prax-cli 0.3.2

//! `prax migrate` commands - Database migration management.

use std::path::PathBuf;

use crate::cli::MigrateArgs;
use crate::commands::seed::{find_seed_file, get_database_url, SeedRunner};
use crate::config::{Config, CONFIG_FILE_NAME, MIGRATIONS_DIR, SCHEMA_FILE_NAME};
use crate::error::{CliError, CliResult};
use crate::output::{self, success, warn};

/// Run the migrate command
pub async fn run(args: MigrateArgs) -> CliResult<()> {
    match args.command {
        crate::cli::MigrateSubcommand::Dev(dev_args) => run_dev(dev_args).await,
        crate::cli::MigrateSubcommand::Deploy => run_deploy().await,
        crate::cli::MigrateSubcommand::Reset(reset_args) => run_reset(reset_args).await,
        crate::cli::MigrateSubcommand::Status => run_status().await,
        crate::cli::MigrateSubcommand::Resolve(resolve_args) => run_resolve(resolve_args).await,
        crate::cli::MigrateSubcommand::Diff(diff_args) => run_diff(diff_args).await,
    }
}

/// Run `prax migrate dev` - development migration workflow
async fn run_dev(args: crate::cli::MigrateDevArgs) -> CliResult<()> {
    output::header("Migrate Dev");

    let cwd = std::env::current_dir()?;
    let config = load_config(&cwd)?;

    let schema_path = args.schema.clone().unwrap_or_else(|| cwd.join(SCHEMA_FILE_NAME));
    let migrations_dir = cwd.join(MIGRATIONS_DIR);

    output::kv("Schema", &schema_path.display().to_string());
    output::kv("Migrations", &migrations_dir.display().to_string());
    output::newline();

    // Determine total steps (5 or 6 depending on seed)
    let total_steps = if args.skip_seed { 5 } else { 6 };

    // 1. Parse and validate schema
    output::step(1, total_steps, "Parsing schema...");
    let schema_content = std::fs::read_to_string(&schema_path)?;
    let schema = parse_schema(&schema_content)?;

    // 2. Check for pending migrations
    output::step(2, total_steps, "Checking migration status...");
    let pending = check_pending_migrations(&migrations_dir)?;

    if !pending.is_empty() {
        output::list(&format!("{} pending migrations found:", pending.len()));
        for migration in &pending {
            output::list_item(&migration.display().to_string());
        }
        output::newline();
    }

    // 3. Diff schema against database
    output::step(3, total_steps, "Comparing schema to database...");
    let migration_name = args.name.unwrap_or_else(|| {
        format!(
            "migration_{}",
            chrono::Utc::now().format("%Y%m%d%H%M%S")
        )
    });

    // 4. Generate migration
    output::step(4, total_steps, "Generating migration...");
    let migration_path = create_migration(&migrations_dir, &migration_name, &schema)?;

    // 5. Apply migration (if not --create-only)
    if !args.create_only {
        output::step(5, total_steps, "Applying migration...");
        apply_migration(&migration_path, &config).await?;
    } else {
        output::step(5, total_steps, "Skipping apply (--create-only)...");
    }

    // 6. Run seed (if not --skip-seed)
    if !args.skip_seed && !args.create_only {
        output::step(6, total_steps, "Running seed...");

        if let Some(seed_path) = find_seed_file(&cwd, &config) {
            let database_url = get_database_url(&config)?;
            let runner = SeedRunner::new(
                seed_path,
                database_url,
                config.database.provider.clone(),
                cwd.clone(),
            )?;

            match runner.run().await {
                Ok(result) => {
                    output::list_item(&format!("Seeded {} records", result.records_affected));
                }
                Err(e) => {
                    output::warn(&format!("Seed failed: {}. Continuing...", e));
                }
            }
        } else {
            output::list_item("No seed file found, skipping");
        }
    }

    output::newline();
    success(&format!("Migration '{}' created", migration_name));

    output::newline();
    output::section("Next steps");
    output::list_item("Review the generated migration SQL");
    output::list_item("Run `prax generate` to update your client");

    Ok(())
}

/// Run `prax migrate deploy` - production deployment
async fn run_deploy() -> CliResult<()> {
    output::header("Migrate Deploy");

    let cwd = std::env::current_dir()?;
    let config = load_config(&cwd)?;
    let migrations_dir = cwd.join(MIGRATIONS_DIR);

    output::kv("Migrations", &migrations_dir.display().to_string());
    output::newline();

    // Check for pending migrations
    output::step(1, 3, "Checking for pending migrations...");
    let pending = check_pending_migrations(&migrations_dir)?;

    if pending.is_empty() {
        output::newline();
        success("No pending migrations to apply.");
        return Ok(());
    }

    output::list(&format!("{} pending migrations:", pending.len()));
    for migration in &pending {
        output::list_item(&migration.file_name().unwrap().to_string_lossy());
    }
    output::newline();

    // Apply migrations
    output::step(2, 3, "Applying migrations...");
    for migration in &pending {
        output::list_item(&format!("Applying {}", migration.file_name().unwrap().to_string_lossy()));
        apply_migration(migration, &config).await?;
    }

    // Verify
    output::step(3, 3, "Verifying migrations...");

    output::newline();
    success(&format!(
        "Applied {} migrations successfully!",
        pending.len()
    ));

    Ok(())
}

/// Run `prax migrate reset` - reset database
async fn run_reset(args: crate::cli::MigrateResetArgs) -> CliResult<()> {
    output::header("Migrate Reset");

    let cwd = std::env::current_dir()?;
    let config = load_config(&cwd)?;

    if !args.force {
        warn("This will delete all data in the database!");
        output::newline();
        if !output::confirm("Are you sure you want to reset the database?") {
            output::newline();
            output::info("Reset cancelled.");
            return Ok(());
        }
    }

    output::newline();
    output::step(1, 4, "Dropping database...");
    // TODO: Implement database drop

    output::step(2, 4, "Creating database...");
    // TODO: Implement database create

    output::step(3, 4, "Applying migrations...");
    let migrations_dir = cwd.join(MIGRATIONS_DIR);
    let migrations = check_pending_migrations(&migrations_dir)?;

    for migration in &migrations {
        apply_migration(migration, &config).await?;
    }

    // Run seed if requested
    if args.seed {
        output::step(4, 4, "Running seed...");

        // Find and run seed file
        if let Some(seed_path) = find_seed_file(&cwd, &config) {
            let database_url = get_database_url(&config)?;
            let runner = SeedRunner::new(
                seed_path,
                database_url,
                config.database.provider.clone(),
                cwd,
            )?;

            let result = runner.run().await?;
            output::list_item(&format!("Seeded {} records", result.records_affected));
        } else {
            output::list_item("No seed file found, skipping seed");
        }
    } else {
        output::step(4, 4, "Skipping seed...");
    }

    output::newline();
    success("Database reset complete!");

    Ok(())
}

/// Run `prax migrate status` - show migration status
async fn run_status() -> CliResult<()> {
    output::header("Migration Status");

    let cwd = std::env::current_dir()?;
    let _config = load_config(&cwd)?;
    let migrations_dir = cwd.join(MIGRATIONS_DIR);

    // List all migrations
    let mut migrations = Vec::new();
    if migrations_dir.exists() {
        for entry in std::fs::read_dir(&migrations_dir)? {
            let entry = entry?;
            let path = entry.path();
            if path.is_dir() {
                migrations.push(path);
            }
        }
    }
    migrations.sort();

    if migrations.is_empty() {
        output::info("No migrations found.");
        output::newline();
        output::section("Getting started");
        output::list_item("Run `prax migrate dev` to create your first migration");
        return Ok(());
    }

    output::section("Migrations");

    for (i, migration) in migrations.iter().enumerate() {
        let name = migration.file_name().unwrap().to_string_lossy();
        let applied = is_migration_applied(migration)?;

        let status = if applied {
            output::style_success("✓ Applied")
        } else {
            output::style_pending("○ Pending")
        };

        output::numbered_item(i + 1, &format!("{} - {}", name, status));
    }

    output::newline();

    let applied_count = migrations.iter().filter(|m| is_migration_applied(m).unwrap_or(false)).count();
    let pending_count = migrations.len() - applied_count;

    output::kv("Total", &migrations.len().to_string());
    output::kv("Applied", &applied_count.to_string());
    output::kv("Pending", &pending_count.to_string());

    Ok(())
}

/// Run `prax migrate resolve` - resolve migration issues
async fn run_resolve(args: crate::cli::MigrateResolveArgs) -> CliResult<()> {
    output::header("Migrate Resolve");

    if args.rolled_back {
        output::step(1, 2, "Marking migration as rolled back...");
        // TODO: Mark migration as rolled back in history table

        output::step(2, 2, "Updating migration history...");

        output::newline();
        success(&format!(
            "Migration '{}' marked as rolled back",
            args.migration
        ));
    } else if args.applied {
        output::step(1, 2, "Marking migration as applied...");
        // TODO: Mark migration as applied in history table

        output::step(2, 2, "Updating migration history...");

        output::newline();
        success(&format!(
            "Migration '{}' marked as applied",
            args.migration
        ));
    } else {
        return Err(CliError::Command(
            "Must specify --applied or --rolled-back".to_string()
        ).into());
    }

    Ok(())
}

/// Run `prax migrate diff` - generate migration diff without applying
async fn run_diff(args: crate::cli::MigrateDiffArgs) -> CliResult<()> {
    output::header("Migrate Diff");

    let cwd = std::env::current_dir()?;
    let schema_path = args.schema.unwrap_or_else(|| cwd.join(SCHEMA_FILE_NAME));

    // Parse schema
    output::step(1, 3, "Parsing schema...");
    let schema_content = std::fs::read_to_string(&schema_path)?;
    let schema = parse_schema(&schema_content)?;

    // Get current database state
    output::step(2, 3, "Introspecting database...");
    // TODO: Implement database introspection

    // Generate diff
    output::step(3, 3, "Generating diff...");
    let diff_sql = generate_schema_diff(&schema)?;

    output::newline();

    if diff_sql.is_empty() {
        success("Schema is in sync with database - no changes needed");
    } else {
        output::section("Generated SQL");
        output::code(&diff_sql, "sql");

        if let Some(output_path) = args.output {
            std::fs::write(&output_path, &diff_sql)?;
            output::newline();
            success(&format!("Diff written to {}", output_path.display()));
        }
    }

    Ok(())
}

// =============================================================================
// Helper Functions
// =============================================================================

fn load_config(cwd: &PathBuf) -> CliResult<Config> {
    let config_path = cwd.join(CONFIG_FILE_NAME);
    if config_path.exists() {
        Config::load(&config_path)
    } else {
        Ok(Config::default())
    }
}

fn parse_schema(content: &str) -> CliResult<prax_schema::Schema> {
    prax_schema::parse_schema(content)
        .map_err(|e| CliError::Schema(format!("Failed to parse schema: {}", e)))
}

fn check_pending_migrations(migrations_dir: &PathBuf) -> CliResult<Vec<PathBuf>> {
    let mut pending = Vec::new();

    if !migrations_dir.exists() {
        return Ok(pending);
    }

    for entry in std::fs::read_dir(migrations_dir)? {
        let entry = entry?;
        let path = entry.path();
        if path.is_dir() {
            if !is_migration_applied(&path)? {
                pending.push(path);
            }
        }
    }

    pending.sort();
    Ok(pending)
}

fn is_migration_applied(migration_path: &PathBuf) -> CliResult<bool> {
    // Check for a marker file indicating the migration has been applied
    // In production, this would check the migration history table
    let marker = migration_path.join(".applied");
    Ok(marker.exists())
}

fn create_migration(
    migrations_dir: &PathBuf,
    name: &str,
    schema: &prax_schema::ast::Schema,
) -> CliResult<PathBuf> {
    // Create migration directory
    let timestamp = chrono::Utc::now().format("%Y%m%d%H%M%S");
    let migration_name = format!("{}_{}", timestamp, name);
    let migration_path = migrations_dir.join(&migration_name);

    std::fs::create_dir_all(&migration_path)?;

    // Generate migration SQL
    let sql = generate_schema_diff(schema)?;

    // Write migration.sql
    let sql_path = migration_path.join("migration.sql");
    std::fs::write(&sql_path, &sql)?;

    Ok(migration_path)
}

fn generate_schema_diff(schema: &prax_schema::ast::Schema) -> CliResult<String> {
    use prax_schema::ast::{FieldType, ScalarType};

    let mut sql = String::new();

    sql.push_str("-- Migration generated by Prax\n\n");

    // Generate CREATE TABLE statements for each model
    for model in schema.models.values() {
        let table_name = model.table_name();

        sql.push_str(&format!("CREATE TABLE IF NOT EXISTS \"{}\" (\n", table_name));

        let mut columns = Vec::new();
        let mut primary_keys = Vec::new();

        for field in model.fields.values() {
            if field.is_relation() {
                continue;
            }

            let column_name = field
                .get_attribute("map")
                .and_then(|a| a.first_arg())
                .and_then(|v| v.as_string())
                .map(|s| s.to_string())
                .unwrap_or_else(|| to_snake_case(field.name()));

            let sql_type = field_type_to_sql(&field.field_type);
            let mut column_def = format!("    \"{}\" {}", column_name, sql_type);

            // Add constraints
            if field.is_id() {
                primary_keys.push(column_name.clone());
            }

            if field.has_attribute("auto") || field.has_attribute("autoincrement") {
                // PostgreSQL uses SERIAL types
                column_def = format!(
                    "    \"{}\" SERIAL",
                    column_name
                );
            }

            if field.has_attribute("unique") {
                column_def.push_str(" UNIQUE");
            }

            if !field.is_optional() && !field.is_id() {
                column_def.push_str(" NOT NULL");
            }

            // Default values
            if let Some(default_attr) = field.get_attribute("default") {
                if let Some(value) = default_attr.first_arg() {
                    let value_str = format_attribute_value(value);
                    column_def.push_str(&format!(
                        " DEFAULT {}",
                        sql_default_value(&value_str)
                    ));
                }
            }

            columns.push(column_def);
        }

        sql.push_str(&columns.join(",\n"));

        if !primary_keys.is_empty() {
            sql.push_str(",\n");
            sql.push_str(&format!(
                "    PRIMARY KEY (\"{}\")",
                primary_keys.join("\", \"")
            ));
        }

        sql.push_str("\n);\n\n");
        sql.push_str("\n");
    }

    // Generate enums
    for enum_def in schema.enums.values() {
        let enum_name = enum_def
            .attributes
            .iter()
            .find(|a| a.is("map"))
            .and_then(|a: &prax_schema::ast::Attribute| a.first_arg())
            .and_then(|v: &prax_schema::ast::AttributeValue| v.as_string())
            .map(|s| s.to_string())
            .unwrap_or_else(|| to_snake_case(enum_def.name()));

        sql.push_str(&format!(
            "DO $$ BEGIN\n    CREATE TYPE \"{}\" AS ENUM (",
            enum_name
        ));

        let variants: Vec<String> = enum_def
            .variants
            .iter()
            .map(|v| format!("'{}'", v.name()))
            .collect();

        sql.push_str(&variants.join(", "));
        sql.push_str(");\nEXCEPTION\n    WHEN duplicate_object THEN null;\nEND $$;\n\n");
    }

    return Ok(sql);

    fn field_type_to_sql(field_type: &FieldType) -> String {
        match field_type {
            FieldType::Scalar(scalar) => match scalar {
                ScalarType::Int => "INTEGER".to_string(),
                ScalarType::BigInt => "BIGINT".to_string(),
                ScalarType::Float => "DOUBLE PRECISION".to_string(),
                ScalarType::String => "TEXT".to_string(),
                ScalarType::Boolean => "BOOLEAN".to_string(),
                ScalarType::DateTime => "TIMESTAMP WITH TIME ZONE".to_string(),
                ScalarType::Date => "DATE".to_string(),
                ScalarType::Time => "TIME".to_string(),
                ScalarType::Json => "JSONB".to_string(),
                ScalarType::Bytes => "BYTEA".to_string(),
                ScalarType::Decimal => "DECIMAL".to_string(),
                ScalarType::Uuid => "UUID".to_string(),
                ScalarType::Cuid | ScalarType::Cuid2 | ScalarType::NanoId | ScalarType::Ulid => {
                    "TEXT".to_string()
                }
            },
            FieldType::Enum(name) => format!("\"{}\"", to_snake_case(name)),
            _ => "TEXT".to_string(),
        }
    }
}

async fn apply_migration(migration_path: &PathBuf, _config: &Config) -> CliResult<()> {
    let sql_path = migration_path.join("migration.sql");

    if !sql_path.exists() {
        return Err(CliError::Migration(format!(
            "Migration file not found: {}",
            sql_path.display()
        )));
    }

    let _sql = std::fs::read_to_string(&sql_path)?;

    // TODO: Execute SQL against database
    // This would use the database URL from config

    // Mark as applied
    let marker = migration_path.join(".applied");
    std::fs::write(&marker, chrono::Utc::now().to_rfc3339())?;

    Ok(())
}

fn sql_default_value(value: &str) -> String {
    match value.to_lowercase().as_str() {
        "now()" => "CURRENT_TIMESTAMP".to_string(),
        "uuid()" => "gen_random_uuid()".to_string(),
        "cuid()" | "cuid2()" | "nanoid()" | "ulid()" => {
            // These need application-level generation
            "''".to_string()
        }
        "true" => "TRUE".to_string(),
        "false" => "FALSE".to_string(),
        _ => value.to_string(),
    }
}

fn to_snake_case(name: &str) -> String {
    let mut result = String::new();
    for (i, c) in name.chars().enumerate() {
        if c.is_uppercase() {
            if i > 0 {
                result.push('_');
            }
            result.push(c.to_lowercase().next().unwrap());
        } else {
            result.push(c);
        }
    }
    result
}

fn format_attribute_value(value: &prax_schema::ast::AttributeValue) -> String {
    use prax_schema::ast::AttributeValue;

    match value {
        AttributeValue::String(s) => format!("\"{}\"", s),
        AttributeValue::Int(i) => i.to_string(),
        AttributeValue::Float(f) => f.to_string(),
        AttributeValue::Boolean(b) => b.to_string(),
        AttributeValue::Ident(id) => id.to_string(),
        AttributeValue::Function(name, args) => {
            if args.is_empty() {
                format!("{}()", name)
            } else {
                let arg_strs: Vec<String> = args.iter().map(format_attribute_value).collect();
                format!("{}({})", name, arg_strs.join(", "))
            }
        }
        AttributeValue::Array(items) => {
            let item_strs: Vec<String> = items.iter().map(format_attribute_value).collect();
            format!("[{}]", item_strs.join(", "))
        }
        AttributeValue::FieldRef(field) => field.to_string(),
        AttributeValue::FieldRefList(fields) => {
            format!(
                "[{}]",
                fields
                    .iter()
                    .map(|f| f.to_string())
                    .collect::<Vec<_>>()
                    .join(", ")
            )
        }
    }
}