package protocol

import "strings"

const maxRunLogicalFileKeyLength = 160

func ValidateRunJobAssignment(assignment RunJobAssignment) error {
	if assignment.JobID == "" || assignment.RunEndpointID == "" || assignment.Capability == "" {
		return ValidationError("jobId, runEndpointId, and capability are required")
	}
	switch assignment.Capability {
	case RunCapabilityConfigWrite, RunCapabilityFilesRead, RunCapabilityFilesWrite:
		if assignment.ServerInstanceID == "" {
			return ValidationError("serverInstanceId is required for scoped file jobs")
		}
		if !ValidLogicalFileKey(assignment.TargetKey) {
			return ValidationError("targetKey is not allowed")
		}
	}
	switch assignment.Capability {
	case RunCapabilityConfigWrite, RunCapabilityFilesWrite:
		if !ValidScopedInputRef(assignment.InputRef) {
			return ValidationError("inputRef is not allowed")
		}
	}
	if IsRemoteCapability(assignment.Capability) {
		if assignment.ServerInstanceID == "" {
			return ValidationError("serverInstanceId is required for remote jobs")
		}
		if RemoteCapabilityRequiresTargetKey(assignment.Capability) && !ValidLogicalFileKey(assignment.TargetKey) {
			return ValidationError("targetKey is not allowed")
		}
		if RemoteCapabilityRequiresInputRef(assignment.Capability) && !ValidScopedInputRef(assignment.InputRef) {
			return ValidationError("inputRef is not allowed")
		}
	}
	switch assignment.Capability {
	case RunCapabilityRunSelfUpdate:
		if assignment.ServerInstanceID == "" {
			return ValidationError("serverInstanceId is required for self-update jobs")
		}
		if assignment.TargetKey != "run/update" {
			return ValidationError("targetKey must be run/update")
		}
		if !ValidScopedInputRef(assignment.InputRef) || !strings.HasPrefix(assignment.InputRef, "artifact://") {
			return ValidationError("inputRef must be an artifact ref for self-update")
		}
	case RunCapabilityDependenciesCheck, RunCapabilityDependenciesInstall:
		if assignment.ServerInstanceID == "" {
			return ValidationError("serverInstanceId is required for dependency jobs")
		}
		if !ValidLogicalFileKey(assignment.TargetKey) || !strings.HasPrefix(assignment.TargetKey, "dependencies/") {
			return ValidationError("targetKey is not allowed for dependency jobs")
		}
		if assignment.InputRef != "" {
			return ValidationError("dependency jobs must not carry arbitrary input refs")
		}
	case RunCapabilityLogsBackfill:
		if assignment.ServerInstanceID == "" {
			return ValidationError("serverInstanceId is required for log backfill jobs")
		}
		if !ValidLogicalFileKey(assignment.TargetKey) || !strings.HasPrefix(assignment.TargetKey, "logs/") {
			return ValidationError("targetKey is not allowed for log backfill jobs")
		}
		if assignment.InputRef != "" && !ValidScopedInputRef(assignment.InputRef) {
			return ValidationError("inputRef is not allowed for log backfill jobs")
		}
	}
	return nil
}

type ValidationError string

func (err ValidationError) Error() string { return string(err) }

func ValidLogicalFileKey(key string) bool {
	trimmed := strings.TrimSpace(key)
	if trimmed == "" || trimmed != key || len([]rune(key)) > maxRunLogicalFileKeyLength {
		return false
	}
	lower := strings.ToLower(key)
	if strings.HasPrefix(key, "/") || strings.Contains(key, "..") || strings.Contains(key, `\`) || strings.Contains(key, "://") || strings.Contains(lower, "/users/") || strings.Contains(lower, "password=") || strings.Contains(lower, "secret=") || strings.Contains(lower, "sk-") || strings.Contains(lower, "bearer ") {
		return false
	}
	for _, char := range key {
		if (char >= 'a' && char <= 'z') || (char >= 'A' && char <= 'Z') || (char >= '0' && char <= '9') || char == '_' || char == '-' || char == '.' || char == '/' {
			continue
		}
		return false
	}
	return true
}

func ValidScopedInputRef(ref string) bool {
	trimmed := strings.TrimSpace(ref)
	lower := strings.ToLower(ref)
	if trimmed == "" || trimmed != ref || strings.Contains(lower, "/users/") || strings.Contains(lower, "password=") || strings.Contains(lower, "secret=") || strings.Contains(lower, "sk-") || strings.Contains(lower, "bearer ") {
		return false
	}
	return strings.HasPrefix(ref, "input://") || strings.HasPrefix(ref, "artifact://")
}

func IsRemoteCapability(capability string) bool {
	return strings.HasPrefix(capability, "remote.")
}

func RemoteCapabilityRequiresTargetKey(capability string) bool {
	switch capability {
	case RunCapabilityRemoteRunProcessStart, RunCapabilityRemoteRunProcessStop:
		return false
	default:
		return IsRemoteCapability(capability)
	}
}

func RemoteCapabilityRequiresInputRef(capability string) bool {
	switch capability {
	case RunCapabilityRemoteFTPWrite,
		RunCapabilityRemoteRsyncWrite,
		RunCapabilityRemoteRunFilesWrite,
		RunCapabilityRemoteRunDBMySQLQuery,
		RunCapabilityRemoteRunDBSQLiteQuery,
		RunCapabilityRemoteRunRCONCommand:
		return true
	default:
		return false
	}
}