(Debug, Clone, Copy, Eq, PartialEq, Serialize, Deserialize)]
pub enum BatchOperationType {
    /// Create multiple projects
    Create,
    /// Update multiple projects
    Update,
    /// Delete multiple projects
    Delete,
    /// Transition multiple projects to a phase
    Transition,
    /// Run security assessments on multiple projects
    Security,
}

/// Single project operation in a batch
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct BatchProjectOp {
    /// Project identifier or name
    pub project: String,
    /// Operation-specific data
    #[serde(default)]
    pub data: serde_json::Value,
}

/// Batch operation result
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct BatchResult {
    /// Project identifier
    pub project: String,
    /// Operation status
    pub success: bool,
    /// Status message
    pub message: String,
    /// Error details if failed
    #[serde(skip_serializing_if = "Option::is_none")]
    pub error: Option<String>,
}

/// Batch operation configuration loaded from TOML/JSON
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct BatchOperation {
    /// Operation type
    pub operation_type: String,
    /// Target phase (for transition operations)
    #[serde(default)]
    pub target_phase: Option<String>,
    /// Projects to operate on
    pub projects: Vec<BatchProjectOp>,
    /// Stop on first error
    #[serde(default = "default_stop_on_error")]
    pub stop_on_error: bool,
    /// Parallel execution (false = sequential)
    #[serde(default)]
    pub parallel: bool,
    /// Maximum parallel workers
    #[serde(default = "default_max_workers")]
    pub max_workers: usize,
}

fn default_stop_on_error() -> bool {
    true
}

fn default_max_workers() -> usize {
    4
}

/// Batch operations handler
pub struct BatchHandler;

impl BatchHandler {
    /// Load batch operation from TOML file
    pub fn load_from_file(path: impl AsRef<Path>) -> Result<BatchOperation> {
        let content = std::fs::read_to_string(path)?;
        let batch = toml::from_str(&content)?;
        Ok(batch)
    }

    /// Load batch operation from JSON file
    pub fn load_from_json(path: impl AsRef<Path>) -> Result<BatchOperation> {
        let content = std::fs::read_to_string(path)?;
        let batch = serde_json::from_str(&content)?;
        Ok(batch)
    }

    /// Execute batch operation
    pub fn execute(batch: &BatchOperation) -> Result<Vec<BatchResult>> {
        if batch.projects.is_empty() {
            return Err(anyhow!("No projects specified in batch operation"));
        }

        let results = if batch.parallel && batch.max_workers > 1 {
            Self::execute_parallel(batch)?
        } else {
            Self::execute_sequential(batch)?
        };

        Ok(results)
    }

    /// Execute batch operation sequentially
    fn execute_sequential(batch: &BatchOperation) -> Result<Vec<BatchResult>> {
        let mut results = Vec::new();

        for project_op in &batch.projects {
            let result = Self::execute_operation(batch, project_op);
            let batch_result = match result {
                Ok(msg) => BatchResult {
                    project: project_op.project.clone(),
                    success: true,
                    message: msg,
                    error: None,
                },
                Err(e) => {
                    let batch_result = BatchResult {
                        project: project_op.project.clone(),
                        success: false,
                        message: "Operation failed".to_string(),
                        error: Some(e.to_string()),
                    };

                    if batch.stop_on_error {
                        results.push(batch_result);
                        return Ok(results);
                    }

                    batch_result
                }
            };

            results.push(batch_result);
        }

        Ok(results)
    }

    /// Execute batch operation in parallel
    fn execute_parallel(batch: &BatchOperation) -> Result<Vec<BatchResult>> {
        let mut results = Vec::new();

        // For now, fall back to sequential execution
        // In production, this would use rayon or tokio for parallel execution
        for project_op in &batch.projects {
            let result = Self::execute_operation(batch, project_op);
            let batch_result = match result {
                Ok(msg) => BatchResult {
                    project: project_op.project.clone(),
                    success: true,
                    message: msg,
                    error: None,
                },
                Err(e) => BatchResult {
                    project: project_op.project.clone(),
                    success: false,
                    message: "Operation failed".to_string(),
                    error: Some(e.to_string()),
                },
            };

            results.push(batch_result);
        }

        Ok(results)
    }

    /// Execute single operation
    fn execute_operation(batch: &BatchOperation, project_op: &BatchProjectOp) -> Result<String> {
        match batch.operation_type.as_str() {
            "create" => Self::batch_create(project_op),
            "update" => Self::batch_update(project_op),
            "delete" => Self::batch_delete(project_op),
            "transition" => Self::batch_transition(batch, project_op),
            "security" => Self::batch_security(project_op),
            _ => Err(anyhow!("Unknown operation type: {}", batch.operation_type)),
        }
    }

    fn batch_create(project_op: &BatchProjectOp) -> Result<String> {
        // In production, this would call the actual project creation logic
        let name = project_op
            .data
            .get("name")
            .and_then(|v| v.as_str())
            .unwrap_or(&project_op.project);

        Ok(format!("Created project '{}'", name))
    }

    fn batch_update(project_op: &BatchProjectOp) -> Result<String> {
        // In production, this would call the actual project update logic
        Ok(format!("Updated project '{}'", project_op.project))
    }

    fn batch_delete(project_op: &BatchProjectOp) -> Result<String> {
        // In production, this would call the actual project deletion logic
        Ok(format!("Deleted project '{}'", project_op.project))
    }

    fn batch_transition(batch: &BatchOperation, project_op: &BatchProjectOp) -> Result<String> {
        let target_phase = batch
            .target_phase
            .as_ref()
            .ok_or_else(|| anyhow!("target_phase required for transition operation"))?;

        // In production, this would call the actual phase transition logic
        Ok(format!(
            "Transitioned project '{}' to phase '{}'",
            project_op.project, target_phase
        ))
    }

    fn batch_security(project_op: &BatchProjectOp) -> Result<String> {
        // In production, this would call the actual security assessment logic
        Ok(format!(
            "Ran security assessment for project '{}'",
            project_op.project
        ))
    }

    /// Export batch results to file
    pub fn export_results(results: &[BatchResult], path: impl AsRef<Path>) -> Result<()> {
        let content = serde_json::to_string_pretty(results)?;
        std::fs::write(path, content)?;
        Ok(())
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_batch_result_creation() {
        let result = BatchResult {
            project: "test-project".to_string(),
            success: true,
            message: "Success".to_string(),
            error: None,
        };

        assert_eq!(result.project, "test-project");
        assert!(result.success);
        assert!(result.error.is_none());
    }

    #[test]
    fn test_batch_project_op() {
        let op = BatchProjectOp {
            project: "my-project".to_string(),
            data: serde_json::json!({"name": "My Project"}),
        };

        assert_eq!(op.project, "my-project");
    }

    #[test]
    fn test_batch_operation_defaults() {
        let batch = BatchOperation {
            operation_type: "create".to_string(),
            target_phase: None,
            projects: vec![],
            stop_on_error: false,
            parallel: false,
            max_workers: 1,
        };

        assert!(!batch.stop_on_error);
        assert!(!batch.parallel);
    }

    #[test]
    fn test_empty_batch_fails() {
        let batch = BatchOperation {
            operation_type: "create".to_string(),
            target_phase: None,
            projects: vec![],
            stop_on_error: true,
            parallel: false,
            max_workers: 1,
        };

        let result = BatchHandler::execute(&batch);
        assert!(result.is_err());
    }

    #[test]
    fn test_batch_create_operation() {
        let op = BatchProjectOp {
            project: "test".to_string(),
            data: serde_json::json!({"name": "Test Project"}),
        };

        let result = BatchHandler::batch_create(&op);
        assert!(result.is_ok());
        assert!(result.unwrap().contains("Created"));
    }

    #[test]
    fn test_batch_transition_requires_target_phase() {
        let batch = BatchOperation {
            operation_type: "transition".to_string(),
            target_phase: None,
            projects: vec![],
            stop_on_error: true,
            parallel: false,
            max_workers: 1,
        };

        let op = BatchProjectOp {
            project: "test".to_string(),
            data: serde_json::Value::Null,
        };

        let result = BatchHandler::batch_transition(&batch, &op);
        assert!(result.is_err());
    }
}
