#!/usr/bin/env nu
# Generate .sops.yaml configuration files
# Fetches Age public keys from vault-service and creates environment-specific SOPS rules
# Usage: sops-init [--environment dev|staging|prod] [--output-dir <path>] [--validate]

use std log

def get-vault-url [] {
    $env.VAULT_SERVICE_URL? // "http://localhost:9094"
}

def get-vault-token [] {
    $env.VAULT_SERVICE_TOKEN? // ""
}

def fetch-age-public-key [environment: string] {
    let url = $"(get-vault-url)/api/v1/age/get-public?env=($environment)"
    let token = (get-vault-token)

    let headers = if ($token | is-empty) {
        {}
    } else {
        {"X-Vault-Token": $token}
    }

    let response = (http get -H $headers $url | complete)

    if $response.exit_code != 0 {
        error make {
            msg: "Cannot connect to vault-service"
            label: {
                text: $"Check VAULT_SERVICE_URL (set to: (get-vault-url))"
                span: (metadata $environment).span
            }
        }
    }

    let json = ($response.stdout | from json)
    $json.public_key
}

def generate-sops-yaml [environment: string, public_key: string] {
    let encrypted_regex = match $environment {
        "dev" => "^(password|token|key|secret|api_key)$",
        "staging" => "^(password|token|key|secret|api_key|database_url)$",
        "prod" => "^(password|token|key|secret|api_key|database_url|tls_cert|tls_key)$",
        _ => "^(password|token|key|secret|api_key)$"
    }

    let extension = match $environment {
        "dev" => ".dev.yaml",
        "staging" => ".staging.yaml",
        "prod" => ".prod.yaml",
        _ => ".yaml"
    }

    let header = "# SOPS creation rules - evaluated sequentially, first match wins"
    let rule1 = $"    - path_regex: \\($extension)$"
    let rule1_age = $"      age: '$public_key'"
    let rule1_regex = $"      encrypted_regex: '$encrypted_regex'"
    let rule2 = "    -"
    let rule2_age = $"      age: '$public_key'"
    let rule2_regex = $"      encrypted_regex: '$encrypted_regex'"

    $"$header
creation_rules:
$rule1
$rule1_age
$rule1_regex

$rule2
$rule2_age
$rule2_regex
"
}

def validate-sops-yaml [yaml_content: string] {
    let has_creation_rules = ($yaml_content | str contains "creation_rules:")
    let has_age_key = ($yaml_content | str contains "age:")
    let has_public_key = ($yaml_content | str contains "age1")  # Age keys start with "age1"

    if not $has_creation_rules {
        error make {
            msg: "Invalid SOPS YAML: missing creation_rules section"
            label: { text: "YAML must have creation_rules" }
        }
    }

    if not $has_age_key {
        error make {
            msg: "Invalid SOPS YAML: missing age key configuration"
            label: { text: "Each rule must have an age key" }
        }
    }

    if not $has_public_key {
        error make {
            msg: "Invalid SOPS YAML: Age public key format invalid"
            label: { text: "Public key should start with 'age1'" }
        }
    }

    true
}

def determine-output-path [environment: string, output_dir: string] {
    let dir = if ($output_dir | is-empty) {
        match $environment {
            "dev" => "config/secrets/dev",
            "staging" => "config/secrets/staging",
            "prod" => "config/secrets/prod",
            _ => "config/secrets"
        }
    } else {
        $output_dir
    }

    $"($dir)/.sops.yaml"
}

def main [
    --environment: string = "dev"
    --output-dir: string = ""
    --validate
] {
    # Validate environment
    if $environment not-in ["dev", "staging", "prod"] {
        error make {
            msg: "Invalid environment"
            label: {
                text: "Must be: dev, staging, or prod"
                span: (metadata $environment).span
            }
        }
    }

    print $"🔐 Generating .sops.yaml for ($environment) environment..."

    # Fetch Age public key
    print $"Fetching Age public key from vault-service..."
    let public_key = (fetch-age-public-key $environment)
    print $"✓ Age public key retrieved: ($public_key | str substring 0..20)..."

    # Generate SOPS configuration
    print "Generating SOPS rules..."
    let sops_yaml = (generate-sops-yaml $environment $public_key)

    # Validate if requested
    if $validate {
        print "Validating SOPS YAML configuration..."
        let valid = (validate-sops-yaml $sops_yaml)
        if $valid {
            print "✓ SOPS configuration is valid"
        }
    }

    # Determine output path
    let output_path = (determine-output-path $environment $output_dir)
    let output_dir_path = ($output_path | path dirname)

    # Create directory if needed
    if not ($output_dir_path | path exists) {
        print $"Creating directory: ($output_dir_path)"
        ^mkdir -p $output_dir_path
    }

    # Write .sops.yaml file
    print $"Writing .sops.yaml to ($output_path)"
    $sops_yaml | save -f $output_path

    print ""
    print "✓ SOPS configuration generated successfully"
    print $"Location: ($output_path)"
    print $"Environment: ($environment)"
    print $"Age public key: ($public_key | str substring 0..30)..."

    {
        success: true
        environment: $environment
        output_path: $output_path
        public_key: ($public_key | str substring 0..30)
        message: "SOPS .yaml configuration created"
    }
}